User:Z3418981

From Embryology

Lab Attendance

Lab 1 --Z3418981 (talk) 12:45, 6 August 2014 (EST) http://www.ncbi.nlm.nih.gov/pubmed PubMed PMID25084016 <pubmed>25084016</pubmed> Lab 2 --Z3418981 (talk) 12:17, 13 August 2014 (EST) Lab 3--Z3418981 (talk) 12:58, 20 August 2014 (EST) Lab 4--Z3418981 (talk) 11:48, 27 August 2014 (EST) Lab 5--Z3418981 (talk) 11:42, 3 September 2014 (EST) Lab 6--Z3418981 (talk) 11:51, 10 September 2014 (EST) Lab 7--Z3418981 (talk) 11:17, 17 September 2014 (EST) Lab 8--Z3418981 (talk) 12:30, 24 September 2014 (EST) Lab 9--Z3418981 (talk) 12:22, 8 October 2014 (EST) Lab 10--Z3418981 (talk) 12:11, 15 October 2014 (EST) Lab 11--Z3418981 (talk) 12:18, 22 October 2014 (EST) Lab 12--Z3418981 (talk) 11:39, 29 October 2014 (EST)

Individual Assessments

Lab 1 Assessment

Reference: PMID24726222

<pubmed>24726222</pubmed>

Summary of the Method

In this study, genomic DNA was extracted from the umbilical cord blood of a total of 185 newborn females. Patients included 60 infants conceived by intracytoplasmic sperm injection (ICSI) and 73 infants conceived by in vitro fertilization (IVF) all recruited from a number of IVF centers across Canada. In addition, 52 naturally conceived patients were recruited from hospitals across the Lower Mainland in British Columbia, Canada. A karyotype or comparative genomic hybridization (CGH) analysis of the chromosomes was performed for all newborn cases. Cases were not included if congenital and/or chromosome abnormalities were present.

The X-chromosome inactivation (XCI) assay was performed to determine the XCI skewing of different tissues in different parts of the placenta by assaying allelic ratio of methylated alleles at the androgen receptor(AR), fragile X mental retardation 1 (FMR1), and DXS6673E loci. Fisher's exact test was a statistical method used to compare the frequency of mildly skewed (≥75%) and extremely skewed (≥90%) XCI in the patients. The parental nature of the skewed allele was determined by automated fluorescence analysis which was used to measure the AR alleles of the maternal decidua of the placenta.

Summary of the Results

There was no statistically significant difference between the ICSI, IVF and NC populations in the frequency of skewing ≥75% (7.0% vs. 5.7% vs. 2.0%, respectively; P=.523) or ≥ 90% (0 vs. 1.4% vs. 2.0%, respectively; P=.747). The mean level of skewing between the ICSI, IVF, and ICSI groups also was not significantly different (63.7% vs. 61.8% vs. 60.7%, respectively). Only two samples were found to have extremely skewed cases (≥90% skewing): one IVF (89.6%) and one NC (90.6%). The parental origin of the preferentially inactivated X chromosome in these extremely skewed cases was maternal for IVF and paternal for NC case.


Reference: PMID24399508

<pubmed>24399508</pubmed>

Summary of the Method

All of the pregnancies conceived by in vitro fertilization in Denmark from 1995 to 2005 (n = 18 787) was included in this study using the data reported to the National In Vitro Fertilisation register (IVF register). Information about the pregnancy outcomes as well as cycle-specific information on the type and date of treatment, and the occurrence of pregnancy, abortions and deliveries was also obtained from IVF.

A study published by Virkus et al. on venous thromboembolism in pregnant and puerperal women in Denmark was used as a reference (Virkus et al., 2011). This study was used as a reference since the population used in this study (727 VTE patients among the 805 464 pregnancies recorded in the Danish National Patient Registry from 1995 to 2005) is ideal and comparable to the present study. Consequently, venous thrombosis incidence rates in pregnancies conceived by in vitro fertilization were compared with venous thrombosis incidence rates in reference pregnancies, by calculating incidence rate ratios.

Summary of the Results

The venous thrombosis incidence was significantly increased in pregnancies after in vitro fertilization. The overall ratio of venous thrombosis incidence rate during in vitro fertilization pregnancies to reference pregnancies was 3.0 (95% CI 2.1–4.3). The overall venous thrombosis incidence rate was 28.6 per 10 000 pregnancy-years (95% confidence interval (CI) 20.6–39.6) for pregnancies after in vitro fertilization compared to 10.7 per 10 000 woman-years in reference pregnancies.

