From Embryology

Lab Attendance

Individual Assessment

Lab 1

--Z3418837 (talk) 12:45, 6 August 2014 (EST)




Your Lab assessment now requires you to find a 2 recent research references on fertilisation or in vitro fertilisation. Paste each reference on your page, as shown in the class. Write below each reference a brief summary of the research article methods and findings. The summary for each need not be more than 3-4 paragraphs in length. This will need to be completed before next weeks laboratory.



This study was designed to investigate whether the levels of vitamin D is an imperative factor when it comes to the clinical success of implantation and pregnancy rates in infertile women via invitro fertilisation.

Method summary

A cohort of 173 women were evaluated and selected for this study based on their age, follicle-stimulating hormone levels and their consent to undergo invitro fertilisation. The following study was conducted at Mount Sinai Hospital where proper facilities were available. Blood tests were then conducted for each patient to determine their levels of Vitamin D via the serum 25-hydroxy-vitamin D (25[OH]D) levels. Following the results of the blood test, the cohort were then categorised into two groups which was either vitamin D sufficient (≥ 75 nmol/L) or insufficient ( < 75 nmol/L) based on serum levels of 25(OH)D.

Each patient then underwent IVF cycles whereby standard agonists that contained the active ingredient 0.5 mg/d of buserelin acetate in conjunction with cetrolix acetate as the standard antagonist were used to control the length of the luteal phase and estradiol levels. The length and dose of the treatment were varied for each individual based on their demographic data. Serial transvaginal ultrasonograpy and serum lutenizing hormone assays were then used to check ovarian response. When 3 or more dominant follicles (≥ 17 mm) were produced, 10 000 IU of human chorionic gonadotropin was added to enhance nuclear maturation. Oocyte retrieval was then conducted via transvaginal ultrasound whereby it was fertilised and the resulting embryo was transferred 3-5 days post-fertilisation. The rate of pregnancy per IVF cycle was then used as the primary outcome for this study whereby the visibility of the intrauterine sac of the embryo determined implantation.

Results summary

Out of the 182 patients that participated in this study, it was found that only 173 patients could continue on with this trial as they satisfied the criteria, however only 162 were fit for embryo transfer. Following the results from the blood test, it was noted that 53.8% of patients had insufficient levels of 25(OH)D and 45.1% had sufficient amounts. It was discovered that 71.8% of those with sufficient levels of 25(OH)D were more likely to proceed with embryo transfer on day 5 compared to 58.9% (p = 0.054) of those assigned to the ‘insufficient 25(OH)D’ category. Other factors such as oocyte retrieval and frequency of intracytoplasmic sperm injection were fairly similar in both groups. The study revealed that there was a higher clinical pregnancy rate per IVF cycle for those assigned to the sufficient 25(OH)D level category by 52.5% compared to those with insufficient amounts of 25(OH)D which was 34.7% (p < 0.001). Similarly, there was a significant clinical pregnancy rate per embryo transfer of 54.7% in comparison to 37.9% in woman belonging to the sufficient and insufficient category respectively. It was also noted that the implantation rate was greater in the sufficient category compared to the insufficient group, however the difference was only minimal (p= 0.6). Overall, the results suggest that serum 25(OH)D levels may be a predictor of clinical pregnancy.



The process of achieving pregnancy via invitro fertilisation needs to be monitored and controlled with respect to the demographics of the individual in order to achieve a successful outcome. This study focuses on predicting the value of β-human chorionic gonadotrophin (β-HCG) that can lead to clinical success.

Method summary

Data analysis was taken from 171 female patients using the statistical package for social sciences program whereby all IVF cycles were monitored. The cycles that showed fresh multi-cell embryos (day 3) or blastocysts (day 5) were deemed fit for the trial and were the ones that were further used in this study. Serum β-HCG concentrations were then taken 14 days after the embryo was transferred whereby a second test was done on day 16 only if the first test revealed a positive β-HCG result. This was done to predict values that could enable doctors to evaluate a healthy intrauterine pregnancy or a problematic ectopic pregnancy. After 6-7 weeks of pregnancy, ultrasounds were conducted to check cardiac activity as well as the amount of gestational sacs. This was then repeated at 12 weeks of pregnancy to ensure there was no chance of abortion.

A continuing pregnancy was defined as one that continued for at least 12 weeks of gestation and showed signs of proper cardiac function. On the other hand, those pregnancies that were abnormal had dropped levels of β-HCG concentrations and led to empty gestational sacs that showed no embryonic cardiac function. As a measuring tool for detecting levels of β-HCG, Chemiluminescent microparticle immunoassays were used whereby the measuring range established was between 0.0-15,000 mIU/mL. HCG levels above 10 IU/L signified early pregnancy.

