User:Z3333865

Lab Attendance

Lab 1 --Z3333865 11:00, 25 July 2012 (EST)

Lab 2 --Z3333865 10:04, 1 August 2012 (EST)

Lab 3 --Z3333865 11:58, 8 August 2012 (EST)

Lab 4 --Z3333865 11:43, 15 August 2012 (EST)

Lab 5 --Z3333865 10:16, 22 August 2012 (EST)

Lab 6 --Z3333865 11:58, 29 August 2012 (EST)

Lab 7 --Z3333865 10:12, 12 September 2012 (EST)

Lab 8 --Z3333865 10:03, 19 September 2012 (EST)

Lab 9 --Z3333865 10:09, 26 September 2012 (EST)

Lab 10 --Z3333865 10:11, 3 October 2012 (EST)

Lab 11 --Z3333865 09:47, 17 October 2012 (EST) Sorry, I just realised I forgot to log in last time!

Lab 12 --Z3333865 09:47, 17 October 2012 (EST)

Lab attendance logged for all practicals. --Mark Hill 07:56, 18 October 2012 (EST)

Lab Exercises

Lab 1

Question 1

As stated by IVF-worldwide, the history of In Vitro Fertilization (IVF) and embryo transfer (ET) dates back as early as the 1890s. Walter Heape, a professor and physician at the University of Cambridge, England, had been conducting research on reproduction in a number of animal species. He reported the first known case of embryo transplantation in rabbits, long before the applications to human fertility were even suggested. IVF history

IVF-worldwide also explains that in 1965, Robert Edwards together with Georgeanna and Howard Jones at Johns Hopkins Hospital in the USA attempted to fertilize human oocytes in vitro. The first IVF pregnancy was reported in 1973 by the Monash research team of Professors Carl Wood and John Leeton in Melbourne, Australia. Unfortunately, this resulted in early miscarriage. The first ever IVF birth occurred in Oldham, England on July 25, 1978. This birth was the result of the collaborative work of Patrick Steptoe and Robert Edwards. IVF history

Robert Edwards was awarded the 2010 Nobel Prize in Physiology or Medicine for the development of human In Vitro Fertilization (IVF) therapy. His achievements have made it possible to help treat infertility, which affects more than 1 in 10 couples worldwide. 2010 Nobel Prize

Question 2

<pubmed>PMC3353509</pubmed>

Traditional IVF methods involve the assisted fertilization of the oocytes with the spermatozoa. This is performed in the laboratory, whereby the physiological conditions to which the gametes are normally exposed in vivo are simulated. However, INVO (intravaginal culture of oocytes), is a simplified procedure and alternative option to conventional IVF. This assisted reproduction procedure uses the maternal vaginal cavity for incubation, instead of laboratory equipment.

Investigated in this study is the outcome of the INVO procedure and how this compares to the conventional IVF methods. Data was obtained regarding pregnancy, live birth, and single live birth rates. Results of this study showed that the INVO procedure had comparable successful rates with traditional IVF.

Statistics from 2008 on traditional IVF: the pregnancy, live birth, and singleton live birth rates per oocyte retrieval were 41.6%, 33.8%, and 23%, respectively.

Statistics from this study on INVO: the pregnancy, live birth, and singleton live birth rates per oocyte retrieval were 40%, 31.2%, and 24%, respectively.

The study also concluded that the most significant factor determining the success rate was the age of the mother. In terms of pregnancy, live birth, and single live birth rates, a significant decrease was observed across the groups of age from ≤29 until ≥40 years old. Results obtained by this study suggest that INVO procedures could be a viable alternative treatment for infertile patients.

Link to paper on INVO

Mark Hill - Q1 and Q2 good answers. 10/10

Lab 2

In-class exercise

Confirmation of homologous recombination and c-MYC2 expression in ES cell clones.

Confirmation of homologous recombination and c-MYC2 expression in ES cell clones.