Reference used in the "Summary of the Method" section:

<pubmed>21713323</pubmed>

--Mark Hill These articles are well summarised and relevant. Please do not use all capitals in sub-headings and follow the site formatting. (5/5)

Lab 2 Assessment

An overview of the process of fertilisation in mutant C. elegans.jpeg

Image showing the process of fertilisation in mutant C. elegans[1]

--Mark Hill (talk) 16:19, 21 August 2014 (EST) This is all correct. The image is very large (1.15 MB), perhaps a smaller image version could have been uploaded. You can adjust the resolution and size in most image editing programs. (5/5)

  1. <pubmed>15086962</pubmed>|BMC Developmental Biology

Lab 3 Assessment

Abnormalities associated with neural development

<pubmed>12454899</pubmed> <pubmed>25007063</pubmed> <pubmed>16530991</pubmed> <pubmed>7504639</pubmed> <pubmed>19651588</pubmed> <pubmed>25135350</pubmed> <pubmed>25128525</pubmed> <pubmed>24397701</pubmed>

--Mark Hill These are all relevant references, and a sentence description for selection would also help. (4/5)

Lab 4 Assessment

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


<pubmed>24104453</pubmed>

The inhibitory effect of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on the growth of C6 glioma cells was investigated in this study. Initially C6 cells were cultured with different concentrations of hUC-MSCs in order to examine whether the hUC-MSCs inhibition of glioma cell growth was mediated by soluble factors. It was found that hUCMSCs-CM exhibited a concentration-dependent inhibitory effect on C6 cell growth which in turn suggested that soluble factors in the conditioned media from hUC-MSCs were responsible for the inhibition of C6 glioma cells. Subsequently, flow cytometric analysis was used to test the effect of the soluble factors derived from hUCMSCs-CM on the cell cycle of glioma cells. Using this method, cell cycle status of C6 cells treated with different concentrations of hUCMSCs-CM was identified. It was observed that C6 cells treated with hUCMSCs-CM showed increases in the G0/G1 phase and reductions in the S phase compared to the control group (0 % hUCMSCs). These results suggested that hUC-MSCs could potentially inhibit the growth of C6 glioma cells and stop the cell cycle at the G0/G1 phase by secreting some soluble factors.

Western blot analysis was then performed and it was observed that the expression levels of β-catenin and c-Myc in C6 cells were reduced in the conditioned media derived from hUC-MSCs. These results indicated that some soluble factors secreted from hUCMSCs-CM may play a role in the inhibition of Wnt signaling pathway in C6 cells. Further investigations demonstrated that the secretion levels of dickkopf-1 (DKK1) were positively correlated with the concentrations of hUCMSCs-CM. Subsequently, the hypothesis that stem cells secreted Wnt inhibitors, such as DKK1, which could inhibit the Wnt signaling in tumor cells, was made.

Neutralizing antibody against DKK1 was then added to the hUCMSCs-CM in order to further confirm that DKK1 is a key factor in the inhibitory effect of hUCMSCs on C6 cell proliferation. It was observed that the inhibitory effect of hUC-MSCs on C6 cells was decreased when DKK1 was neutralized by anti-DKK1 antibody. Moreover, it was found that conditioned media from hUC-MSCs transfection with siRNA targeting DKK1 mRNA altered the regulation of the Wnt signaling in C6 cells. Therefore, it was concluded that hUC-MSCs inhibited C6 glioma cell growth by secreting DKK1, an inhibitor of Wnt pathway.


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


There are three developmental vascular "shunts" present in the embryo that are closed postnatally:

Foramen ovale (Foramen Botalli)

Foramen ovale is an opening in the inter-atrial septum which allows blood from the right atrium to enter the left atrium during foetal development. Foramen ovale allows blood to bypass the non-functional foetal lungs while the foetus obtains its oxygen from the placenta. A layer of cells exist over the foramen ovale during fetal development which acts as a valve and is known as septum primum. After birth, increased pulmonary blood flow and pulmonary venous return to left heart causes the pressure in the left atrium to be higher than the pressure in the right atrium. The increased left atrial pressure results in the closure of foramen ovale after birth.