Results Summary

Out of the 171 patients that participated in this study, only 139 were included due to the missing data on the levels of β-HCG concentrations at day 14 and 16 post embryonic transfer. In total there were 39 abnormal pregnancies that involved ectopic pregnancy, abortions and biochemical pregnancies (sufficient HCG levels detected but no visible gestational sac). Overall the patients were categorised into two groups which were patients with ‘ongoing pregnancy’ (n=100) and ‘without ongoing pregnancy’ (n=39). The Mann-Whitney test (statistical testing) was then used to compare the levels of β-HCG levels in both groups. It was found that the group with ongoing pregnancy had a median serum β-HCG level of 600 mIU/ml, whereas the other group had a median serum β-HCG level of 178 mIU/ml. This indicated a significant difference of P < 0.05 when comparing the two groups. It was also found that when serum β-HCG levels reached 347 mIU/ml, there was a 73.6% chance that the pregnancy was ongoing. Furthermore, there was no definite correlation established between age and the rate of ongoing pregnancy as both categories had patients of similar age groups with a combined range of 23-41 year old patients. Overall, the study revealed that early serum β-HCG is a potential predictor of successful outcomes in invitro fertilisation.

--Mark Hill (talk) 19:11, 6 October 2014 (EST) These are relevant references and your descriptions/abstracts are good (5/5).

Lab 2

Phase-contrast images of embryos at different developmental stages via neogenin expression.png

Phase-contrast images of embryos at different developmental stages via neogenin expression.[1]

--Mark Hill (talk) 16:17, 21 August 2014 (EST) This is all correct. The image is very large (4.8 MB), perhaps a small version could have been uploaded. You can adjust the resolution and size in most image editing programs. (5/5)

  1. <pubmed>25013897</pubmed>| PLos One

Lab 3

Parathyroid gland

<pubmed>22808183</pubmed> <pubmed>22649358</pubmed> <pubmed>21881196</pubmed> <pubmed>21904825</pubmed>


<pubmed>21733645</pubmed> <pubmed>20836742</pubmed> <pubmed>21263742</pubmed> <pubmed>512270</pubmed>


<pubmed>22761699</pubmed> <pubmed>22893718</pubmed> <pubmed>24496309</pubmed> <pubmed>24595965</pubmed> <pubmed>23822675</pubmed> <pubmed>22968764</pubmed>

--[[User:Z8600021|Mark Hill] These references are appropriate, you should have included some descriptions, even a single line, with the reference (4/5).

Lab 4

1. Identify a paper that uses cord stem cells therapeutically and write a brief (2-3 paragraph) description of the paper's findings.

Regulation of Glioblastoma Progression by Cord Blood Stem Cells Is Mediated by Downregulation of Cyclin D1

Glioblastoma multiforme (GBM) is known to belong to a very life threatening form of brain cancer. Research is currently focused on finding treatments regarding such abnormalities, such as the application of neuronal stem cells in reducing the population of tumours, however there were many problems that occurred with such treatment. Recently, Human umbilical cord blood derived stem cells (hUCBSC) has been extensively used as they are useful mesenchymal stem cells that are easy to isolate and are more available. GBM is caused by the overexpression of cyclin D1 and its subsequent binding to Cdk 4/Cdk 6 which defines the rate limiting step required for the cell to progress further on to the cell cycle from the G1 phase. In order to stop this over expression, scientists have used hUCBSC to inhibit the cell from progressing on with the cell cycle.

When (hUCBSC) were cultured with U251 and 5310 cells, flow cytometry technology revealed that the cells underwent G1 arrest showing an increase in the G0-G1/S phase ratio. There was also a 54% reduction in levels of cyclin D1 when hUCBSC was cultured with U251 in comparison to the control. Immunoprecipiation revealed that hUCBSC treated cells when immuno blotted with Cdk 4 and Cdk 6 antibodies, down regulated expression of both Cdk 4 and Cdk 6. Western blot also showed the same down regulating pattern of the individual expression and genes which confirmed that there was cell cycle arrest, thus preventing tumours from forming.

As such, this study helps researchers to grasp the foundation of using hUCBSC as a treatment for glioblastoma and to further build on such research. Since it is evident that hUCBSC is effective in reducing cyclin D1 expression; analysing glioblastomal hierarchy will aid in providing the missing links needed to create the clinical treatment.


2. There are a number of developmental vascular "shunts" present in the embryo, that are closed postnatally. Identify these shunts and their anatomical location.

