Welcome to the 2014 Embryology Course!
- Each week the individual assessment questions will be displayed in the practical class pages and also added here.
- Copy the assessment items to your own page and provide your answer.
- Note - Some guest assessments may require completion of a worksheet that will be handed in in class with your student name and ID.
|Individual Lab Assessment|
|Lab 12 - Stem Cell Presentation Assessment||More Info|
Lab 1 Assessment
<pubmed>25071849</pubmed> summary: This study was done to compare the clinical outcomes between fresh embryo transfers and frozen-thawed embryo transfers.
A total of 1891 cycle contains 1150 fresh embryo transfers and 741 frozen-thawed embryo transfers were studied. All data were transferred directly to SPSS 18 and analyzed.
A long gonadotropin releasing hormone (GnRH) agonist protocol was used in all cycles. Clinical pregnancy was defined by the observation of a gestational sac with or without a fetal heartbeat on ultrasound evaluation on the 30th day after embryo transfer. The number of sacs was taken as the number of implantations.
The results showed that there was a higher clinical pregnancy rate in fresh cleavage-stage embryo transfers than frozen-thawed cleavage-stage transfers but the clinical pregnancy rates were not different significantly.
<pubmed>25077107</pubmed> summary: The study was done to investigate the effect of vitamin D levels on implantation and clinical pregnancy rates in infertile women following in vitro fertilization (IVF).
173 women underwent IVF were included in the study under 3 criteria, including aged 18-41 years, follicle stimulating hormone level 12 IU/L or lower and able to provide informed consent. Vitamin D was determined by serum 25(OH)D levels and samples were collected before oocyte retrieval, while implantation was determined by the presence of a gestational sac, visible by ultrasonography.
χ2 and Student t tests or Mann-Whitney U tests were used to analyze categorical and continuous variables respectively. Multi-variable logistic regression was used to evaluate the relation between serum 25(OH)D level and implantation and clinical pregnancy after adjustment fpr parameters known to influence the IVF sucesss.
The results showed that women with sufficient levels of 25(OH)D had significantly higher rates of clinical pregnancy per IVF cycle started than that with insufficient levels. It also found that implantation rates were higher, but not statistically significant, in the sufficient 25(OH)D group. Therefore, the findings suggested that women with sufficient vitamin D levels are significantly more likely to achieve clinical pregnancy following IVF.
--Mark Hill These are both good articles and summaries (5/5)
Lab 2 Assessment
- <pubmed>23251622</pubmed>| 
--Mark Hill (talk) 15:27, 22 August 2014 (EST) I have uploaded a smaller version of this image, but you still need to adjust the size as it appears on your page to 300px and include the reference. Please use jpg format images if possible. You need to reformat the reference as shown in the class tutorial. (4/5)
Lab 3 Assessment
Neural development during fetal period
<pubmed>21042938</pubmed> <pubmed>12060827</pubmed> <pubmed>23727529</pubmed> <pubmed>16905335</pubmed> <pubmed>17848161</pubmed> <pubmed>18760424</pubmed> <pubmed>16971596</pubmed> <pubmed>17032846</pubmed>
--Mark Hill These are useful references, I needed a single sentence on why you had selected these references for your section. (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>16099997</pubmed> summary: The paper presented the possibility of the therapeutic use of cord stem cells in Parkinson’s disease.
Human mesenchymal stem cells from Wharton’s jelly of the umbilical cord were isolated and induced to transform into dopaminergic neurons in vitro. 12.7% of the cells were successfully transformed and generated through a stepwise culturing in neuron-conditioned medium, sonic hedgehog and FGF8. The cells were transplanted into the striatum of rats previously made Parkinsonian by unilateral striatal lesioning with the dopaminergic neurotoxin 6-hydroxydopamine HCl (6-OHDA). The effects of the transplantation were examined by quantification of rotations in response to amphetamine at 1, 2, 3 and 4 months after transplantation.
It was found that the transplantation of the stem cells corrected the lesion-induces amphetamine-evoked rotation and the cells in the striatum were still viable 4 months after transplantation. These results give the possibility to human umbilical mesenchymal stem cells in treating Parkinson’s disease. However, it is suggested that the examination of the toxicity of growth factor and medium used is important, and the observation of the effects and side-effects for more than 1 year after transplantation is required before human studies
2. There are a number of developmental vascular "shunts" present in the embryo, that are closed postnatally. Identify these shunts and their anatomical location.