Ductus venosus

In the foetus, the ductus venosus shunts blood from the left umbilical vein directly to the inferior vena cava and therefore allows oxygenated blood from the placenta to bypass the liver. Ductus venosus plays an important role in shunting oxygenated blood to the fetal brain.The ligamentum venosum which is usually attached to the left branch of the portal vein is the fibrous remnant of the ductus venosus

Ductus arteriosus (Ductus Botalli)

Ductus arteriosus connects the pulmonary artery to the proximal descending aorta. Ductus arteriosus prevents the output of the right ventricle from entering the unexpanded, fluid-filled and non-functional foetal lung. Therefore only enough blood reaches the foetal lungs to maintain the developing lung tissue. Ductus arteriosus becomes the ligamentum arteriosum after closing at birth.

--Mark Hill Good paper review all shunts correct (5/5)

Lab 5 Assessment

Azygos Lobe

Azygos lobe (also known as Adam's lobe) is a congenital malformation of the lung due to an alteration in the embryonic development of the azygos vein. Azygos lobe is a common congenital anomaly with an incidence of 1 in 100-200 of anatomical samples and 0.4-0.5% of chest radiographs. In general, azygos lobe means accessory lobe or supernumerary lobe of lung. There are three main types of azygos lobes: upper azygos lobe, lower azygos lobe and the lobe of azygos vein. The upper and lower azygos lobes are of very little clinical significance compared to the lobe of azygos vein.

During normal fetal development, the right posterior cardinal vein (precursor of the thoracic segment of the azygos vein) migrates over the apex of the right upper lung to occupy a medial mediastinal position. In the case of azygos lobe, an abnormal migration of this vein occurs and it penetrates into the right upper lobe. The right posterior cardinal vein carries the parietal and visceral layers of pleura with it and forms an accessory fissure made up of a total of four pleural layers called mesoazygos. The lung parenchyma located medial to the accessory fissure is called the azygos lobe.

Subsequently in the case of azygos lobe, the abnormal azygos vein crosses the apex of lung instead of its border and forms a fissure which separates the apex of the lung into medial and lateral parts. The medial part of the ruptured apex forms the lobe of azygos vein. Therefore the azygos lobe is a variably separated portion of the right lung and not an independent segment. Moreover, some course variability of the phrenic nerve have also been observed in the presence of an azygos lobe which is of importance when performing surgery.



References

<pubmed>16333920</pubmed> <pubmed>23705047</pubmed>


Lab 7 Assessment

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.

<pubmed>14561778 </pubmed>

In this study, the functional characterization of Arx, a gene encoding homeodomain-containing proteins that are potentially involved in endocrine pancreas development is being investigated. To study the role of this gene in pancreas development, loss-of-function mutant mice were generated by targeting the genes in mice embryonic stem cells. Arx-deficient mice developed severe and early-onset hypoglycaemia, dehydration and weakness and died only two days after birth. Immunohistochemical analysis of Arx mutant pancreas then revealed an absence of mature endocrine α cells and an increased number of β and δ cells. However, islet morphology and the total number of endocrine cells remained intact. These results suggested a requirement of Arx transcription factor for α-cell fate acquirement and a repressive action on β-and δ-cell destiny, which is exactly the opposite of the phenotype observed in Pax4-deficient mice.

Therefore, the results of this study suggest that a mutual cross-regulatory inhibition of these factors exist so that Arx promotes α-cell cycle and prevents β- and δ-cell proliferation whereas Pax4 favours β- and δ-cell fate and inhibits α-cell proliferation. It was demonstrated using multiplex reverse transcriptase PCR (RT-PCR) that Pax4 and Arx transcripts accumulate in Arx and Pax4 mutant mice, respectively. These results further suggest that the antagonistic functions of Arx and Pax4 for proper islet cell specification are based on the pancreatic levels of the respective transcripts.

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

a) Neural-crest-derived mesenchymal cells that differentiate under the influence of the enamel epithelium form odontoblasts. Odontoblasts secrete predentin which calcifies to form dentin.

b) Epithelial cells give rise to ameloblasts that produce the enamel of the tooth.

c) Periodontal ligament is a special connective tissue structure that holds the tooth in place and surrounds the tooth root coating of cementum.