Three major vascular shunts include:

Ductus venosus - is a shunt of oxygenated blood from umbilical vein to IVC, bypassing the liver. The ductus venosus constricts and closes soon after birth and becomes the ligamentum venosum

Foramen ovale - is a flap valve in the atrial septum between the right and left atrium that shunts highly oxygenated blood . The remnant of the foramen ovale is known as the fossa ovalis.

Ductus arteriosus - is a shunt from the descending aorta to the left pulmonary artery near the bifurcation of the pulmonary trunk. Permanent closure takes 4-6 weeks by fibrosis, and the remnant is referred to as the ligamentum arteriosum.

--Mark Hill Good (4/5)

Lab 5

Select an abnormality of either gastrointestinal or respiratory development and write a brief description of developmental causes(s) for this abnormality. Your answer should be added to your own student page, be brief (2-3 paragraphs) and referenced.

Midgut volvulus

The embryonic development of the midgut has a number of steps which ensures its proper formation. These include the viability of the superior mesenteric artery to divide the midgut into the cephalad (pre-arterial region) and caudad (post-arterial region). [1]During the fourth gestational week, the gastrointestinal system is composed of a centrally positioned linear tube in the abdomen. At approximately 6 weeks of gestational age, the midgut undergoes a process of U-shaped herniation causing the two portions of the midguts to face the opposite directions in relation to the superior mesenteric artery. From this moment, a number of rotation events occur to ensure the complete development of the gastrointestinal tract as it becomes set in the posterior abdominal wall.[2]

In some cases malrotations can occur during the developmental process of the midgut which involves the complete twisting of the midgut in relation to the axis of the superior mesenteric artery. In extreme cases this can lead to midgut volvulus which results in a narrowed mesenteric base that can obstruct the passage of blood and lead to tissue necrosis. Other complications resulting from midgut volvulus include intestinal ischaemia, peritonitis, mucosal necrosis and sepsis which can eventually lead to death if left untreated. [3]

Malrotation is known to occur within 1 in 500 live births and out of those who develop midgut volvusos, 68-71% are neonates. [4]Although the actual cause of malrotation is unknown, researchers have made links to congenital syndromes such as Down syndrome and the VACTERL. It is also hypothesized that any embryonic interference during the normal patterns of rotation and fetal development can lead to midgut volvulus. Treatment of midgut volvulus is dependent on when the disease is diagnosed. [5]Normally a sigmoidoscopy is carried out as well as the Ladd procedure to resect dead gastrointestinal tissues. Transduodenal bands of ladd may also be divided to widen the mesenteric pedicle and prevent obstruction of blood flow. [6]Overall, research is still being conducted on the specific causes of malrotation and other numerous treatments.

  1. <pubmed>15378215</pubmed>
  2. <pubmed>7277164</pubmed>
  3. <pubmed>14655161</pubmed>
  4. <pubmed>22217896</pubmed>
  5. <pubmed>18800265</pubmed>
  6. <pubmed>22208840</pubmed>

--Mark Hill Very Good (5/5)

Lab 6

Group work

Lab 7

1.Identify and write a brief description of the findings of a recent research paper on development of one of the endocrine organs covered in today's practical.

Novel genes upregulated when NOTCH signaling is disrupted during hypothalamic development.

It is known that the hypothalamus first develops from the ventral region of the diencephalon and signaling mechanisms such as the sonic hedgehog and bone morphogenic protein pathways are responsible for pattern arrangement. Neurogenesis is the key process required to ensure proper hypothalamus development which relies on many signaling pathways to produce neurons and glia. The Notch signaling pathway is currently known to inhibit neuronal differentiation and preserve neural progenitor identity. As a result of various studies and research, the combined theory has been implemented in this study to determine the effect of downregulating Notch signaling pathways in its effect on hypothalamic development.

Results show that when Notch signaling is inactivated, novel genes such as Dll1, Hes5, Hey1 and Ascl1 are upregulated in the rostral hypothalamus, subsequently leading to the early formation of hypothalamic neurons. This is also seen when embryos that are treated with DAPT (a chemical which inhibits cell differentiation mechanisms regulated by the Notch pathway) had an overexpression of cells differentiated into neurons in a clustered formation. This was compared to the control embryos which had differentiated cells in a scattered arrangement. As such, this research showed that Notch is a powerful signaling mechanism that is used to inhibit cell differentiation in order to control the number of cells differentiated into neurons or glia. This modulating ability of the Notch pathway is imperative in the early developing hypothalamus as it controls expression of cells and hence prevents any form of defects that can be harmful both prenatally and postnatally. Further research needs to be conducted on the Notch pathway to provide procedures where its mechanism can be used to resolve defects in the embryo and hence ensure proper hypothalamic development.


2.Identify the embryonic layers and tissues that contribute to the developing teeth.