(A) Genomic DNA of ES cell clones 1, 14, 18 and 19 and of wildtype ES cells (wt Bruce 4) was digested with EcoRI. Digested DNA was analyzed by Southern blotting with a 5′ probe and a 3′ probe. (wt) DNA fragment of the wildtype c-Myc locus; (rec.) DNA-fragment of recombined hc-Myc locus. (B) Protein extracts were prepared of ES cell clones 1, 14, 18 and 19 as well as of wildtype ES cells (wt Bruce 4) and of a human lymphoblastoid cell line (LCL 1.11). Human c-MYC2 (hu. c-MYC, ca. 62 kDa) was detected with antibody clone Y69. In wildtype ES cells murine c-MYC2 (mu. c-MYC, ca. 64 kDa) was detected. For loading control an antibody specific for glyceraldehyde-3-phosphat-dehydrogenase (GAPDH; ca. 36 kDa) was used. Western blot results were reproduced five times.

Lehmann FM, Feicht S, Helm F, Maurberger A, Ladinig C, et al. (2012) Humanized c-Myc Mouse. PLoS ONE 7(7): e42021. doi:10.1371/journal.pone.0042021

Copyright: © 2012 Lehmann et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Assessment task

Jam2 expression in mouse uterus during early pregnancy.

Question 1

Jam2 expression in mouse uterus during early pregnancy.

(A) In situ hybridization of Jam2 mRNA. (B) Real-time RT-PCR quantification of Jam2 mRNA. (C) JAM2 immunostaining. D1, day 1; D2, day 2; D3, day 3; D4, day 4; D4.5-I, implantation site at day 4 midnight; D4.5-NI, inter-implantation site at day 4 midnight; D5-I, implantation site on day 5; D5-NI, inter-implantation site on day 5; PD3, day 3 of pseudopregnancy; PD4, day 4 of pseudopregnancy; Arrow, embryo. Bar = 150 µm.

Su R-W, Jia B, Ni H, Lei W, Yue S-L, et al. (2012) Junctional Adhesion Molecule 2 Mediates the Interaction between Hatched Blastocyst and Luminal Epithelium: Induction by Progesterone and LIF. PLoS ONE 7(4): e34325. doi:10.1371/journal.pone.0034325

Copyright: © 2012 Su et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Question 2

A protein associated with the implantation process is Hand2.

It is known that levels of this protein increase in uterine cells as progesterone levels rise. In a more recent NIH funded study, researchers discovered that Hand2 is also the switch that turns off estrogen’s stimulating effect on the epithelium.

For the study, the researchers developed a laboratory strain of mice in which the uterus fails to make Hand2. It was found that exposure to progesterone halted growth of the uterine epithelium in mice with functioning genes for Hand2. However, despite exposure to progesterone, epithelial growth continued unchecked in the mice without Hand2 genes.

Furthermore, at the time of implantation, Hand2 was expressed in uterine cells that lie beneath the surface layer of epithelial cells. Experiments have shown that estrogen stimulates the production of growth factors, which cause cells in the epithelial layer to multiply and grow. When progesterone is produced, it spurs the release of Hand2, which stops the production of growth factors. The uterine epithelial cells then stop multiplying, mature, and become receptive to the embryo. This is a key step in the process of implantation.

<pubmed>PMC3320855</pubmed>

Mark Hill - Good answers provided to both questions. 10/10

Lab 3

Question 1

The post-fertilization age (or conceptional age) is the time that has passed since fertilization of the egg. The gestational age, however, is measured from the first day of the woman's last menstrual cycle to the current date. A normal pregnancy can range from 38 to 42 weeks.

The gestational age is approximately two weeks greater than post-fertilization age. Gestational age is more clinically significant because its start date can be clearly determined both before and after birth, whereas the exact moment of fertilization must be inferred.

Post-fertilization and gestational age

Question 2

The somites developed from paraxial mesoderm, and will give rise to sclerotome, dermatome and myotome tissues.

The sclerotome relates to the axial skeleton and the proper functioning of the vertebral column: Sonic hedgehog signalling causes the ventromedial portion of the somite to differentiate into sclerotome.The sclerotome then develops into cartilage (chondrocytes) due to the transcription factor Pax 1.

Dorsolaterally, the dermomyotome develops first, which then differentiates into the dorsal dermatome and the ventral myotome.