--Mark Hill correct (5/5)

Lab 8 Assessment

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

Embryonic Development of Ovaries

The gonads are developed from mesothelium lining the posterior abdominal wall, underlying mesenchyme and primordial germ cells. The initial stages of gonadal development are the same in males and females and occur during the fifth week with the formation of the gonadal ridge, a bulge on the medial side of the mesonephros. Finger like epithelial cords then grow into the underlying mesenchyme forming the gonadal cords. In females (XX), the cortex of the indifferent gonad differentiates into an ovary, and the medulla regresses.

Primordial germ cells are the first population of cells that migrate through the primitive streak in early gastrulation. These cells then lie at the hindgut yolk sac junctional region and subsequently migrate into the gonadal ridge in early embryonic development. The primordial germ cells enter the underlying mesenchyme during week 6 and are incorporated in the gonadal cords.

The gonads of males and females are identical before week 7 and are called indifferent gonads. Germ cells migrate into the indifferent gonads. The ovaries (females, XX) or testis (males, XY) then begin to develop and the successive structure of germ cells differentiates for each of the two sexes. In females with XX, genes on X-chromosome (such as Wnt-4 and DAX-1) along with an autosomal gene are necessary for initiation of female pathway. Ovary development is a slow process in female embryos and the ovary is not histologically identifiable until week 10.

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

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

Bailey330.jpg

Image showing a section through the ovary of a human foetus of 4 months.

--Mark Hill Ovary summary is correct, I do not like the textbook to be used as a reference source. (4/5)

Lab 9 Assessment

Group 1 (Respiratory System)

The introduction is written well and it provides sufficient background information on the anatomy and development of respiratory system. It is also well-divided into the two conducting and respiratory zones. However it lacks to provide information on what is included in the page such as current research and abnormalities. In addition, this assignment is aimed to describe the fetal development but fetal period does not seem to be the focus in this project. I understand that it is difficult to focus on fetal period, especially for the respiratory system but if that is the case, you can mention why you’re also including information on embryonic and postnatal periods in your introduction. There are also a few spelling errors within the text that should be corrected (such as ‘id’ instead of ‘is’). The images of the histological sections are relevant but there is no caption for any of the photos and it is difficult to understand what they are trying to show. There is no information provided on the summary of the image either and one of the images is missing copyright information. In addition, the text as well as the images in the introduction needs to be referenced on the page. The table of lung development stages is simple and very well summarised. The content of this section relates to the learning objectives of embryology however there is not enough explanation considering that this section is the main part of the project. In order to aid with understanding of the development of lungs, simple diagrams could be drawn that show different developmental stages. You can then explain more on what happens in each stage.

The first paragraph of the current research and findings about the conducting system and functional unit is already discussed in the introduction and therefore there is no need to include it again in this section. Try to include more precise information on the findings of each study and also talk about the new models that have aided in understanding of the development of this system. For example you can elaborate more on the three geometrical models that are proposed in the review study in 2013(there is no information under the “current models” subheading at the moment- you can put this information there). Also it is a good idea to organise the research findings in chronological order so that new advancements are found in more recent studies (2011 must come before 2013).The two alveolar cell types under current research is irrelevant – I would put them under introduction. Also I don’t understand why the image of lung diseases is under current research (maybe put that image under abnormalities?)

The historic findings section is very informative, especially the “surfactant” section. You can also tabulate the data to make it look neater. However from my understanding, in this section we also need to provide information on the history and stages of fetal lung development. I know it is hard to find this information but maybe try looking for review articles that summarise the findings of past studies in this area. The abnormality section is well written and thorough with so many abnormalities named and described. The only suggestion is to include more images.

Overall, this web page shows a very effective team work and it is clear that work has been allocated with each person working on a different subheading. You only need to pay attention to minor issues mentioned above. Also in terms of referencing, there are many in-text references missing in different sections. It is very important to format these references correctly under one ‘references’ subheading at the end of the page (instead of having a separate reference list for each section).

Group 2 (Renal System)

Introduction is very well-written with a precise background on the renal system anatomy and function. There is also a brief introduction on the development of renal system in both embryonic and fetal period as well as the abnormalities that can be associated with the development of this system. Therefore the reader can gain an expectation of what is going to be included in the wiki-page by reading the introduction first. In-cite referencing is also used to support the information provided. I suggest including an image of the anatomy of organs in the renal system to make the introduction even more perfect.