Odontoblasts - neural crest-derived mesenchymal cells which establish the outer dental pulp. It differentiates via the enamel epithelium and releases dentin from dentinogenesis.

Ameloblasts - are derived from oral epithelium tissue of ectodermal origin and make up the inner enamel. They make pre-ameloblasts and produce enamel.

Periodontal ligament – is comprised of connective tissues which holds the tooth in place in the alveolar bone. It also encloses the cementum coating of the tooth root.

--Mark Hill Good research article, should give an overview of NOTCH signalling pathway. Tooth summary is good (5/5)

Lab 8

1. Provide a brief time course and overview of embryonic development of either the human testis or ovary. (2-3 paragraphs)

Embryonic development of the ovary

The Gonads are known to be formed from the combination of primitive germ cells, adjacent mesenchyme and the mesothelium of the posterior abdominal wall. It isn’t until fifth week of embryonic development that the formation of Gonads occurs. The primordial germ cells first migrate from the embryonic yolk sac towards the hindgut along the dorsal mesentery. These cells then travel to the mesenchyme forming genital ridges positioned medially to the mesonephros by the sixth week of development. Coelomic epithelium and the mesonephros cells also proliferate at this stage. These cells then incorporate into the primary sex cords in which the process is driven by the genes stella, fragilis, and BMP-4 before the seventh week of embryonic development.[1]

The gonads are known to be indifferent until the sixth embryonic week as the gonads appear the same, however sex differentiation based on sex chromosomes determine the sex of the Gonad (XX for female and XY for males). The indifferent gonads are situated well inside the Wolffian body and are comprised of an inner medulla and outer cortex which contains precursors for ovarian stroma and parenchyma respectively.[2] In embryos consisting of XX sex chromosomes, the cortex of the indifferent gonad differentiates into an ovary meanwhile the medulla regresses by week eight of embryonic development. However, the sex cords leads to the formation of rete ovarii which is a complex of tubules and cords that arises from the mesonephros.

Another important event that occurs during the sixth week of development is the formation of the mullerian ducts which are responsible for female gonad formation and prevention of male gonad development. The established XX genotype of the female embryo prevents testosterone from being produced and hence causes the regression of the mesonephric duct since this form is only needed for male gonad expression. Also since there is no production of anti-mullarian hormone, the paramesonephric duct is able to be maintained driving female gonad expression. As of 10 weeks of development, ovaries first become recognizable and the growth of female external genitalia begins to occur.

Moore: The Developing Human, 9th ed. Chapter 12

  1. <pubmed>23409002</pubmed>
  2. <pubmed>3712511</pubmed>

2.Include an image from the historic genital embryology section of the online notes in your description.


Figure 1. Longitudinal Section of Ovary of Cat Embryo of 9.4 cm long

--Mark Hill Good summary of ovary development both a new and old article, I only wanted the embryonic period covered. (4/5)

Lab 9

Group project 1

The introduction was written quite well as it explains what the respiratory system is about and the origin of its development. It also briefly highlights the difference between the embryonic and fetal stage which is important in enabling the viewers to have an understanding on what the project will be focusing on. I also like how the group distinguished between the two zones of the respiratory tract and adequately described the features and function of each. The content in the lung development stages clearly relates to the topic and underlines fetal development. The group briefly mentioned the key features in each stage instead of pasting a whole lot of information; this makes it easier for viewers to understand. Overall the content relates to the learning objectives of embryology and the level of research is good as exemplified under ‘Current Research and Findings’ and ‘abnormalities’ (many forms of diseases described). The project however could benefit from having a ‘Glossary’ list so that viewers can understand some uncommon words.

The images under introduction and the image used for Meconium aspiration syndrome have not been referenced properly as there is missing information such as ((Template: Student Image)), description, copyright information and proper references for some. The image used under the ‘current research and findings’ subheading is a good example for the group to copy the referencing style. It is also vital that the group adds a brief description of what the image illustrates as a caption to help viewers understand the relation of the content and image (this is seen in the image under ‘surfactant’). More images could be added such as in the ‘lung development stage’ and under abnormalities. If images for lung development stages aren’t easily accessible, it is perhaps a good idea to draw them. The table format used for ‘lung development stages’ makes it easy for the viewers to navigate which is a good feature used in the project.