Ductus arteriosus: connection between the most cranial part of the pulmonary trunk and dorsal aorta
Ductus venosus: connection between the intra-abdominal umbilical vein and the inferior vena cava
Foramen ovale: located in interatrial septum, connecting left and right atria
Umbilical arteries: branch from the internal iliac arteries in the pelvis and connect to the placenta
Umbilical vein: connection between placenta and portal vein, or ductus venous
--Mark Hill Shunts are fine. (4/5)
Lab 5 Assessment
Congenital Laryngeal Webs
Congenial laryngeal webs are caused by failure of recanalization of the laryngotracheal tube during the third month of gestation. Findings suggested that congenital laryngeal webs can be explained by abnormal development of the epithelial lamina, the laryngeal cecum, or the vestibulotracheal duct . It has also been reported that there is an association between anterior webs, the most common laryngeal webs, with deletions of chromosome 22q11.
In human embryo, congenial laryngeal webs are formed during embryogenesis of the laryngotracheal groove . The developing laryngeal is temporarily obliterated by actively proliferating epithelium, however, the lumen is normally re-established as the vocal cords. This abnormality is resulted from incomplete resorption of the epithelial layer during the 7th and 8th week of intrauterine development.
--Mark Hill very good (5/5)
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. (pancreas)
In this study, the distribution of chromogranin A, insulin, and glucagon in 25 human fetal pancreases was studied. Immunohistochemical reactions were carried out and sections of pancreas were labelled with antibodies to chromogranin A, insulin and glucagon.
Immunopositive reaction to chromgranin A was resulted from week 8 of development onwards. During the development of pancreas, the population of endocrine cells increased and pancreatic islets are formed. The majority of cells in the pancreatic islets were found to be chromogranin A that located in the cytoplasm. Chromogranin A immunoreactive cells were also found in glandular ductal epithelium of 8-9-week fetuses, suggesting that the cells formed a population of precursors of endocrine cells without synthesizing hormones.
The express of chromogranin A, which is higher than that of insulin and glucagon, during differentiation of pancreatic endocrine cells suggested that this can be a marker for studies of the mechanisms of endocrine development of pancreas.
2. Identify the embryonic layers and tissues that contribute to the developing teeth.
Tooth germ: aggregation of cells derived from the ectomesenchymal cells from neural crest and ectoderm of first arch. It is then organized into 3 components of the tooth germ, which are the enamel organ, dental papilla and dental follicle for the teeth development.
--Mark Hill very good article, you have not identified specific tooth layers. (3/5)
Lab 8 Assessment
1. Provide a brief time course and overview of embryonic development of either the human testis or ovary. (2-3 paragraphs)
Gonads are developed from the mesothelium of the posterior abdominal wall, the adjacent mesenchyme and the primordial germ cells. The development begins in week 5 where the mesothelium medial to the mesonephros of the developing kidneys thickens and forming the paired gonadal ridges.
The primordial germ cells are the precursors of oocytes that they migrate from the yolk sac to the mesenchyme of the gonadal ridges between weeks 3 to 5 and incorporate into the primary sex cords. The sex cords extend to the medulla of the future ovary and regress by week 8.
During week 8, gonad begins to develop into ovary due to the stimulation from germ cells. The primitive medullary cords in the ovary degenerates and the primordial germ cells differentiate under the influence of placental gonadotropins. The germ cells undergo mitotic divisions and differentiate into several million oogonia. Around week 16 to week 20, the primitive follicles organize within the fetal ovarian cortex. By 5-6 months gestation, the primitive follicles are enveloped by a layer of epithelial cells and become primordial follicles. During the development, the ovaries descend into the pelvis by the third month.
2. Include an image from the historic genital embryology section of the online notes in your description.
Reference: Bailey, F.R. and Miller, A.M. (1921). Text-Book of Embryology. New York: William Wood and Co.
--Mark Hill Good summary, you have not provided sources and I only wanted the embryonic period covered. (3/5)
Lab 9 Assessment
The project was done well overall with lots of information and a good structure. However, I am a bit confused about the sections “respiratory” and “lung development stages”. I guess “lung development stages” is also under “respiratory”, but it seems that they are separated into two big sections.
The introduction clearly explains the development of respiratory system. It is good to divide respiratory tract into 2 main parts and explain them separately. It would be better if it includes a sentence like ‘this website will focus on fetal development of respiratory system.
Using table to explain different stages of lung development is a good idea. It would be easier to read if they are typed in point forms with some images included.
More images could be added under current research, models and findings for easier understanding. Some information should be added under current models.
The historic findings and abnormalities are good and informative.