The developmental timeline is a very good way to start the development section; however your timeline is missing some of the important features such as when the ureter and urethra develop. I would also recommend tabulating the data so that it looks neater. I also recommend placing the “current research models” section after the sections describing the development of different organs so that the timeline is located right before the section explaining the development of “kidney”. Dividing the development into different organs and the subheadings used (especially under the heading of “kidney”) are very appropriate and are evidence of significant research that has been done for this project. The information provided is very comprehensive; however it is all formatted in paragraphs. I would suggest using dot points or adding your own diagrams and figures to summarise the text and make it more interesting to the readers. For example the diagram used to illustrate the anatomical position is very helpful and effectively summarises the information to readers. You should also make sure that you remove the image used for the development of kidney since it cannot be used due to copyright. In addition, most images are missing the ‘student template’ so make sure the template is added. There isn’t any information under the heading ‘historic findings’. I understand that this section is a bit more difficult than the rest. A suggestion I can make is to search for old articles in PubMed (by adjusting the year) which can include key historical events. Review articles that summarise historic findings related to renal development may also be helpful.

The content under “current research” is very interesting and relevant. A minor spelling error exists (“buy” instead of “by”). To further improve this section, I suggest searching for recent models that aid in better understanding of kidney development. The abnormalities section is very informative. Each disease is explained thoroughly and concisely. The images are also very helpful with the understanding of clinical manifestations. To improve this section, I suggest using dot-points and using more images. Make sure you include information for “Horseshoe Kidney” as well.

Overall, the content used in this project was very relevant and showed extensive research and understanding. The use of headings and subheadings was very appropriate which showed that the work has been well-divided among members. The use of in-cite referencing is also very good and references are all listed under one subheading; however, some references are used more than once, this can be fixed and they can be all combined under one number.

Group 3 (GIT)

Introduction is good with brief background information on the anatomy of the GIT which is an appropriate starting point for the readers. Fetal development is also described in the introduction, however I suggest including more information on embryonic period and how that leads to fetal development so that the rest of the page can focus more on the fetal stages. I also suggest including parts of each of the major subheadings in the introduction such as the common abnormalities and the recent finding. An image illustrating different organs of GIT can also help with better understanding of the anatomy. There is no referencing in the introduction to support the information provided. Regarding the timeline section, the information needs to be tabulated in order to make it easier to compare between organs. Another alternative is to include a small timeline for each of the organs at the beginning of each section. It is very good that each stage of the timeline has been separately referenced; this shows the extensive research that has been conducted.

The recent finding section focuses on only one study in 2006 on hedge-hog signalling pathway. There are a lot of interesting and more recent studies that can be included in this section. As a starting point, you can search for recent models that help in better understanding of GIT development. The information under each of the foregut, midgut and hindgut is very detailed and comprehensive; however the structure does not flow through the whole page with mid-gut including different subheadings and diagrams. In my opinion you should break up the foregut and hindgut sections into smaller subheadings and use diagrams like the ones used for midgut. Potential images can also be used in these sections. Additionally, the anorectal deformities under the ‘hindgut’ section can be placed under the deformities section. The “Midgut” section includes very good information and the drawings are helpful in understanding the concept however they need to be captioned.

This project does not include historic findings. I understand that this section is a bit more difficult as it is hard to find information on it. A suggestion I can make is to search for old articles in PubMed (by adjusting the year) which can include key historical events. Review articles that summarise historic findings related to GIT development may also be helpful. The abnormalities are precisely discussed and are relevant to the topic but as mentioned before, I suggest putting all the abnormalities under one subheading to make it easier for the viewers to navigate.

Overall, the main key points are addressed in this project and the content demonstrates extensive research and a good understanding of the concept. In order to facilitate learning and to make it more interesting and understandable for viewers, some of the text can be summarised in diagrams. Dot -points can also be used in some parts instead of paragraphs. The use of hand written drawings was creative and aided in understanding however I would suggest stating that the drawing is handwritten in your page. If the drawing is copied from another image, then the source of that image needs to be included as well. Also a more complete description of the image will make it easier to understand.

Group 4 (Genital System)

An introduction is recommended as it is usually a good starting point. I suggest starting by giving background information on the anatomy of male and female genital systems. You can then talk about the embryonic period and give a brief summary of how this period is different to fetal period. You can then briefly mention the significant events that occur during fetal period and the sections you are including in your project (including abnormalities and research findings).