The dermatome will contribute to the formation of the dermis due to the neurotrophin 3 factor. The dermis consists of: firstly, a more superficial papillary layer which has fine collagen and elastic fibres and contains small blood vessels (arterioles and capillaries), lymph and nerves. Secondly, a deeper reticular layer with dense collagen fibres and thick elastic fibres and it contains lymph, vascular plexus, nerves and appendages.

The ventral myotome can be split up into the epaxial myotome (dorsomedial quarter) and the hypaxial myotome (dorsolateral quarter). The epaxial myotome will result in formation of the erector spinae muscles and the hypaxial myotome will give rise to muscles of the trunk (ventrally) and limbs. The type of muscle which is formed is skeletal muscle - striated, multinucleated myofibers. Proteins such as Wnt 1 and 3 are related to the expression of genes which will cause muscle development.

Online Embryology course developed by the universities of Fribourg, Lausanne and Bern with the support of the Swiss Virtual Campus - Somite development.

Mark Hill - 10/10

Lab 4

Question 1

One of the invasive prenatal diagnostic techniques is chorionic villus sampling (CVS). A small sample of the developing placenta is obtained to test for genetic abnormalities. To collect this sample, a slender needle is inserted through the abdomen and into the placental tissue. The chorionic villi are then examined in a laboratory. CVS

Genetic abnormalities, such as Down Syndrome or Cystic Fibrosis can be tested for by this CVS diagnostic technique. It is generally performed between 10 and 12 weeks of pregnancy and has emerged as the only safe invasive prenatal diagnostic procedure prior to the 14th week of gestation. <pubmed>16533654</pubmed>

The other invasive prenatal diagnostic technique is amniocentesis. A sample of approximately 16 mL of amniotic fluid is collected from the amniotic cavity. To collect this sample, a long needle is inserted through the abdomen and into the amniotic sac. The embryo and the placenta remain untouched during the procedure. Ultrasound is often used prior to or during the procedure to locate the amniotic sac from which the sample is taken. The test is generally performed at around 16 weeks of prenancy. Amniocentesis procedure.

The fluid can be examined for fetal lung maturity, genetic evaluation and sex determination, the presence of infection, spina bifida and other neural-tube defects,or chromosome analysis to test for conditions such as Down syndrome. To screen for neural-tube defects and Down syndrome, blood tests can be performed. Elevated levels of the alpha feto protein may indicate a developmental abnormality. Amniocentesis testing

Question 2

The following paper describes a therapeutic use of umbilical cord stem cells:

<pubmed>22500090</pubmed>

It has long been known that mesenchymal stem cells can contribute to the alleviation of neurologic deficits. In this paper, researchers investigated the possible mechanisms which could underly the beneficial effect of human umbilical cord-mesenchymal stem cells on spinal cord injury.

Rats used in this experiment underwent surgery to induce neuronal damage. The skin and muscles overlying the thoracic cord were separated and retracted, the T9 vertebral level was removed by laminectomy, and the underlying spinal cord segment was exposed by slitting the dural sheath. A rod was placed above T9 and dropped from a height of 25mm to induce an incomplete partial SCI. Rats were then randomly assigned to different groups. Human umbilical cord blood was obtained from normal full-term pregnant woman. The mesenchymal stem cells obtained from the human umbilical cord blood were transplanted into the boundary zone of the injured site of some rats. Rats without the transplantation were in the control group. Animals received a daily injection of bromodeoxyuridine during the 7 days after treatment. Various experiments were carried out on both the experimental and the control groups and data of both was compared.

One of the tests looked at the area of the cavity of the damaged spinal cord. Through imaging it was found that the cavity volume was smaller in the rats with transplanted mesenchymal stem cells compared to the control group. The recovery of hindlimb function was also assessed. The motor function scores of rats with injected mesenchymal stem cells were significantly higher at 7 weeks after SCI, in comparison to the control groups. Scores demonstrated that the neurological function dramatically improved in treated rats. Thus, human umbilical cord blood-mesenchymal stem cell transplantation led to a significant improvement of behavior as well as the reduction of cavity volume after spinal cord injury.