Some images do not have the information about copyright. It would be better if there is a title for each image included.
In terms of referencing, they are missing in the sections under introduction, conducting zone and respiratory zone. In-text references are also missing in the table about the stages and features of lung development. Also, the images used have not been referenced. Reference list at the end rather than under each section should be used instead.
It is overall a good project and well-researched. More images can be included to balance with the huge amount of text.
The introduction is good and describes the project well. It is good to mention the function of renal system. It would be better if it states that the website will be focused on fetal development, current research and abnormalities to give a better understanding of the content.
Information under historic findings is missing, it would be a good way to start it by looking at textbooks. Images, bullet points and table can be used for an easy understanding of this section.
Using timeline to summarise the development of kidney is a good idea, however it would be clearer if a table is used, more descriptions under each stages and some images are include. Also, some references should be included in this section.
There are a lot of details under development, current research and abnormalities. It would be easier to read if they are written in point form. It is a good idea to divide renal system into several parts (kidney, urethra…) for the explanation of development. For the abnormalities, it is well-researched but some of the details are missing. It would be better if the each type of abnormalities is discussed equally.
Regarding the images, it is good and clear to explain each of them. The only problem is that there is no copyright information under the file “kidney ascent.jpg”.
The project is informative but lacking some information under historic findings and the developmental timeline.
Introduction is good as it describes and gives an overview about what is happening in the fetal period for foregut, midgut and hindgut. However, it would be better if it mentions that the project is focusing on fetal development, abnormalities, current researches, etc.
It is clear to separate the timeline of GIT development for hindgut, midgut and foregut. It is well-researched with much information in this section. However, it would be easier to follow if a table is used and images are included.
The hand-drawn images can explain the development well, however the blue colour for labelling is a bit difficult for reading. It would be better if a darker colour is used.
It is a good idea to explain the abnormalities in definition and the causes. Some more abnormalities can be included as well as images for better understanding.
There is only one reference in recent findings. More researches could be done in this section. Also, a section about historic findings could be included as well.
There are a few spelling errors, such as “esenchyme” in the hindgut section and “tot hat of” under midgut section. Some proof-readings are needed.
The referencing is overall good, but some more researches have to be done under some sections (abnormalities and recent findings). It is easy to follow as there is a reference list at the bottom of page.
It is overall a good project as the development during fetal period is well described. However, more information about recent findings and abnormalities could be included, with the use of images to illustrate the contents.
The project would be easier to follow by having an introduction that give readers an idea about what is going to be covered in the website.
Under the section about system development, it contains lots of information and it is well researched. Using bullet points is good as it is easier to read, however some of them could be join together into a small paragraph which would increase the readability. It is good to see a related video about the development of reproductive system and it explains well about this topic.
It is a great way to explain abnormalities in terms of female, male, and both. Maybe try to put a table at the top to summarise the abnormalities so that it would be easier to follow. More images are needed in this section, just like the one illustrating abnormalities of uterus and vagina.
It is well-researched under historic findings, try to put more related images to make this section more interactive. Also, it would also be good to illustrate the content in this part by a timeline, followed by the explanation of each event.
In terms of referencing, in-text references are missing in the system development, current research and historic findings.
For the image file “Image.jpg”, which is about sexual differentiation, it is a good image that explains the differentiation clearly, however, it would be better to put a description or title below it to make it more relevant to the project. It is good to see some hand-drawn diagram and they match the topic and explain information well. I found it a bit hard to read the labels on the image “labelled drawing of testes.jpeg”, maybe upload the image by scanning rather than taking a photo of it would be better.
It is overall a well-researched project. The next thing to do is to include an introduction, some more in-text references and some related images.
The introduction clearly states the content in the website, which is good as this can prepare the readers for understanding. However, it would be better if some information about integumentary system, such as functions, is included in this section.
The development of integument system includes a lot of information. They are presented in good structure by the use of table for skin and nail. It is a great way to put some images in the table for easy understanding of the description in the development of teeth.
The recent findings area is well-researched. I would suggest try to put the content into small paragraph or in several points as the amount of text is a bit too much. Some images should be included as well.
Abnormalities section is great with the help of the images. It would be good if some more abnormalities are included. There is a lot of details under historic findings, try to illustrate them with the help of images.
In-text references should be included in the sections under development, recent findings and historic findings.
The project is well prepared. It would be better if some more images are included and the function of integument system is stated in the introduction.
Introduction is missing in the project. It would be great to include the functions of endocrine system and the contents that will be covered including system development, abnormalities, current research, etc.
