User:Z3289829

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Lab 4 Online Assessment

1. The allantois, identified in the placental cord, is continuous with what anatomical structure?
2. Identify the 3 vascular shunts, and their location, in the embryonic circulation.
3. Identify the Group project sub-section that you will be researching. (Add to project page and your individual assessment page)

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--Mark Hill 09:38, 3 August 2011 (EST) All 3 questions from Lab 1 need to be completed before Lab 2.

Class Attendance

--Z3289829 12:56, 28 July 2011 (EST)

--Z3289829 12:53, 4 August 2011 (EST)

--z3289829 12:21, 11 August 2011 (EST)

--z3289829 11:52, 18 August 2011 (EST)

--z3289829 11:07, 25 August 2011 (EST)

--z3289829 11:37, 1 September 2011 (EST)

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Laboratory Assignments

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Lab Assessment I

1. Identify the origin of In Vitro Fertilisation and the 2010 Nobel Prize winner associated with this technique.

The first pregnancy achieved through in vitro human fertilisation of a human oocyte was reported in the Lancet from the Monash university in 1973, although it only lasted a few days. The first successful IVF was carried out in the UK in 1978 by Robert G. Edwards, later awarded the Nobel Prize in Medicine “for the development of in vitro fertilisation” in 2010.

2. Identify a recent paper on fertilisation and describe its key findings.

Lisa Moran et al. (2011) assessed the effect of a high-protein weight-loss program with exercise pre- assisted reproductive technology (ART) treatment on pregnancy and live birth outcomes in overweight and obese women. The high-protein weight-loss diet resulted in a significantly reduced weight compared with no treatment. A reduction in waist circumference was associated with increased chances of pregnancy. The overall pregnancy rate was 53% for the intervention and control group combined (compared with the expected spontaneous pregnancy rates of <10% per month in this population). These results established the efficacy of lifestyle treatment for overweight women in ART.

3. Identify 2 congenital anomalies.

Trisomy 21 (Down Syndrome) & Trisomy 18 (Edward Syndrome)

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Lab Assessment II

1. Identify the ZP protein that spermatozoa binds and how is this changed (altered) after fertilisation.

The zona pellucida is an extracellular matrix that surrounds the oocyte and early embryo. It is composed primarily of three to four glycoproteins which have various functions in fertilisation. The protein encoded by zona pellucida glycoprotein 3 (ZP3) is the primary spermatozoa receptor during fertilisation. The binding of ZP3 to sperm activates a range of intracellular signal cascades, which culminate in fusion of the plasma membrane and underlying outer acrosomal membrane (i.e. the acrosome reaction). Fusion of the sperm with the oocyte triggers a release of calcium ions, which results in depolarisation of the oocyte plasma membrane, by which fusion of another sperm is prevented. The rapid depolarisation provides an early block to polyspermy and is mediated by the cortical reaction.

2. Identify a review and a research article related to your group topic. (Paste on both group discussion page with signature and on your own page)

Review Article: Klinefelter Syndrome [1]

Research Article: Klinefelter's syndrome (XXY) as a genetic model for psychotic disorders [2]

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Class exercise: Upload Sample Image

468px-Differentially expressed RefSeq genes in human trisomy 21

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Lab Assessment III

1.What is the maternal dietary requirement for late neural development?

Iodine is essential for the synthesis of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). These hormones act by regulating the metabolic pattern of most cells and play an important role in the process of early growth and development of the brain. Iodine deficiency during pregnancy leading to hyperthyroidism in the foetus results in cretinism, characterised by severe mental retardation. Therefore supplements of iodine can prevent these abnormalities if taken before conception and during the first two months of pregnancy.

2. Upload a picture relating to you group project.

Magnetic Resonance of Head MRI from patient with Down Syndrome and Klinefelter's Syndrome

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Lab Assessment IV

1. The allantois, identified in the placental cord, is continuous with what anatomical structure?

The allantois is a sac-like structure which appears on approximately day 16 from the caudal wall of the umbilical vesicle that extends into the connecting stalk. During folding, the terminal part of the hind gut dilates to form the cloaca, which is primordial for the urinary bladder and rectum. The allantois is carried backwards in folding and is continuous with the cloaca region of the hind gut.