Cells labelled with bromodeoxyuridine were counted in the ependymal and parenchymal regions. Proliferation of the newly generated cells increased greatly in treated rats as compared with the control rats. This demonstrated that the mesenchymal stem cells derived from the human umbilical cord blood could enhance proliferation of endogenous cells within the spinal cord. It was observed that both endogenous cell proliferation and oligogenesis contributed to functional recovery in the treatment group. Rats were also examined for immunoreactivities. Results showed weak responses for the control groups, yet high responses for the treatment group. This suggests that the presence of mesenchymal stem cells creates an influential microenvironment within the spinal cord. Furthermore, transplantation of mesenchymal stem cells protected injured spinal cord cells from apoptosis.

Taken all his data together, treatment of spinal cord injuries with human umbilical cord blood-mesenchymal stem cells has a neuroregenerative and a neuroprotective effect which could be therapeutically used to treat spinal cord injuries.

Mark Hill - 10/10

Lab 7

Question 1a: Provide a one sentence definition of a muscle satellite cell

A muscle satellite cell is a quiescent stem cell present in muscle tissue between the sarcolema and the basal lamina of a muscle fiber, which becomes activated due to injury and allows for repair and regeneration of the muscle tissue.

Question 1b: In one paragraph, briefly discuss two examples of when satellite cells are activated

Satellite cells are activated when muscle tissue needs to be repaired or regenerated. This is a result of injury or disease.

• Injury can be caused by various events. An example would be a bite from the Australian tiger snake, which contains the myotoxic agent notexin. As studies have indicated, notexin causes the complete breakdown of muscle fibers and loss of functional capacity after 3 days. It was also shown that at 7 and 10 days after injection with notexin, muscles were comprised entirely of regenerating fibers.

• Diseases can be another factor. The quickly worsening muscular disease Duchenne muscular dystrophy (DMD) is the result of a defective gene for dystrophin. Dystrophin is essential for connecting the muscle fiber cytoskeleton to the surrounding extracellular matrix. Studies have shown that DMD results in elevated levels of satellite cells as compared to normal muscle tissue. A mouse model of this disease was used for the first application of muscle stem cell transplantation.

The following happens:

The quiescent satellite cells become activated and proliferate. Cells will then allign and fuse to allow for repair and/or regeneration of muscle fibers. Injured muscle

Question 2 In one brief paragraph, describe what happens to skeletal muscle fibre type and size when the innervating motor nerve sustains long term damage such as in spinal cord injury

Spinal cord damage and other causes of long term injury affecting an innervating motor nerve will result in the partial or complete wasting away of the muscle - atrophy. When considering both complete and incomplete injury to the spinal cord, one of the factors resulting in atrophy and a significant decrease in cross-sectional area of the muscle is the immobilisation and disuse of that tissue. Studies have also shown that 6 weeks after the spinal cord injury took place, increased accumulation of intramuscular fat occurs in conjunction with the muscle atrophy.

It was also noted that fast twitch type 2 muscle fibers became more numerous after complete or incomplete spinal cord injury, as compared to the slow twitch type 1 muscle fibers. It has been suggested that this change occurred as the muscle is no longer exercised on a long-term, consistent basis. It was also determined that in the particular study by Dupont-Versteegden et al. (1998), the affected muscle became more abundant in Myosin heavy chain type 2b. As a result, the muscle was more easily susceptible to fatigue.

Mark Hill - 10/10

Lab 8

Group 1

Firstly, the picture at the top immediately shows us the topic you are discussing: vision. This is good, but you might want to decrease the size slightly by stating the number of pixels in your file description. Your introduction includes the anatomy of the eye, which you should probably put under a separate heading. Expand the introduction a little and tell us what you will be presenting on your site.

The history is quite short – aim for more significant dates and discoveries and try to put them in an organised table. Within your history section you have images relating to development of the optic vesicle and lens. It seems like these should be incorporated in your next section on development. Good images though, but this time increase the size so the reader doesn’t have to open every single one of them to read the labels.

It seems like most work has gone into the section of development, which is good because we are focussing on the development of vision! The content relates really well and shows research has been done. There are a few sentences that strongly suggest they have been researched, however they are not references. This is in particular for the optic nerve and retina sections. Again, make sure the labels on the images can be read without having to open the file. You may also want to put the images together (optic nerve section) so the reader can easily see the changes happening during development. It is really good that you refer to the images within your text. The second half of your development section could do with a few images to complement the text. I personally think you should expand upon the lens development, because this is an important structure of the eye. What happens after migration into the embryo? If you find some related molecular information, eg. essential transcription factors, you could provide a brief explanation of these too and the role they play in vision development.