In terms of referencing, there are many in-cite references missing such as in the ‘introduction’ and in ‘lung development stages’. It is important to have these references formatted correctly under the one ‘references’ subheading. There seems to be many ‘references’ subheadings making it harder for viewers to navigate. Some references are shown as ‘ which needs to be fixed right away. Overall, the content seems well written, formatted and concise making it easy to understand. However the problems related to referencing needs to be corrected as this is inconsistent throughout the project. Group project 2 The introduction is well addressed as it sufficiently describes what the renal system is about and its function. Not to mention its anatomical structure as well as the difference between the embryonic and fetal stages of development. This differentiation enables viewers to understand what the content will be focused on, which is fetal development. Also, it helps focus the viewer’s attention on how the project will be divided as the group mentions abnormalities in the last paragraph. Overall the introduction has the right amount of information from each subheading and is very easy to comprehend. There isn’t any information under ‘historic findings’. If there are any difficulties in finding some historic findings, members of the group can go to pubmed and on the side will be dates such as 1920 that could contain key historical events when renal is entered on search. The use of a development timeline was great as they outlined the major events that occur in a concise manner. Although, I believe a glossary is needed for words like ‘metanephros’ since the viewers would not know what that is. The content under current research models is interesting and correctly describes what the studies were about. Overall, the content used in the project was relating to the topic (fetal development of the kidney) and clearly showed extensive research. I really like how the group divided the different parts of the renal system as well as describing their anatomical positions. The abnormalities listed are also interesting and very easy to understand. I’m hoping to see information under the Horseshoe kidney disease. In terms of images, there should be an image under introduction perhaps having all features of the renal system. Most images are missing the ‘student template’ aspect of the referencing and needs to be added right away. Other aspects such as description, copyright and referencing were correct. I also like the use of captions to describe what the images are about, however some are missing on the page such as the one under ‘anatomical position’ and ‘urethra’. The image used for the ‘development of the kidney’ should be removed from the page as it isn’t permissible. It should be replaced with an image relating to the content and have all the correct copyright and referencing information. Overall, I like the number of images used and its significance to the renal system. They accurately relate to the content of the project. There is use of in-cite referencing which is good, however some references are just listed and should be placed under the proper ‘references’ subheading such as the ones under ‘ureter’ and ‘renal agenesis’. Some references in the ‘references’ list are used over again and can be fixed by combining it under one reference number. To make the project even more appealing, the group could format the information under ‘developmental timeline’ or even ’historic findings’ in a table. Overall, I think this project is great and by making edits based on the peer-reviews received could enhance their project. Group project 3 The introduction is good as it accurately describes what the GIT system is about and the anatomical positions of the features in this system. It also briefly highlights the development stages at embryonic and fetal stages, however ‘embryonic development’ should be mentioned in a little more detail to understand how far in development the fetal stage begins. I also think the introduction should include a sentence or two describing how abnormalities in such organs can lead to these diseases. Basically a bit from each major subheading should be incorporated including current research as an introduction is a summary of the whole page. As for the ‘timeline’, it would’ve been more appropriate to place the timelines under each section, e.g foregut timeline under the ‘foregut’ subheading. This is because viewers would be confused on why there is so much difference in development in one section of the page. A glossary list should be incorporated in a separate subheading to define some of these words such as hematopoiesis so that viewers can fully grasp the information. The information under recent findings is quite interesting and relatable to the content which is GIT fetal development. However, I believe more findings could be incorporated under this subheading. The information under each organ of the three ‘guts’ are quite detailed in fetal development which is good and shouldn’t be too difficult for the viewers to understand. However, I believe the group could include information on the function of these organs as well. The structure of the information under ‘guts’ does not flow in the sense that the midgut includes features and structure whereas the other ‘guts’ do not. The innvervation and bloody supply of the hindgut should be incorporated in a paragraph instead of being listed like that. All the deformities should be places under one subheading to make it easier for viewers to navigate. The abnormalities were also concise and related to the topic. Overall, the content is relating to the topic of the project and addresses key points. It also shows good amount of research, however there seems to be too much information in some parts which could be reduced a bit. The project needs a coherent flow of the structure. As for images, there needs to be an image under introduction which includes all features of the GIT tract. There are a lot of potential images missing under each subheading except for the ‘midgut’ section. This shows that there has been one person working on this section or one section being focused on in comparison the others. The information used to reference the images is missing in some images such as the ‘Human- fetal week 10 sagittal plane D.jpg’ (although this is uploaded from a different user so this is understandable. However images such a ‘GIT 2.jpg’ need more information including ‘student template’ as well as the reference where the image idea may have come from. Also, if this is a hand-drawn image then please state this as one member did in ‘Week 11 midgut herniation.png’. Overall, I enjoy the use of self-drawn images as it makes it easier to show what the content is saying without going through the stress of looking for an image online that doesn’t relate to the content. However more images definitely need to be added. The use of captions is also good and indicates what the images are showing. There are sections where incite referencing are used, however some sections are void of them such as the ‘introduction’ and ‘Liver, Gallbladder and Bile Duct’ (the [6],[7] should be placed next to the text not above the text. The use of a ‘references’ subheading is good the same references have been combined into one number showing that the group knows how to make the references set out. The use of a table in formatting the ‘Percentage of Foetuses Herniated’ is great and shows more that the group has done research. Overall, this is a good project and if the group makes edits based on the peer-reviews received, this could enhance their project. Group project 4 The project doesn’t have an introduction yet; however information such as what the genital system is about, the features of the system as well as the difference between the embryonic and fetal stages of development should be mentioned. Not to mention a brief summary of each key subheading such as abnormalities under introduction e.g. any deformations in the fetal stages of genital development can result in to such and such abnormalities which will be addressed. This will help the viewer’s understand what the project will be going through. As for system development, I can see how there is dot-point description above the table which summarises the same thing. This structure is a bit confusing for me. I believe if the information was summarised into paragraphs and then tabulated it would make more sense. It’s best to format all that information into that table. The use of a table is a great way for the viewers to differentiate between the two sexes and understand the information more easily. I hope to see the table filled out completely soon. A glossary subheading should also be placed on the project page and have keywords defined to make viewers completely understand the content. As for current findings, the information again is in dot points which should be paragraphed instead. However, the current findings are indeed interesting and the right amount of information is used to describe them in both sexes. The content under historic findings such as the ‘female genital development’ doesn’t show any historical events. There are no dates which show when something related was discovered. The ‘male genital development’ however shows dates and discoveries. In my opinion, if this