User:Z3414648

From Embryology
Revision as of 10:28, 8 October 2014 by Z3414648 (talk | contribs)

Welcome to the 2014 Embryology Course!

Links: Timetable | How to work online | One page Wiki Reference Card | Moodle
  • Each week the individual assessment questions will be displayed in the practical class pages and also added here.
  • Copy the assessment items to your own page and provide your answer.
  • Note - Some guest assessments may require completion of a worksheet that will be handed in in class with your student name and ID.
Individual Lab Assessment
  1. Lab 1 Assessment - Fertilization References
  2. Lab 2 Assessment - Uploading a Research Image
  3. Lab 3 Assessment - Researching your Project Sub-Heading
  4. Lab 4 Assessment - Cord Stem Cells
  5. Lab 5 Assessment - Abnormalities
  6. Lab 6 Assessment - Group Work (As announced in the lecture, No individual assessment item for this Lab, but I do expect you to have added content to your Group project by tomorrow's Lab.)
  7. Lab 7 Assessment - Endocrine+Teeth
  8. Lab 8 - Genital
  9. Lab 9 - Peer Assessment
  10. Lab 10 - Sensory Development
  11. Lab 11 - Stem Cells
  12. Lab 12 - Stem Cells Presentation (see preparation information)
Lab 12 - Stem Cell Presentation Assessment More Info
Group Comment Mark (10)
1/8
  • Lots of effort to place article in larger context
  • Slide lay out could be improved: lots of empty space, use larger images and talk through them
  • Results presentation a bit convoluted. Try to finish discussion of each experiment with a clear conclusion.
  • Repetition of information towards the end
  • One presenter had an unprofessional style of presentation
7
2
  • Good well-structured presentation
  • Good introduction
  • Methods discussed separately. Try to avoid this, and incorporate in discussion of experiments. Not sure if technology was understood very well.
7.5
3
  • Good well-structured presentation
  • Do not discuss methods as a separate section
  • Discussion of results not always very clear, comprehension?
7.5
4
  • Good well-structured presentation
  • Lots of text on slides, improve talking through images, blow up images
  • Good discussion
8.5
5
  • Good well-structured presentation, amount of text on slides relatively good.
  • Figures too small, discussion bit convoluted
  • Slightly over time
8.5
6
  • Good comprehension and well-structured presentation.
  • Too much text on slides
  • Experiments discussed in a lot of detail. Try to be more concise and discuss aim of experiment, approach, summarize results, conclude.
  • No talking through figures
8.5
7
  • Good well-structured presentation, great introduction, inclusion of images in presentation done relatively well.
  • Methods discussed separately. Incorporate methods in discussion of the experiments in the results section.
  • Try not to depend too much on text on your slides
  • Talking through results images was not very clear, comprehension?
7.5
More Useful Links
Student Projects
Group 1 Respiratory User:Z3330991 User:Z3332339 User:Z3333429 User:Z3372817
Group 2 Renal User:Z3463310 User:Z3465141 User:Z3465654 User:Z5030311
Group 3 Gastrointestinal User:Z3414515 User:Z3375627 User:Z3415141 User:Z3415242
Group 4 Genital User:Z3415716 User:Z3416697 User:Z3417458 User:Z3417753
Group 5 Integumentary User:Z3417796 User:Z3417843 User:Z3418340 User:Z3418488
Group 6 Endocrine User:Z3418702 User:Z3418837 User:Z3418698 User:Z3414648
Group 7 Neural User:Z3418981 User:Z3419587 User:Z3422484 User:Z3374116
Group 8 Musculoskeletal User:Z3418779 User:Z3418718 User:Z3418989
Student Projects Fetal Development of a specific System.
2014 Course: Week 2 Lecture 1 Lecture 2 Lab 1 | Week 3 Lecture 3 Lecture 4 Lab 2 | Week 4 Lecture 5 Lecture 6 Lab 3 | Week 5 Lecture 7 Lecture 8 Lab 4 | Week 6 Lecture 9 Lecture 10 Lab 5 | Week 7 Lecture 11 Lecture 12 Lab 6 | Week 8 Lecture 13 Lecture 14 Lab 7 | Week 9 Lecture 15 Lecture 16 Lab 8 | Week 10 Lecture 17 Lecture 18 Lab 9 | Week 11 Lecture 19 Lecture 20 Lab 10 | Week 12 Lecture 21 Lecture 22 Lab 11 | Week 13 Lecture 23 Lecture 24 Lab 12
Student Projects - Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6 | Group 7 | Group 8 | Moodle

PubMed

Lab Attendance

Lab 2

--Z3414648 (talk) 11:11, 20 August 2014 (EST) Lab 2 I did not put my signature in my lab attendance last week however I did attend. The week 2 lab involved two guest researches discussing meiosis in mammalian oocytes and age-related vulnerability and the reproductive technology revolution.