You started on your current research and a few references are present, as well as an image. I do not know what this image is and there is pretty much no text explaining any research that is currently undertaken. Please expand upon this! The links should probably be listed under the heading ‘external links’ and as you expand upon certain sections, please keep adding to the glossary. For instance, I could not find the term ‘neuroblastic layer’ in the glossary (from the retina section).

With all of your images: please provide a title, description, source, copyright information, student image template. Some of your references will also need to be changed to avoid errors, citation of webpages and doubling-up of references. See the ‘editing basics’ on the embryology website.

Group 2

Your introduction is quite expansive and the first paragraph gives an excellent overview of what the somatosensory system actually is. At the end of the first paragraph you do refer to a picture; however, there is no picture. Please add this to show the somatosensory organisation within the body. In the second paragraph you mention some key timepoints related to the somatosensory development, which is good. After this (“Development of the system entails…lemniscal system.”) the text is probably too specific for the introduction. This can be used as an introduction for your development subheading. Please make sure that you edit the in-text references to proper references which we can access via your reference list. Also make sure you start adding terms to the glossary, eg. dorsal column-medial lemniscal system (I do not know what this means!)

You have started on your history section, but it would be more interesting and easier to read if you put this in a table. For instance: date – description – significant person. Also try to add a few more important discoveries. Again, please provide proper references. See the ‘editing basics’ section on this embryology website.

The central somatosensory differentiation is good and I can see that a lot of effort has been put into this section. The picture is very helpful and complements the text. To some extend it does seem like the sensory neurons only come from the dorsal aspect (going into the dorsal root ganglion), so maybe put a note in there that the dorsal and ventral rami are mixed nerves and both of them will contain sensory neurons that go to the dorsal root ganglion. With this image, you also have to include the student template. Text and references are good in this section and I particularly found the ‘making connections’ section very clear, organised and enjoyable to read. Do make sure that you add to the glossary – in particular terms from the ‘development of the primary cortex section’, and if possible add more images.

The touch section has a fair amount of text, but no images to complement it. This made it a bit boring to read. Make sure the subheadings stand out by making them bold. Most of the text has not been references at all, which is concerning and could potentially indicate plagiarism. I also did not read anything about the development of the various receptors (or hypotheses it no distinct evidence has been provided yet). Keep in mind we are looking at the development of the system, not the physiology. You did put in some interesting facts, such as that cell abnormalities can lead to Merkel-cell carcinoma.

Pain and hot/cold are similar to touch: good description of the physiology, but no development included. References are only provided as in-text citations or listed below, which will need to be edited to include them into the reference list. Include images to complement your text and engage the reader – this also concerns the touch section.

The pressure section has limited information regarding the development. Please include how this develops – what factors are included etc. In my opinion there is too much focus on the adult physiology. We are studying embryology… As mentioned above, please edit references and include appropriate images.

Current research looks good with an interesting image and the appropriate references, copyright and student template. The description helps to understand the image. Maybe add another research project to this section.

Add to the glossary, references and actually name the external links listed as 1) 2) and 3).

Group 3

Your introduction is quite good and gives us a brief overview of the different tastes. I also like it that you touch on the fact that it is important we recognise (via taste) food which would be dangerous to our health. In my opinion, after you mention the research (ending the sentence with …’may exist.’) you should tell the reader what you will be discussing on your page. The few lines on fatty acids does not seem to fit in, and should be part of your history section and possibly current/future research. Some specific information seems to have been researched, such as what umami codes for; however, references have not been provided. Also make sure that the image has the correct information – title, description, references, copyright, student template.

It would be more logical to put the history section next. Following this by the timeline and then go back to the cell biology, receptors and taste map etc.

The history section is good with many significant dates and clear descriptions incorporated in a table. I do see lots of numbers, which I think relate to references. I cannot find these references anywhere, so please edit this and make sure it is included in your list of references. There are also a few references listed in full in the table, so please put these down as proper references. Also, there is no good description for the year 2007 (it is mainly a reference).

