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Online Assessment

Lab 1 Assessment

Article 1

<pubmed>24760595</pubmed> The following case study investigated the effects of hepatitis B virus (HBV) infection on sperm parameters, ovarian stimulation, and outcomes of in vitro fertilization (IVF) and embryo transfer, as the impact of HBV on human infertility was questionable. During this study, a total of 224 couples were identified, where either one or both partners were HBsAg-seropositive, and were undergoing their first IVF and embryo transfer cycle. The morphology of their sperm was analysed, as was the quality of their embryo rate, the duration of infertility and their fertilization rates, and then compared to those of 448 HBsAg-seronegative couples. In all four cases, the results of the HBsAg-seropositive couples were inferior to those of the HBsAg-seronegative couples, expressing significantly lower normal sperm morphology, top-quality embryo rate and fertilization rates, and significantly prolonged durations of infertility. It was noted however, that in regard to clinical pregnancy rates, there was no significant difference between the two groups. Based on the case study results, it was concluded that HBV infection was likely to cause infertility.

Article 2

<pubmed>24602756</pubmed> The following case study sought to investigate whether assisted reproductive technology (ART) treatments had any impact on the sex ratio of babies born. Using the United Kingdom records of women who have conceived children between 2000 and 2010 using intrauterine insemination, IVF, or intracytoplasmic sperm injection (ICSI), the records of a total of 106,066 babies born to 76,994 mothers were analysed. The results showed that each form of ART resulted in a varied sex ratio, the most significant variation occurring from IVF with 52.1% of babies born male, and the least variation occurring from ICSI embryo transfer, with 49.3% of babies being born male. It was also found that when the embryos were transferred during the blastocyst stage in ICSI and IVF, as opposed to during the early cleavage-stage ET, it resulted in approximately 6% more males being born. It was concluded however, that due to the significantly increasing number of babies born using ART treatments, more research was needed into the causes of the gender bias after such treatments.

Lab 2 Assessment

These histological views show the morphology of the kidneys of wildtype mice (left) compared to those of transgenic line A homozygous mice (right) that have been injected with Gremlin, an embryonic gene that plays a role in nephrogenesis. These images show what can occur to the morphology of the kidney if this gene is over-expressed.

Lab 3 Assessment

The kidneys first develop in the embryo by a process called nephrogenesis, in which self-renewing mesenchymal renal stem cells produce nephrons to form a simple embryonic kidney, called the pronephros. Nephrons are the main functional unit of the kidney.

An embryonic gene named gremlin (GREM1) has been found to play a key role in the formation of the kidneys and nephrogenesis in general. When fully formed, the expression of this gene is relatively low in an adult. However, it is thought that many renal diseases and their progressions are linked to an overexpression of this gremlin gene.

Nephrogenesis is stimulated by the signaling between the epithelial ureteric buds and progenitor cells, causing nephrons to develop and the ureteric buds to branch.

At birth, although the infant’s kidneys are developed enough to maintain homeostasis and are sufficient for growth and development, their functional capabilities are decreased. This is a result of the transition from depending on the placenta to maintain homeostasis of fluid and electrolyte balance while in-utero, to maturation of the neonatal glomeruli once born.

Determining nephron number is important: it can show the success/extent of nephrogenesis, and thus be used to determine if any and what genes and environmental factors may aid this process; a low nephron count has been linked to multiple cardiovascular and renal disease later in life.

The overexpression of the gremlin gene (GREM1) has been found to be a cause of renal disease.

Lab Attendance

Lab 1 --Z3465654 (talk) 12:45, 6 August 2014 (EST)

Lab 2 --Z3465654 (talk) 11:18, 13 August 2014 (EST)

Lab 3 --Z3465654 (talk) 11:16, 20 August 2014 (EST)

http://www.ncbi.nlm.nih.gov/pubmed

PubMed