The table in the system development is a good summary however it looks a bit messy at this stage. I suggest having two different tables for male and female, avoid using all capital letters and bold texts in the table. I also suggest starting the development section with a brief paragraph on early stages of development. The image included under ‘system development” is a very good summary but it needs to be captioned and referenced. I also recommend re-uploading the image in a smaller size to improve the quality. The use of the video is also very creative. Well done for finding this helpful video!! It would be perfect if you could reference the video and maybe include a few sentences on what it is showing. Overall, the development section is very good with the use of different methods to help in learning. To make this section perfect, you can add some details in paragraphs to explain more on different stages of development.

There is a lot of information under “current models” which shows extensive research, however I find this section hard to follow. Using paragraphs instead of dot points will result in a more coherent flow. Also the studies need to be referenced appropriately; it would be a good idea to include the name and year of the article in the text. The division into “current research” and “current models” is a smart thing to do however in both sections the amount of information provided for male is much more than female therefore more research needs to be done for female. I like how a self-drawn image is used; it would be a good idea to include a description for the image (rather than “alt text”). Also make sure that all the references are listed at the end under one reference subheading instead of having different references for each section. Also, great job for historic findings! This is the most difficult section but you have managed to include detailed information. Similar to current research section however, most of the information found is for the development of male system. Try to add to historic findings on female system if possible.

Abnormalities section includes a significant number of abnormalities with causes and treatment of each abnormality addressed precisely. I also like how you divided this section into female, male and both. Information is well referenced and helpful images are included. Make sure that your images are referenced. If self-drawn images are used, then you can briefly mention that in your text. I would also recommend adding more images for other diseases to illustrate the clinical manifestations of each disease. Overall this group has done an extensive research and the methods used (such as drawings and videos) are very creative and helpful. Well done!

Group 5 (Integumentary System)

The presentation of this page is very well with multiple images being used and text organised into tables and dot points. The introduction is short however includes necessary information regarding what is being included in the project. I recommend adding background information on anatomy of the skin (explaining on different layers) and other structures as well as a brief summary on the embryonic development of the system so that fetal development can be further expanded throughout the project.

The development overview section is done very well and is divided into different sections each explaining the development of a different structure. The use of table, images and bullet points has made the page look very interesting. The table of the timeline in the ‘Development Overview’ is done very well and the use of histological images is excellent as it helps in visualising the anatomy at each stage. There is however no proper referencing, copyright information or student template for any of the images. The table under “teeth” is also a very good summary of events during fetal period. I recommend including self-drawn diagram as well, since this is the only feature missing from your project. You can include a drawing of the different layers of skin (possibly in the introduction section). I also suggest putting all the references under one reference list at the end of the page instead of having references at the end of each section.

The “some research finding” section is presented well with a different background colour to other sections (it is similar to recent findings in mark’s wiki pages). This makes the page look very visually appealing! You have elaborated on two out of four research papers which is very good. However I recommend describing the other two papers as well and even including more papers (It would be perfect if you could provide research papers for different structures). I like how the “more research papers” can be expanded for anyone interested.

Historic findings section is very well researched considering it is difficult to find information for this section. The ‘Abnormalities’ section is also perfect and complete with all four diseases having sufficient information and appropriate references. The images are also relevant and illustrate the clinical manifestations well. Overall this page is very well-organised and only minor issues mentioned above need to be fixed.

Group 6 (Endocrine System)

The endocrine system is made up of different glands and there is so much information that could be provided regarding the the anatomy and development of each gland so very well done for working on the difficult system! I like how you have divided the page into different glands; I can imagine having the four major headings (development, historic findings, current research and abnormalities) and then subdividing it into different organs would be more confusing. Just try to follow the same structure for each organ; I recommend doing a brief introduction, anatomy, function, timeline, development, historic findings, current research and abnormalities for each organ. It is important that your page has a coherent flow by following the same structure for each subheading. An overall introduction on endocrine system might also be very useful. You can then include in the introduction how you are planning to structure your page.

The content and number of references show that extensive research has been conducted. It would be great if you could use in-text referencing and place all the references under one subheading at the end of the page. Arranging the information into tables is a great idea but you need to complete your tables for pineal gland, hypothalamus and placenta. You also need to include more images in your page (you can include at least one image for the abnormality associated with each organ). There are a few images included at the moment and they are well done and appropriately referenced. You can also try to draw your own diagrams. In my opinion, a timeline showing the development of all the systems would be a great way to compare the different stages in development of different endocrine glands. Maybe think about including this in a table after you finished all the sections; it is a good way to connect the information provided separately for each organ. Overall the content of this page is very good but it needs to be formatted so that it can have a coherent flow. Also there is no information for introduction, historic findings and development of placenta, make sure you include those.