The developmental timeline is expansive and very interesting! It really relates to the different developmental stages and tells us what happens over time. I hope you can include images with appropriate labels and information to this table, as it will greatly complement your text. Please do check your spelling, eg. ‘epithelium’ in week 6. Also references in this section are appropriate and are not doubled-up in the reference list. Do check reference 5 as it comes up with a cite error.

The section on cell biology and type 2 receptors is clear and easy to read. I cannot see any references though! Please be careful cause this might indicate plagiarism. The taste map is interesting and I am glad you mentioned research has indicated that the different receptors are in fact located all over the tongue – not just in particular sections. If possible, look for the original paper(s) that made this discovery.

The section on neural pathways is a little more difficult to read and I did not understand some of it. Particular terms are used in sentences which suggest little effort has been put in to explain everything in your own words. This is further indicated by the lack of references in the ‘first order neuron’ section and the majority of the ‘second order neuron’ section. I might be wrong, but then do add all your jargon to the glossary. If possible, also try to find other papers which present the same information to strengthen your points mentioned. Images for both the taste map and the cortex need referencing, copyright info, etc.

Adult tongue and taste buds. It is good you include some anatomy and physiology into your section. Do keep in mind the majority of your project should focus on embryonic development. You included the appropriate names, eg. sulcus terminalis, and I am glad to see that has also been put in the glossary. Some more terms do need to be added, eg. circumvallate. The text is good, clear and easy to read. Images are appropriate and relate to the text but need proper descriptions, citations, etc. A major let down of this section is the lack of references – please include this.

Personally, I found the abnormalities section very interesting! However, you are suddenly talking about all these genes and factors which you have not mentioned anywhere else. It might be good to provide a brief description of these in the development section or incorporate them into your developmental timeline. Images all have copyright information, but other information is missing, such as the student template and/or reference. Please check and add this.

Current research includes a lot of information. All different sections have their references which are displayed in the reference list. If you can, provide links to the website of the research groups working on current projects. Be careful not to just put your reference at the end, as you may also have to reference within the paragraph. Both pictures used will need the student template. The double tongue image will need a reference in its description too.

As mentioned before, add and edit the glossary and reference list. You should also add to the useful links (make this external links) and the image gallery, or delete these subheadings, as there is nothing there now.

Group 4

Your introduction is good and gives a brief overview of what the olfactory system entails. There were a few spelling mistakes, which can easily be corrected. Make sure you do tell the reader what you will be discussing on your page – development of the olfactory system and the particular subheadings you will focus on. The image could do with a few more labels for orientation, but besides that it complements the text and contains the correct citation, student template, etc.

The history section is good and quite extensively researched. Most groups will provide the history in a table, with dates in chronological order (to clearly show history and developing knowledge over time). This might be something to think about. I would suggest a ‘date – description – significant person’ type of format for a table. Good image, but it is displayed next to Pearson instead of Kollman. It is also difficult to see what it is and read the labels without opening the larger version, so you might want to increase its size slightly. Because this is a student image I would like to see the original – if possible provide a link to the Atlas of the Development of Man 2. You should also explain what Kallmann’s Syndrome actually is, because this seems a little vague.

Your timeline of developmental process looks amazing and is enjoyable to read. Some of your words are printed in bold and link to the glossary. In one of your next sections the words link directly to the glossary, so you should probably do he same thing here. I really hope you can add pictures to this table to complement your text! Not quite sure what the line at the bottom (SINUSES:A:…) is doing there… either delete or expand upon this.

Structure: you only have a link here. Please provide text and image to explain the structure briefly. The YouTube link should be there to help the reader understand this section, instead of being the only thing this section is made up of. The video is not your own work, so please add your own work to this!

The normal function section was alright. It has some useful information in there, however, only a single reference listed at the end. It seemed like more references should be included within the paragraph. I would also include the fact that depolarization is an all-or-nothing response. The threshold needs to be reached for depolarization to occur, but there is no build-up over time to reach this threshold. It has to happen at that one instance. The links should be listed under the heading ‘external links’ or, if used as references, incorporated as proper references within the text. The olfactory bulb image is a little small and the description is quite brief. Though, good citation of the source and a student template is present. I think the olfactory bulb image and the epithelium image should be included in the ‘structure’ section.