information were tabulated rather than paragraphed, it’d be easier for viewers to navigate and understand. There is a good amount of detail under the abnormalities which relates to the key topic and is easy to understand. Overall, the content is relatable to the genital development of the fetus and underlines all the keys points. However, if this information were paragraphed in some areas and mentioned above, it would make the content easier to navigate and comprehend. In terms of images, there are many places where images are missing such as introduction, system development and current models. I believe there needs to be more images on this page that relate to the content to make it more appealing and understandable to the viewers. The image called ‘File:Flow Diagram of Fetal Development of External Genitalia.pptx’ isn’t permissible and needs to be removed. The use of a hand drawn image on the testes is great, however there is information missing on referencing, student template and copyright laws. On the other hand, there are some images which correctly follow the uploading picture procedures such as the image on the ‘abnormalities of the vagina’; group members should follow this procedure. Captions should be added to each image to address what the images are showing. There are sections where incite referencing are used, however some sections are void of them such as the ‘introduction’ and ‘system development’. The use of a ‘references’ subheading is good, the same references have been combined into one number showing that the group knows how to make the references set out. However reference 20 and 21 are the same, please fix this. Also there are references under each subheading which should be placed all under one ‘references’ subheading. Overall, this is a good project and if the group makes edits based on the peer-reviews received, this could enhance their project. Group project 5 The introduction is a great summary of what the project page will discuss making sure to highlight every aspect. However, the introduction should also mention more about the integumentary system listing all the organs involved, their function, anatomical position and the difference between the embryonic and fetal stages of integumentary development. The content presented on the page is fantastic. All information under the subheadings looks complete and has key information related to the topic. I like how the timeline is divided into each organ making it easy to understand and navigate. The use of the table to format the information is a brilliant idea and has been presented beautifully with images in each textbox. Also the content under current research is relating to the topic and shows extensive research. The use of the purple background is appealing to the viewer highlighting its significance. I do however believe that the information under ‘historic findings’ should be formatted into a table to make it easier to navigate. The content under ‘abnormalities’ has the right amount of information and clearly relates to the key topic of the project. In terms of images, I believe a satisfactory amount of images have been used which clearly describes the content. However, some images are missing the all the copyright information needed as well as the description, references and student template such as those in the ‘development overview’ table. This should be added right away to ensure these images do not get deleted. The use of captions on these pictures is important to highlight what the image is referring to and this is present in the page. Although, images could be added under current research as this section looks like it could use more images. Great job on the images under abnormalities, they accurately relate to the content mentioned. There are some incite references missing such as in the development overview. I’m not sure if the references listed below are supposed to the references for it, however all references should be placed under one ‘references’ subheading. The same references have been combined into one number showing that the group knows how to make the references set out. Also a glossary list should be added to help viewers understand the content more instead of just being confused at some sections. Overall, this is a great project and if the group makes edits based on the peer-reviews received, this could enhance their project. Group project 7 The introduction is great as it mentions the features of the neural system, their anatomical positions and highlights the key events in the embryonic and fetal stages of development. The last paragraph of the introduction clearly addresses how the page will be divided and what the viewers are to expect which is good. The content under all subheadings are relating to the key topic and are formatted appropriately. I really like the image used under the subheading ‘Development during fetal period’ as it presents a diagrammatic representation of the content mentioned. The use of a table to briefly describe the events that occur at certain periods of fetal development is really helpful in grasping the main details. Some information is missing such as in ‘spinal cord development’, ‘Meninges development’, ‘future research’ and some ‘abnormalities’. This should be added right away. There are no historic findings which is great to have on your page for viewer’s fascination into the group project. Members could search on pubmed about the neural system and view dates on the side that may contain key findings. Also a glossary list should be added to help viewers understand the content more instead of just being confused at some sections. In terms of images, there are still many potential spaces for images such as under ‘introduction’, ‘current research’ and some ‘abnormalities’. The images used under ‘Development during fetal period’ are great and relate to the content. All images have correct description, referencing, copyright issues and ‘student template’, which shows that members of the group have followed correct ‘uploading image’ procedures. The images however need a caption to describe what the image is showing. There needs to be more use of incite referencing such as in the ‘introduction’, ‘brain development’ and ‘abnormalities’. There is a huge list of references under ‘current research models and findings’ which need to be placed all under one ‘references subheading’; similarly to any other reference list on the page. References 7 and 8 are the same reference under the ‘references’ subheading and need to be combined into one number. Overall, this is a good project and if the group makes edits based on the peer-reviews received, this could enhance their project. Group project 8 The project doesn’t have an introduction yet; however information such as what the Musculoskeletal system is about, the features of the system as well as the difference between the embryonic and fetal stages of development should be mentioned. Not to mention a brief summary of each key subheading such as abnormalities under introduction e.g. any deformations in the fetal stages of musculoskeletal development can result in to such and such abnormalities which will be addressed. This will help the viewer’s understand what the project will be going through. I like the ‘making gains’ subheading as it adds humour to the page and engages the viewers. The general timeline needs information including what events take place at certain phases of fetal development. This could be present in a table to make the information more clear. It’s good that the project has information on the embryonic development so that the viewers can understand how the fetus arises to that point in development (fetal period). All of the content seems to relate to the key topic and is appropriately paragraphed. However much of the content is still missing such as in ‘recent findings’ and ‘introduction’. More information could be added under the associated ‘trimesters’ and ‘abnormalities’. There are no historic findings which is great to have on your page for viewer’s fascination into the group project. Members could search on pubmed about the musculoskeletal system and view dates on the side that may contain key findings for historical events. Also a glossary list should be added to help viewers understand the content more instead of just being confused at some sections. There are no images on this page and definitely needs to be added with the appropriate information such as the description, referencing, copyright issues and ‘student template’. If images are not readily available, it is best to draw them. Also captions should be added on the page to state what the images are showing. As for referencing, there are some sections which shows incite referencing such as in the content under ‘Molecular and Cellular regulation of fetal myogenesis’ and some that don’t have any like in ‘tendon development’. There needs to be references in all sections. There is a huge list of references under ‘abnormalities’ which need to be placed all under one ‘references subheading’; similarly to any other reference list on the page. Number 15 of the reference list has an error in it and needs to be fixed right away. Overall, this is a working progress and if the group makes edits based on the peer-reviews received, this could enhance their project. --Mark Hill Very good peer feedback (10/10)