There is a lot to cover in endocrine system, it is a great way to separate timeline and recent findings under each individual organ. Using table to illustrate the function of hormone is good, however, I think it would be better to have a summary of hormone in a table form at the top/the end of all individual organs. The parathyroid gland and pancreas are well-researched with the use of images. More information has to be included in other sections.
More work has to be done on abnormalities. Actually, they could be separated under each organ, just like current findings. It would also be good to see historic findings under each organ.
In terms of referencing, there is no in-text reference and the reference list at the bottom is empty at this moment. This project overall has a good structure, but more information and images are needed.
Introduction is missing. Some information about the functions of the systems and topics going to be covered should be included here. The section ‘making gains’ is funny. However, more work has to be done to make it more interesting.
For the timeline, more information is needed. It would be great to include a table here and describe the changes during different stages (microfibers formation…). Table is also useful to explain the second trimester muscular development
The information under background embryonic development can be summarised and put under introduction as this project should be focused on fetal development.
It is great to have molecular and cellular regulation. However, more diagrams are needed here. It would be better if they are stated in several points rather than a big paragraph. Also, more images are needed for other sections, it would be good to draw the picture as well.
For abnormalities, in-text references are needed. Also, some more abnormalities should be included with the use of images to illustrate them.
Overall, there is a pretty good structure of the website. It could be improved by including some current and historic researches on this topic. Also, more images are needed (as there is none now) to make the webpage more interesting and informative. More contents should be included as well.
--Mark Hill Very good peer feedback. (9/10)
Lab 10 Assessment
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.
The researchers investigated the functional changes of olfactory sensory neurons (OSNs), which express mouse odorant receptor 23 (MOR23) with a known ligand (lyral), during the first postnatal month. Also, as olfactory marker protein (OMP) is recognized as a molecular marker for mature OSNs, it is hypothesized that OMP has an important role in functional maturation of OSNs.
In their research, genetically targeted MOR23-IRES (internal ribosome entry site)-tauGFP mice (with WT-MOR23 neurons) were used to record MOR23 neurons that coexpress green flurescent protein (GFP). Also homozyhous double mutant mice (with OMP -/- MOR23 neurons) were generated.
To investigate whether OSNs undergo functional changes during development, the odorant responses in individual neurons from animals at different ages (P0-P30, where P=postnatal day) were measured by perforated patch-clamp recordings on the dendritic knobs on individual OSNs. The results indicated that OSNs exhibit faster response kinetics during development. Furthermore, the effects of OMP deletion on functional properties of OSNs were also studied through the homozygous OMP -/- mice. It was found that OMP deletion results in OSNs with slow response kinetics, suggesting the OMP is necessary for the kinetic changes during the OSNs development. In addition, the selectivity of OSNs changes during the first postnatal month was tested and it was demonstrated that MOR23 neurons from P30 mice has higher selectivity to lyral. In terms of behavior test, the researchers also observed that WT but not OMP -/- mouse pups prefer the biological mother when the biological mother and another unfamiliar lactating female was given to choose.
In conclusion, the researchers showed that OMP is necessary for the maturation process in olfactory system. Also, MOR23 neurons from P30 mice have a faster response kinetics, higher sensitivity and higher selectivity when compared to the neurons from P0 mice. The results also suggested the maturation process of OSNs coincides with early development of the smell function and is critical for pups to form mother preference.
Links: Smell Development
--Mark Hill (5/5)
Lab 11 Assessment
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.
Loss or dysfunction of trabecular meshwork (TM) cells is associated with the development of pathologically elevated intraocular pressure (IOP) that lead to gluacoma. In the research, it was demonstrated that mouse iPSCs can be induced to differentiate into trabecular meshwork (TM) like cells that are suitable for autologous transplantation.
TM-like cells (iPSC-TM) were produced by co-culture of mouse iPSCs with human TM cells for up to 21 cells. Morphological, immunohistochemical and functional tests were carried out to characterize the cells. The tests showed that the iPSC-TM cells were morphologically similar to human TM cells that they can express many markers of TM cells and also pluripotency markers includinf Nanog, Oct4, Sox2. The cells also developed the ability to phagocytose particles. In addition, the cells showed the behaviour characteristic of TM cells as there was an increase in the production and secretion and myocilin and matrix metalloproteinase-3 when the cells were exposed to dexamethasone or phorbol 12-myristate acetate respectively.
Therefore, iPSCs that resembles native TM cells can be induced. They can be transplanted into glucomatous eyes with elevated IOP as they can restore the function of TM.
--Mark Hill (4/5)