From Embryology
Revision as of 17:25, 17 August 2011 by Z3332183 (talk | contribs)

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)

Lab Attendence

--Z3332183 12:57, 28 July 2011 (EST)

--Z3332183 13:02, 4 August 2011 (EST)

--Z3332183 11:09, 11 August 2011 (EST)

--Mark Hill 10:09, 3 August 2011 (EST) Where are your answers to first lab assessment? Need to be completed before Lab 2.

Lab Assessment 1:

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

Robert G. Edwards was awarded the Nobel Prize for his work in the development of in vitro fertilisation. His work in this area first began when he realised that a possible method for treating infertility would be for fertilisation to occur outside of the body. Edwards worked towards finding methods to fertilise human egg cells outside of the womb, since previous experiments had been performed showing that rabbits egg cells could be fertilised in test tubes and result in offspring.

A human egg was first successfully fertilised in a test tube in 1969, although the egg was not able to develop beyond single cell division. Edwards then worked together with Patrick Steptoe, who used the laparoscope to inspect and remove eggs from the ovaries. These mature eggs that were removed from the ovaries and fertilised with sperm were able to divide several times.

On the 25th July, 1978, Louise Brown, the first IVF produced baby was born. In Australia, the first successful case of IVF was in 1980, and since then, the use of IVF as a fertility treatment has become more and more popular with 1, 596 IVF babies being born in 2005.

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

Not all sperm are equal: functional mitochondria characterize a subpopulation of human sperm with better fertilization potential.

•This article describes a study in which fluorescence microscopy was used to assess mitochondrial function of human sperm samples and to determine whether there was a link between mitochondrial function and the functional properties of individual sperm.

•It was found that mitochondrial activity did have a link to the quality of sperm both within different human samples as well as within the same sample.

•The sperm with more active mitochondria were found to contain a lower percentage of chromatin damage, as well as a greater ability to decondense and contribute to early development.

•The activity of mitochondria can be seen as a clear sign of the functionality of individual human sperm. In terms of practicality for fertilisation, cell sorting to produce a subpopulation based on mitochondrial activity and therefore sperm functionality may be possible.

Reference: Sousa, Ana Paula., et al. Not all sperm are equal: functional mitochondria characterize a subpopulation of human sperm with better fertilization potential. PLoS ONE. 6(3):e18112, 2011. [1]

3. Identify 2 congenital anomalies

Klinefelter syndrome

Larsen syndrome

Lab Assessment 2

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

The ZP protein that spermatozoa binds to is the ZP3 protein. After this binding has occurred, the acrosome releases degradative enzymes which allow the sperm to penetrate the zona pellucida.

2. Identify a review and a research article related to your group topic.

Review Article:The genomic basis of the Williams – Beuren syndrome •Williams syndrome is a genomic disorder with symptoms including mental retardation, visuospatial impairment & overfriendliness.

•It is caused due to a hemizygous contiguous gene deletion with regards to chromosome 7q11.23.

•This review article deals with the genomic assembly of the region involved in Williams syndrome as well as the chromosomal mechanisms such as deletions and duplications and the consequences of these.

Reference: Schubert, C. The genomic basis of the Williams – Beuren syndrome. Cell, Mol. Life Sci. 66:1178-1197, 2009 [2]

Research Article: Functional, structural and metabolic abnormalities of the hippocampl formation in Williams syndrome •In this study, neuroimaging (PET and fMRI) was used to investigate the hippocampal structure, function and metabolic integrity of 12 people with Williams syndrome compared to 12 healthy controls.

•N-acetul aspartate can be seen as a marker for synaptic activity and measures of this were reduced in those with Williams syndrome

•Although regular hippocampal size was maintained in both groups, slight changes in the shape were present.

•Through the results of the investigation, it was suggested that the neurocognitive abnormalities seen in Williams syndrome may be partly due to hippocampal dysfunction.

Reference: Meyer-Lindenberg A., et al. Functional, structural and metabolic abnormalities of the hippocampal formation in Williams syndrome. J Clin Invest. 115(7):1888-95, 2005 [3]

Lab Assessment 3

Differentially expressed RefSeq genes in human trisomy 21

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

2. Upload a picture relating to you group project. Breakpoint identification in individuals with deletions in the WS region and atypical phenotypes.jpg