Lab 10

Identify a recent research paper on sensory development (not hearing) and write a brief summary (several paragraphs) of the research methods and findings. Include at the end a link to the relevant wiki sensory notes page.

TSHZ1-dependent gene regulation is essential for olfactory bulb development and olfaction.

A major feature of the olfactory region is the olfactory bulb which contains mitral cells that serve to relay olfactory messages via sensory neurons of the olfactory epithelium to the piriform cortex of the brain. Within the granular cells and glomerular layers are interneurons which control the message output via synaptic linkages between mitral and tufted cell projection neurons. These interneurons continue to grow postnatally via neural stem cells located in the dorsolateral ganglionic eminence (dLGE) which consists of the subventricular zone and subependymal zone. When neuroblasts migrate to the dLGE, this stimulates dLGE-derived interneuron progenitors to migrate radially in the growing bulbs where they mature into the granular or glomerular cell layer. There has been research showing how teashirt zinc finger family member 1 (TSHZ1) is vital for the development of the olfactory bulb. In mice, it was found that olfactory bulb neuroblast differentiation required Tshz1 expression or else a large proportion of interneurons of the granular cell layer will not be present and radial migration of neuroblasts will be impaired. The basis of the previous studies was then replicated in humans suffering from congenital aural atresia that had TSHZ1 loss-of-function mutations.

