User:Z3330539

From Embryology

Lab Attendance

Lab 1--Z3330539 11:49, 25 July 2012 (EST)

Lab 2 Z3330539 10:52, 1 August 2012 (EST)

Lab 3 --Z3330539 10:04, 8 August 2012 (EST)--

Lab 4 --Z3330539 09:59, 15 August 2012 (EST)--

Lab 5 --Z3330539 10:10, 22 August 2012 (EST)--

Lab 6 --Z3330539 10:08, 29 August 2012 (EST)--


Lab 1 Assessment

--Mark Hill 18:04, 10 September 2012 (EST) Please do not include spaces before your sub-headings as this will affect formatting. I have corrected Lab 1, please correct other subheadings yourself before final assessment.

Task 1

Identify the origin of In Vitro Fertilization and the 2010 Nobel Prize winner associated with this technique and add a correctly formatted link to the Nobel page.

-In Vitro Fertilization (IVF) technology is the combining/fusion of the males sperm and females egg/s outside the body, then later implanting this fertilized oocyte into the female uterus. This technique involves the regulation of the female cycle and monitoring of ovulation. This in vitro technique/concept has been present and studied for many years, with earliest recordings of such scientific research/findings; such test tube babies; occurring as early as 1950’s. The scientist who won the Nobel Prize in 2010, for his efforts and involvement in the discovery implementation of IVF techniques was the physiologist Robert Edwards. This was an honor given in the current medicine. Edwards with a fellow associate were the first recorded successful pregnancy and birth of the first and second IVF babies to be delivered in the late 1970’s and the 1980’s. Following this successful implantation, development and implantation other countries including Australia began to use this technique, for situations and individuals with fertility problems. Recent developments in this field of medicine and physiology have been on hormones involved in oocyte maturation, ovarian cycles such as follicle stimulating hormone, as well as the way in which sperm is administered in order for fertilization to occur.

Links: [1] [2]

Task 2

Identify and add a PubMed reference link to a recent paper on fertilization and describe its key findings (1-2 paragraphs).

- “Molecular Origin of Female Meiotic Aneuploidies”

This article addresses the molecular and physiological mechanisms underlying the abnormalities in pregnancy which occur as a result of aneuploidy. It discusses the disruption of the cohesion and separation of the homologues at the centromeres and the polar ends of the spindle, which can result in miscarriage and loss of pregnancy. Lack of separation of these homologues prevents the production of two separate daughter chromatids. These errors can occur either toward the end of meiosis one and also in meiosis two, and in some instances meiosis two errors can arise as a result of meiosis one errors that were not resolved. In this article, there is particular emphasis placed upon the process of female meiosis, as the major causes of errors that can lead to aneuploidy. Major errors which occur are reduced cohesion prior to separation in meiosis two, errors in trisomies, as well as premature segregation, resulting in errors of chromatid pairing and oocyte development in fertilization. Studies are being performed to examine the role, or lack of role which certain proteins play at these stages of female fertilization in order to reduce these abnormalities in conventional and IVF development, in particular in females who fall pregnant at later maternal ages. Examining the molecular mechanisms that occur when there is loss of expression of key proteins such as SMC1 alpha and beta, Scc1 and ReC8, which leads to decrease in cohesin and reduce achiasmate, ultimately leading to lack of separation of the homologues.

[3]

NB: Originally uploaded this into the discussion/my talk page, the night before, prior to moving it into my Page (z3330539).

--Mark Hill 18:04, 10 September 2012 (EST) Answers to the 2 questions are correct. I am concerned that the text in answer to question 1 appears to be from a source that has not been cited, could you please clarify this for me (for an extra mark). You have failed to transfer the citation links correctly from your discussion page to here, and the citation links located there are not correctly formatted. You have used UNSW Library links rather than the PubMed citation number or reference format as shown in the class (and below). 7/10

As a reference number link - PMID 22841925

As a formatted reference - <pubmed>22841925</pubmed>

Lab 2 Assessment

==Task 1==

Immunofluorescent FN1 and integrin on blastocytes.gif


==Task2==

A protein which is involved in the implantation process is Rac1, which is the RAS pathway related C3 botulinum toxin substrate 1. This protein expression allows for embryonic trophoblasts to invade the stromal cell layer and when activated also allows for migration and motility of the cells of the stromal layer. All of these factors lead to the promotion of implantation.

[1]

--Mark Hill 18:22, 10 September 2012 (EST) Question 1 is not correctly linked to the appropriate reference, a serious error. Therefore you have not completed the assessment correctly, I will need to delete the image if you cannot fix the referencing and alter your mark accordingly. Image is also too small to be useful and in GIF format. Question 2 is fine, please see my previous assessment comment on referencing. 6/10


As a reference number link - PMID 18838676

As a formatted reference - <pubmed>18838676</pubmed>

Lab 3 Assessment

  Task 1

Gestational age refers to the period of time, generally 14 days before the last day of the females menstrual cycle. Where as post fertilization age is the period from the point of conception/ fertilization of egg by the sperm; this mainly occurs in the middle of the menstrual cycle duration.

