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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)




LAB ATTENDANCE

Z3290808 12:54, 28 July 2011 (EST)

z3290808 12:32, 4 August 2011 (EST)

z3290808 11:34, 11 August 2011 (EST)

z3290808 12:25, 18 August 2011 (EST)

z3290808 11:35, 1 September 2011 (EST)



--Mark Hill 09:55, 3 August 2011 (EST) Where are your Lab 1 assessment answers?



LAB 1 ASSESSMENT

Identify the origin of In Vitro Fertilization and the 2010 nobel prize winner associated with this technique.

  • In vitro fertilization (IVF) is a fertility technique with a history that can be traced back to as early as the 1890's when the transfer of rabbit embryos from one mother to another was achieved successfully by Walter Heape (Metro IVF, 2011). The first ever attempt to fertilize a human egg in vitro was in 1973, although this attempt was unsuccessful as the embryo failed to implant itself into the wall of the uterus. The first successful attempt at IVF was with the birth of Louise Brown on 25th July, 1978, in Oldham, Greater Manchester, UK. Brown became known as the world's first successful IVF baby conceived outside the human body (Monash IVF, 2011). Credit for this achievement was given to embryologist Dr. Robert G. Edwards and gynecologist Dr. Patrick C. Steptoe.
  • Dr. Robert G. Edwards was awarded the 2010 Nobel Prize in Medicine or Physiology for his development of IVF.


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

  • This article’s main objective is to examine the effect of a woman’s body mass index (BMI) on ovarian response to stimulation and the outcome of IVF. Singh et al., (2011) found that oocyte quality decreased with increasing BMI; resulting in reduced clinical pregnancy rate and thus impairment of IVF outcome. It was also evident that as the woman's BMI increased, so did the required dose of gonadotropins. This increase in required gonadotropin in obese women undergoing IVF reflected a state of 'gonadotropin resistance' which was shown to lead to "increased number of days required for ovarian stimulation and higher cancellation rates, lower serum peak estradiol (E2) levels, and reduced number of oocyte retrieved" (Singh et al., 2011). Also, increasing BMI of women undergoing IVF led to a decrease in fertilization and cleavage rate, most likely due to poorer oocyte quality as a result of increased BMI. Thus, it is evident that a woman's BMI plays a considerably significant role in how successful IVF will be for her. [1]


Identify 2 congenital anomalies.

  • Trisomy 21 (Down Syndrome)
  • Polydactyly


Reference List

  1. <pubmed>21792549</pubmed>

Metro IVF. (2011). History of IVF. Retrieved August 02, 2011 from http://www.metro.com.my/historyIVF.php

Monash IVF. (2011). History of IVF. Retrieved August 02, 2011 from http://www.monashivf.edu.au/About_Monash_IVF/History_of_IVF.aspx

LAB 2 ASSESSMENT

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

  • The Zona Pellucida glycoprotein that acts as the primary receptor for spermatozoa binding during fertilization is ZP3.
  • Once the sperm binds to ZP3,the acrosome reaction is induced. This reaction involves the exocytosis of acrosomal enzymes which function to digest the zona pellucida, allowing proteins on the surface of sperm to bind ZP2. As a result of this, membrane fusion occurs which in turn causes membrane depolarization; the primary block to polyspermy. Once the spermatozoa fuses into the oocyte, the cortical reaction takes place. This is when the contents of the sperm's cortical granules are released and act to remove carbohydrate from ZP3 (so that it can no longer bind to the plasma membrane of the sperm) and partially cleave ZP2 (which results in hardening of the zona pellucida). These mechanisms prevent additional sperm from entering the egg. [1]

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

Articles on Fragile X Syndrome:

- This review focuses on the molecular and biochemical pathways shown to be relevant in the Fragile X Syndrome. It describes that a mutation in the FMR-1 gene was found to lead to Fragile X Syndrome due to excessive repeats of the trinucleotide sequence CGG which is known to inactivate the FMR-1 gene, making the X chromosome fragile and prone to breakage. This review article also demonstrates the many vital functions of the FMR-1 gene such as its role in RNA transport and stability, thus absence of the protein transcribed and translated from this gene is thought to affect brain development and thus leads to signs of mental retardation. [2]


- This research article explores the two molecular differences of the FMR-1 gene in normal individuals vs. those with Fragile X Syndrome. These differences are an increase in size of an FMR-1 exon containing a CGG repeat and abnormal methylation of a CpG island 250 bp proximal to this repeat. This research article also shows how these two abnormalities repress transcription of the FMR-1 gene, leading to the absence of the FMR-1 protein which is thought to be the contributing factor to the Fragile X phenotype. [3]

Reference List

  1. <pubmed>20831819</pubmed>
  2. <pubmed>21196228</pubmed>
  3. <pubmed>1301913</pubmed>


LAB 3 ASSESSMENT

What is the maternal dietary requirement for late neural development?

The maternal dietary requirement for late neural development is Iodine. Iodine deficiency induces neonatal hypothyroidism (cretinism). This ultimately leads to impairments of cerebellar development as sufficient thyroid hormone is vital for the normal development of the cerebellum during late neural development. [1]

Reference List

  1. <pubmed>21611807</pubmed>

Sample Picture Upload (Done In Lab).

Differentially expressed RefSeq genes in human trisomy 21


Differentially expressed RefSeq genes in human trisomy 21.jpg


File:Differentially expressed RefSeq genes in human trisomy 21


Upload a picture relating to your group project.

FMR4 is silenced in fragile X syndrome

FMR4 is silenced in fragile X syndrome.jpg

File:FMR4 is silenced in fragile X syndrome

--Mark Hill 11:15, 14 August 2011 (EST) Well done. You can also link the reference from the figure legend, like the example below.

FMR4 is silenced in fragile X syndrome [1]

References

  1. <pubmed>18213394</pubmed>

LAB 4 ASSESSMENT

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

  • The allantois, originating from the endodermal layer of the trilaminar embryo, is continuous with the superior end of the developing bladder.

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

  • Foramen Ovale: connects the right and left atria.
  • Ductus arteriosus: connects the pulmonary artery and descending aorta.
  • Ductus venosus: connects the umbilical and portal veins to the IVC.

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

  • Recent Research with a focus on the relationship between Autism and Fragile X Syndrome.


LAB 5 ASSESSMENT

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

  • 85% of Congenital diaphragmatic hernias (CDH) are left sided. The most common form of CDH is the classic posterolateral or Bochdalek hernia. Bochdalek hernia is a congenital anomaly which occurs as a result of the protrusion of intra-abdominal organs (such as the intestines and stomach) into the thoracic cavity (causing the lungs to compress) via an abnormal opening in the infant’s diaphragm. The reason why it is most common on the left side is most probably due to the earlier closure of the right pleuroperitoneal opening. [1]

--z3290808 22:21, 31 August 2011 (EST)

Reference List

  1. <pubmed>12359645</pubmed>


LAB 6 ASSESSMENT

LAB 7 ASSESSMENT

LAB 8 ASSESSMENT

LAB 9 ASSESSMENT

LAB 10 ASSESSMENT

LAB 11 ASSESSMENT

LAB 12 ASSESSMENT