Coronal sections 500-μm in size was obtained from the subjects which then underwent Nissl staining with cholineacetyl transferase histochemistry to observe the change in patterns of normal and abnormal olfactory development. In some parts of the experiment, mice were used as subjects to observe how congenital aural atresia may also affect them. In situ hybridization was used to investigate this effect on mice whereby Tshz1 positive and negative gene transcripts were obtained and amplified using polymerase chain reaction (PCR). Primers of the targeted gene and splicing enzymes were used to make sure the correct transcripts were produced.

Through immunoflourenscing and immunohistology, it was found that Tshz1 mutation lead to an abnormal distribution and differentiation of granule cell neurons of the developing olfactory bulb. Green fluoresce protein was integrated in the Tshz1 locus in both Tshz1+ and Tshz1- subjects. Through immunostaining of olfactory bulbs, it was shown that there was a consistent outer granule cell ring distribution of GFP+ cells in comparison to the unevenly distributed GFP+ cell located in the inner granule cell layer. DAPI staining revealed that the structure of the olfactory bulb in Tshz1 positive subjects were more layered and structure compared to deformed structure seen in Tshz1 mutants. The granule cell and external plexiform layers were indistinguishable and the glomerular layer had multilayers, thereby showing the abnormality in Tshz1 mutants.

Microarray hybridization was used to sort out gene expression in Tshz1 positive and negative subjects. Out of all the gene transcripts profiled, it was noted that the most significantly changed transcripts was Prokr2. Expression of PK2 was also downregulated in the rostral migratory stream of the subjects. Prokr2 expression was therefore examined in the developing olfactory bulb of Tshz1 positive and mutant mice using in situ hybridization. It was found that Tshz1 mRNA expression was seen in both the outer granule cell layer and the inner layers of the olfactory bulb mainly consisting of immature cells. Prokr2 expression was observed only in the inner layers of the OB in Tshz1 positive subjects and in mutants, Prokr2 expression was greatly downregulated. Overall, it was established that Tshz1 is needed to control the expression of Prokr2 which radially migrates neuroblasts. In addition, the PK2 family and its associated receptor are imperative factors required for normal olfactory bulb development.


Wiki link:

--Mark Hill Very good (5/5)

Lab 11

Identify a recent research article (using the pubmed tags to cite) on iPS cells and summarise in a few paragraphs the main findings of the paper.

Human iPS cell-engineered cardiac tissue sheets with cardiomyocytes and vascular cells for cardiac regeneration.

As cardiovascular disease continues to be the number one cause of death in the older population, there is significant research based on using stem cells as a tool to regenerate functional and healthy cardiomyctes in patients who’ve suffered from myocardial infarction. In particular, human induced pluripotent stem cells (hiPSCs) are used in this study to observe how these cells can generate cardiovascular cell sheets that may be used to treat infarcted heart tissue. Not to mention how hiPSCs may overcome obstacles such as poor engraftment of the cells injected in the heat and immunorejection, thereby placing the research more towards clinical practice.

Main findings

Data obtained from the study showed that there was simultaneous induction of cardiomyocytes and vascular cells using human IPSCs. It was shown that the levels of gene expression of cardiac mesoderm/progenitor genes (KDR/ISL1) were heightened on the day they were due to differentiate and when Dkk1 (a canonical Wnt antagonist) was added, the rate of differentiation of cardiomyocytes from mesoderm cells was increased. However when VEGF was added, this stimulated the induction of cardiomyocytes and vascular cells at the same time.

Furthermore, it was discovered that hiPSCs could generate cardiovascular cell sheets by placing hiPSC-derived cardiovascular cells into 12-multiwell temperature-responsive culture plates. After reducing the temperature, it was found that self-pulsating cell sheets (hiPSC-CTSs) was comprised of 3-4 cell layers with complete stratified structure of collagen positioned adjacent to the cell constituents. Immunostaining revealed that cardiomyocytes were expressed in large numbers out of all the three cells (myocytes and vascular endothelial cells), suggesting that non-myocytes are needed in cell sheet formation by remodelling cardiac cell distribution.

hiPSc-CTs were also shown to improve cardiac function after acute myocardial infarction in rats. The hiPSc-CTs were lined up in a 3-sheet structure where they were transplanted into a rat with acute myocardial infarction. After 8 weeks, an echocardiogram was performed and showed that anterior wall contraction was restored and parameters for left ventricle (LV) systolic function, fractional shortening (FS) and fractional area change (FAC) were improved. Sirius red staining also indicated that hiPSC-CTS transplantation greatly prevented fibrosis, thereby leaving more cardiac tissues to function properly.

Overall, this study shows evidence that HiPSC-CTSs are showing promising results in the generation of cardiomyocytes and in restoring cardiac function of those that suffered from myocardial infarction.


  1. <pubmed>25336194</pubmed>

--Mark Hill Very good (5/5)