The abnormality section includes Kallmann’s syndrome and a quick definition has finally been provided! Please include this in the history section too. This section was a joy to read! Very interesting! A lot of effort has been put into the research and references have been done very well. I assume OB stands for olfactory bulb – please indicate this in the text. The dotpoints listed in the ‘clinical features’ section could do with a brief explanations instead of me having to scroll up and down between the text and the glossary. The image is excellent and shows a good simplified concept of what happens. Good descriptions, source citations, etc are added too. It was good to see diagnosis and treatment included.

Current research starts with a link, which seems quite random – include this in the external links section. You found some interesting and current research. References are only listed at the end of each paragraph, but should probably be included within as well. The image relates to one of the projects and descriptions are appropriate. Nothing has been added to the ‘role of odorant receptors’ though (apart from a reference). Please add a brief paragraph to this section.

Terms should be added to the glossary. The reference list also needs checking, because some are the same (eg. 11 & 12) and others do not have a reference (eg. 7 & 17).

Group 5

Your introduction is quite short, but it does state what you will be discussing on your page. You might want to include the normal development in the introduction, to allow for an overview of what normally happens before you actually start on the abnormal development. It just seems a little odd that you have abnormal vision as you title and then almost immediately after that you have a normal eye development heading.

I really like the chronological order used in the normal development section. It might be a bit easier to read if you use dot points. References seems to be fine, however, 4 and 5 are the same. It might also be useful to create a link to the group page on normal vision development.

Abnormal development consists of a few subheadings. Personally, I would delete the lines below the different subheadings. It will make it look more like one section on abnormal development. I think it was a good idea to look at the different parts of the eye related to abnormalities – lens, cornea, retina, etc. You look at different genes which play an important role at a certain developmental stage and you explain the resulting effects. I can see a lot of research has been done on this section. Images will need to be made bigger. They look insignificant with this size and it just seems like the text is going on and on. A lot of terms mentioned in this section are not included in the glossary, eg. Dysgenesis, substantia propria, CRX (what does it stand for?). Please add these in. Again, check your references, because some are the same, eg. 8 & 9.

Ocular manifestation is part of the abnormal development section (I think), so please make sure you show this with the headings. Again, immediately below this seems to be another heading with genetics, which has nothing included… or does LCA belong to genetics? I am a bit confused due to all your different headings and lines which seem to separate parts that may potentially belong together.

In your LCA section I would change the order of text a little: definition (as you have at the start), then epidemiology (which you have at the bottom), then the section on Dr Leber (up to “…placing great emphasis upon the high incidence of hereditary factors.”), lastly a new paragraph on the diagnosis (“As stated in the section on… diagnostic protocol for LCA”). The link to Abnormal Retinal Development does not work and will need editing. I can see that your timeline refers to LCA in particular and it is quite expansive. The one reference provided leads to a website with a timeline that seems to have been copied and pasted into your project. Please change this into your own words and (where possible) provide references to the original papers. The table also seems to be located in a strange position and it may be better to include this information in a table on history (in general), which you do not have at the moment. New research development also focuses on LCA only. Maybe create a separate section at the end where you can mention this and include more current research in brief paragraphs. The image relates well and has the appropriate citation, copyright and student template. The description could include a little more information.

Anophthalmia and microphthalmia are other genetic abnormalities described. Again, with the image you can expand slightly upon the description, but besides that it relates well to your text. Information provided is good, and includes the clinical description, genetic causes and management. Most important is that you use the same layout for your headings throughout your project. Within this one section you are using different subheadings and it all looks a bit chaotic and makes it less encouraging to read. You explain the role various genes play and I would like to know at what week/gestational stage they are important and can cause these abnormalities. Make sure all your references are correct, eg. There is no reference for 30.

It is probably good you only focused on 2 abnormalities caused by environmental factors. Images could really complement the text (although your whole page could probably use a few more images), so please add these. You include some relevant information and statistics, but make sure you also keep adding to the glossary. References are also the same for 45-48, hence these need editing.