2. Identify the 3 vascular shunts, and their location, in the embryonic circulation.

- Ductus arteriosis: connects the left pulmonary artery and the descending aorta

- Ductus venosus: connects the portal and umbilical veins to the inferior vena cava

- Foramen ovale: connects the right and left atrium

3. Identify the Group project sub-section that you will be researching.

History (with an included timeline), Aetiology and a case study

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Lab Assessment V

1. Which side (L/R) is most common for diaphragmatic hernia and why?

Congenital diaphragmatic hernia occurs on the left side in 85% to 90% of cases. The predominance of left-sided may be related to the earlier closure of the right pleuroperitoneal opening.

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Lab Assessment VI

1. What week of development do the palatal shelves fuse?

The primary palates in the human embryo fuse between stage 17 and 18, from an epithelial seam to the mesenchymal bridge. The secondary palate, fuse in week 9 in the human embryo. The fusion of the secondary palate requires the early palatal shelves growth, elevation and fusion during the early embryonic period. The fusion incorporates both secondary palates and the primary palate.

2. What early animal model helped elucidate the neural crest origin and migration of neural crest cells?

The chicken/quail chimera’s model undertaken by LeDouarin in the 1980s was a key experiment in the understanding of the pattern of neural crest migration. It was a transplantation and histological processing to identify the migration path and final destination of transplanted neural crest cells.

3. What abnormality results from neural crest not migrating into the cardiac outflow tract?

Tetralogy of Fallot, is the cardiac abnormality which may occur from abnormal neural crest migration.

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Lab Assessment VII

1. Are satellite cells (a) necessary for muscle hypertrophy and (b) generally involved in hypertrophy?

a) Satellite cells are not necessary for muscle hypertrophy.

b) However, they are required for both the de novo formation of new fibres and fibre regeneration. Thereby, playing a minor role in the overall hypertrophic response.

2.Why does chronic low frequency stimulation cause a fast to slow fibre type shift?

Slow twitch (oxidative) skeletal muscle fibres are known to contain a large number of myonuclei and satellite cells compared with the fast- twitch (glycolytic) fibres. Studies have shown that fast-to- slow fibre type transition are linked to increasing cell activation, content and fusion to transforming fibres, especially within the IIB fibre population . Chronic low frequency stimulation (CLFS), a highly standardised model of muscle training, copies the electrical discharge pattern of slow motor neurons that innervate slow-twitch muscles. CLFS induces the transition from type IIB to types IID and IIA mainly in regenerating muscle. Additionally, it activates all motor units of the stimulated muscle, therefore challenging the adaptive potential of the target muscle. In a decent satellite cell population, CLFS can induce satellite cell content and activity, and large fast-to-slow phenotypic changes .

Critique of Trisomy 21

General Structure: The sub-heading structure is a little out of order, for example ‘Recent Findings’ should be placed at a later stage, whilst a ‘history’ subheading and/or ‘Epidemiology’ would have been more competent at the top. Also, of the sub-headings aren’t worded well, for example ‘some recent findings’, would read better as just ‘Recent findings’. Content is poor in areas such as ‘Trisomy 21 Karotypes’, more detail could have been included in explaining each one. ‘Heart defects’ and ‘limb defects’ also lacked a substantial amount of detail.Most of your images do not have a copyright clearance statement. No student drawn image should have at least 1 or 2.

Introduction: The introduction is very wordy and I don’t feel it gives a good opening to the disease. It reads poorly in structure. The introduction is the first thing that is read, so this needs to be improved. Also, the history of the disease is not explained well, if there is not going to be subheading for it, the origin of the disease should be outlined in the introduction. The image included is good, however the copyright clearance statement is not clearly supplied. The external links prove to be very helpful, however I think they are ‘overwhelming’ to have at the start, a better position for these links may possibly be the bottom of the page.

Some recent findings: The name of this sub-heading is not proficient. The quotes from the readings clash with points 1 and 5 of the Group Assessment Criteria, because you have not gone to the effort of explaining it in your own words, remember that the reader’s are your peers.

Trisomy 21 Karotypes: Good use of images, however the detail is lacking here. How does karotyping actually work? Maybe the descriptions in each image can be incorporated under the sub-heading.

Heart Defects and Limb defects: Only 1 image. No images for heart defects, a visual aid is necessary for this section. Also, where are all the references?

Prevalence: Nothing from Australia? I’m also not quite sure why the picture of John Langdon Down is under this sub-heading, should be under “history’ or introduction.

Down ’s syndrome screening: Nice use of the table. I think this is the best explained sub-heading, with plenty of descriptions and detail. The image is uploaded in the correct manner. Could have put the ‘terms’ with the glossary below.

Meiosis I and II + Aneuploidy: Relevance? Information should probably have been included in ‘Recent findings’.

Trisomy growth charts: You should use your own words to explain the charts.