Group 8 (Musculoskeletal System)

In this project the development section is well-researched however introduction, historical findings, current models and abnormalities still need some work. The development section is very informative with appropriate use of in-text referencing. However, to prevent having bulks of text, you can create diagrams and flow charts or use bullet points. It would also be great if you could provide a timeline under “muscle development general timeline” section. Background embryonic development section is very helpful but we do not need this much information on embryonic period for this project. You can summarise this information in introduction, so that it provides a starting point and fetal development can be further expanded through the project. The rest of the information regarding system development seems to cover the important points; however it still needs work (for e.g. “second trimester muscular development” section is clearly missing some bits).

The abnormality section only includes one abnormality (Duchenne Muscular Dystrophy). This abnormality is well described but it needs to be referenced. An image of the clinical manifestation of the disease can clearly help with understanding. There are lots of other abnormalities that you can include in this section (We learnt from the musculoskeletal development lecture that musculoskeletal conditions form 20% of all abnormalities at birth). You can also refer to “limb development lecture” to find information on musculoskeletal abnormalities.

Finding information on historic findings might be a little challenging. A suggestion I can make is to search for old articles in PubMed (by adjusting the year). These articles can include key historical events. Review articles that summarise historic findings related to musculoskeletal development may also be helpful. You also need to find information on current research.

Finally, you should add an introduction to your project. It seems like you are more focused on muscular development rather than “musculoskeletal” so you can mention that in your introduction. You can also show creativity by drawing your own diagrams, adding images, and tabulating timeline data. You should also fix the references by putting all the references under one subheading in the bottom of the page.

--Mark Hill These are good critical reviews of the projects with some useful comments.10/10

Lab 10 Assessment

Research article- The Involvement of Neural Retina Pax6 in Lens Fiber Differentiation

<pubmed>15855760</pubmed>

Specific interactions that occur between neural and ectodermal tissues as a result of regulated gene expression and controlled signalling events are necessary for proper eye formation. The homeobox gene Pax6 is proved to be essential for eye development in both vertebrates and invertebrates. Pax6 expression for the retina anlage has been revealed to be crucial in the development of different retinal cells. In this study, lab techniques such as plasmid construction, in ovo microelectroporation, in situ hybridization and section immunostaining were performed to examine the expression of several transcription factors in the lens of Pax6-negative optic vesicle eye in chick embryos. Initially, it was shown that the expression of a negative version of Pax6 isoform in developing optic vesicles of chick embryos prevents proper lens development at the lens vesicle stage as well as resulting in optic cup deformation. Following this finding, the molecular events underlying deformed lens formation were further explored.

A Pax6-EnR gene which effectively repressed endogenous Pax6 activity in neurons was used to examine the role of Pax6 in optic cup formation and lens differentiation. It was observed that overexpression of Pax6-EnR in optic vesicle results in abnormal optic cup formation. In addition, a severely deformed lens was formed in the Pax6-negative optic vesicle eye. The development of the lens was significantly delayed at stage 24 and the lens was dramatically smaller than the control lens. It was concluded from these findings that Pax6 expression plays an important role in lens development.

The remaining part of this study was focused on determining the molecular pathways underlying the previous findings. Initially, the expression of L-Maf (a transcription factor that has a crucial role in lens differentiation) was investigated. There was almost no reactivity for L-Maf in the deformed lens while the contralateral lens showed normal L-Maf expression. The expression of c-Maf was investigated afterwards. C-Maf is a transcription factor that is strongly expressed in both epithelial and fiber cells. Unlike L-Maf, C-Maf transcripts were normally expressed in both control and malformed lens. This result suggests that the function of Pax6 is not required for c-Maf expression in the lens at stage 24.

Finally, to illustrate how the Pax6-EnR effect is coupled to the down-regulation of L-Maf, the expression of fibroblast growth factor FGF8, a diffusible factor that was shown to activate L-Maf in non-lens cells was investigated. It was found that FGF8 is down-regulated in the neural tissue. This finding suggests that Pax6 in neural retina regulates FGF8 expression, which may maintain L-Maf expression in the lens to be essential for subsequent lens fiber differentiation.

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--Mark Hill 5/5