In my opinion, firstly change the layout of your page and make it more organised with logical headings. Then focus on some of the other things mentioned above.

Mark Hill - Excellent peer assessment and feedback. 10/10

Lab 9

Question 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>22993381</pubmed>

Leptin levels are elevated in obese subjects and decreased in subjects restricted of food. This study investigates the effects of leptin concentrations on the development of the placenta and global placental gene expression profiles at d11.5. Pregnant mice were used and divided into 3 groups: control, mice that were undernourished and mice that were undernourished but supplemented with leptin. As stated in the study, "placentas from mothers exposed to food restriction preserved the placental labyrinth zone at the expense of the junctional zone, an effect abrogated in the restricted+ leptin group, which had a significant decrease in the labyrinth zone area compared to controls". Furthermore, when comparing the placentas from control and restricted+ leptin mothers there were 1128 genes which were differentially expressed. There were 281 differentially expressed genes between the control group and the restricted group.

This study concluded that being deprived of nutrition relates to a limited availability of energy and a decrease of the junctional zone of the placenta as mentioned above. When high levels of leptin are present, this response was altered and in fact the labyrinth zone had decreased.

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

Ectoderm, mesoderm and the neural crest contribute to the developing teeth.

Development of the teeth involves epithelial/mesenchymal interactions between the ectoderm of the first pharyngeal arch and cranial neural crest ectomesenchymal cells.

• The ectoderm from the first pharyngeal arch contributes to the enamel of the tooth. Some cells from the oral epithelium remain and differentiate locally into enamel-producing ameloblasts

• The majority of the dental papilla of the tooth has been demonstrated to be of neural crest origin. The cranial neural crest cells also give rise to various tooth cell types (odontoblasts, which produce dentine; cementoblast, which secrete cementum to cover the root dentine; osteoblasts, which participate in the formation of dental alveoli; and fibroblasts, which synthesize collagen for the periodontic ligament).

• During odontogenesis, non-neural crest cells have also been observed in the dental papilla region, which are mesodermally-derived migrating cells. These cells create a network of endothelial cells, contributing to the blood vessels in the pulp of the tooth.

Mark Hill - 10/10

Lab 11

Question: 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.

<pubmed>22984641</pubmed>

The introduction of this paper outlines that retrovirus and lentivirus are generally used to produce induced pluripotent stem (iPS) cells. These integrate into the genome and allow for the expression of the specific factors needed (Yamanaka factors) to reprogram a cell to its pluripotent state. Integrating viruses do cause some concern for genome alterations. A fairly new method involves the use of the Sendai virus, which allows for a relatively efficient iPS cell conversion. It has a completely RNA-based reproductive cycle, and sustained transfection of synthetic mRNA transcripts encodes the Yamanaka factors. It has been necessary to use a feeder layer of mitotically-arrested fibroblasts when using mRNA to reprogram cells and this makes the process much more complex. It also takes approximately two weeks to induce pluripotency in human cells.

Improvements include accelerated reprogramming of cells through potentiation of the reprogramming factor cocktail delivered to the cells. This study explains a revised protocol that compresses and streamlines the mRNA reprogramming process, and which supports the rapid production of footprint-free iPSCs from human fibroblasts without the use of feeder cells or other reagents.

Various cocktails of reprogramming factors were prepared, using wild-type Oct4 or M3O. It was quickly established that more colonies were produced by using M3O-based cocktails. The results also showed that adding Nanog transcripts to the cocktail was highly beneficial, especially when M3O cocktails and Nanog were used together. To allow for feeder-independent iPS cell derivation, data shows that it was beneficial that RNA dosing was scaled down in 24-hour transfection wells to compensate for an increase in cytotoxicity. Overall, the kinetics and efficiency were improved with this reprogramming method. It is unknown what causes the increased performance of the 24-hour regimen, but significant might be the fact that dose ramping was achieved within these wells by delivering a decreased volume of medium containing a fixed concentration of RNA. This may have increased the effective density of thinly-plated cultures. Further research into this area will be needed.

According to the authors, their work will extend the appeal of the mRNA method and bring us closer to using iPS cell technology therapeutically.

Mark Hill - 10/10

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