Gestational age is used as a clinical method of human development due to the fact that time/point of fertilization can be unknown or variable, women may have sporadic menses and ovulation, females may not be able to recall the last day of their menstrual cycle. The use of gestational age may be an approximation/generalization, however, it is more useful in reducing the variables that can occur, which are mentioned above, as last day of menstrual cycle is predominately able to be recalled by the female, and 14 days are added in order to establish room for possible variations.

References:

1. [2]

 Task 2

Somites, which are present in pairs, are derived from the paraxial mesoderm and are involved in week 4 of embryonic development. Somites progressively differentiate into sclerotome, dermatome and myotome.

Sclerotome are the central cells of the somites are are located ventromedially in relation to orientation of the notochord. Sclerotome form vertebral and bone and connective of the vertebral column and are have chondrocytes present.

Dermatome are located dorsolaterally to the notochord and involved in the differentiation into dermis and epidermis.

Finally myotome are located more dorsomedially and are involved in differentiation to skeletal muscle. This involves myoblast cells. Depending on the type, these can either lie dorsomedially and then migrate to form epaxial or hypaxial muscle groups in development.

References:

1. [3] 2. [4]

--Mark Hill 18:30, 10 September 2012 (EST) Question 1 answer is correct, but your text is confusing in relation to LMP. Question 2 describes the correct somite components, and bone, CT and skeletal muscle. But you have incorrectly identified epidermis as mesoderm in origin, this is ectodermal and not from the somite. 9/10

Lab 4 Assessment

  Task 1

The placenta within the developing fetus performs many functions, via maternal-embryonic nutrient transfer and later embryo-fetal nutrient transfer. Early in development diagnostic tests are able to be performed in order to examine if there are any abnormalities, either genetic or hematological, for example, within the growing embryo. These test and consecutive results are able to be obtained through the placenta. Some techniques are non-invasive, while others can be invasive for the mother. Two test which are performed through placenta diagnostics are a chorion biopsy (chorion villus sampling) and umbilical cord blood sampling. These two prenatal tests are both invasive and involve extraction of tissue and blood samples via injection of a thin needle into either the maternal cervix or abdominal wall in order to reach the uterus and retrieve samples from the placenta or the umbilical cord (the end which lies close to the placenta or the umbilical vein). Once samples are collected they are them examined within laboratories and analyzed for developmental abnormalities.

Though there is partial risk of miscarriage, these tests have been found to be successful in diagnosis of abnormalities such as down syndrome and pathological blood disorders such as Rh disease. The defects in early cell division in the embryo, with specific reference to down syndrome (trisomy 21) can be detected, as well as the compatibility between maternal and embryonic blood in relation to Rh disease. This gives the ability to detect whether there will be a maternal immune response, as a result of lack of blood compatibility (i.e. maternal immune response triggered post birth of first delivered child).

References:

1. [5] 2. [6] 3. [7]

 Task 2

An article which discusses the possibilities for cord stems cells to be used in therapeutically is Human umbilical cord mesenchymal stem cells and the treatment of spinal cord injury. This review article discusses the potential for umbilical cord stems cells to be used in the therapeutic treatment of spinal chord injury or disease.

Through analysis of resent findings, researchers have discovered the similar characteristic within cord stem cells that are found in bone marrow. Cord stem cells have been found to be an alternative source for mesenchymal stems cells, and therefore are seen as a promising alternative for transplantation procedures, as they are able to differentiate into numerous cells and tissues such as bone and cartilage; as well as self renewal and growth properties. Furthermore, this area of research is being considered due to the fact that there are limitations surrounding transplantation of bone marrow mesenchymal cells, such as viral contraction and cellular amount.

The spinal cord consists of a complex molecular and cellular framework, such as astrocytes, microglia cells and myelin proteins. As a result of these many constituent, when the spine is injured or diseased, treatment is difficult due to the degenerative nature/course which these problems can occur. However, through the isolation of these cord stem cells from embryonic umbilical cord, treatment may be something that soon can be highly successful with further research and clinical development. Furthermore, isolation of these umbilcal cord stems cells are more ethically supported than isolation of bone marrow mensenchymal cells.

Further research and studies are required, however, due to the fact that some attempts, methods and techniques of recent isolations have failed. Furthermore, future areas of developmental research may include longitudinal and clinical research that can further increase awareness of umbilical cord mesenchymal cell transplantation as an alternative for complex injuries, such as those to the spinal cord.

References: 1. [8] 2. [9]

--Mark Hill 16:27, 11 September 2012 (EST) Both these answers are excellent. 10/10