Lab 3

--Z3414648 (talk) 11:12, 20 August 2014 (EST) Lab 3

Lab 4

--Z3414648 (talk) 11:48, 27 August 2014 (EST)

Lab 5

--Z3414648 (talk) 11:10, 3 September 2014 (EST)

Lab 6

--Z3414648 (talk) 11:39, 10 September 2014 (EST)

Lab 7

--Z3414648 (talk) 12:07, 17 September 2014 (EST)

Lab 8

--Z3414648 (talk) 11:04, 24 September 2014 (EST)

Online Assignment 1

Article 1

<pubmed>24934154</pubmed>

This article from PubMed explores the role of the ZP2 receptor and protein in female mice fertility and species-specific nature of the fusion of spermatozoa and oocyte during successful fertilisation. ZP2 is a glycoprotein found in a region of the extracellular oocyte-surrounding zona pellucida . Polyspermy is an abnormal and detrimental process where membrane fusion occurs between one oocyte and more than one spermatozoa. It is inefficient for more than one spermatozoa to bind to the oocyte because only one male and female gamete are required for successful fertilisation. The authors of this article used gamete samples from both mice and human origin to illustrate their findings.

The authors used various materials and scientific methods in order to achieve their results. There were extensive, complex and repetitive biochemical and transgenic variations made in order to manipulate the gene expression and protein synthesis occurring in the test subjects, in this case mice. In order to control which cells could be genetically modified to express human or mice ZP2 protein, they scientists needed to first produce transgenic mouse lines from embryonic stem cells that had not yet differentiated into any of the ZP1, ZP2, ZP3 or ZP4. They created Bacterial Artifical Chromosomes carrying either the mouse or human form of the ZP2 gene and these were transformed into bacterial cells containing the gamma prophage. The recombinants could be identified by growing the transformed cells on minimal media with galactose. Once the transgenic mice line was established, they were genotyped using TP2 specific primers in extensive PCR reactions. The eggs and embryos were examined under the microscope and the scientists carried out immunohistochemistry. They examined the fertility of the females with and without the ZP2 binding ability through mice and human sperm assays. They also experimented with in vitro fertilisation of the female mice oocyte with mice sperm and then human sperm.

These scientists accumulated results which revealed with following things. The transgenic female mice that did not express ZP2 in their zona pellucida where sterile. Female mice that were genetically modified to express the four human ZP proteins (ZP1, ZP2, ZP3 and ZP4) were recognised by human sperm to carry our successful fertilisation. However the female mice that did not express the human ZP2 protein did not attract the human sperm for fertilisation. This illustrated the species-specific gamete fusion that occurs in human fertilisation.


Article 2

<pubmed>23909991</pubmed>

This journal article from PubMed compares the nature of embryo hatching between two different types of artificial fertilisation of a female gamete: in vitro fertilisation (IVF) and intracytoplasmic sperm insemination (ICSI). 'Hatching' is a term given to the process that occurs at around day 6 of embryo development, post zygote production, and it is where the blastocyst containing the maternal and paternal pronulei escapes the zona pellucida. In vitro fertilisation is where female follicles are isolated from the ovary and are exposed to spermatozoa. The spermatozoa acrosomal head naturally fuses to the zona pellucida of the female follicle and from there, there is no more external manipulation. The genetic material from the sperm mixes with the genetic material of the occyte resulting in fertilisation and a zygote. In intracytoplasmic sperm insemination, a fine needle is used to inject the sperm through the zona pellucida directly into the oocyte.

These scientists performed a study in a fertility clinic and carried out in vitro fertilisation, embryo culture and embryo grading in order to obtain the results they wanted. Oocytes were inseminated either via IVF or ICSI and then the embryos were cultured and tested for successful fertilisation using an embryoscope. The grade the embryos were given was based on the size of the blastocele cavity and the cohesiveness of the inner cell mass. The embryos with the best morphology were used for further testing. The embryoscope took images every 20 minutes and this enabled the researchers to compare the nature of embryo hatching from the two different types of artificial fertilisation techniques.

The results from these experiments showed there were two main types of spontaneous hatching which were specific for the two types of artificial fertilisation. One type of hatching was initial finger like projections reaching out of the zona pellucida before eventually the blastocyst emerged. The other type was spontaneous complete hatching out of the zona pellucida where the embryo completely ruptured through without the initial projections. The first type was mainly seen with the ICSI technique and the sudden rupture hatching was seen with the IVF technique.


--Mark Hill These are good summaries of these 2 research articles (5/5)

Online Assignment 2

Cleavage stage embryo


Online Assignment 3

Pituitary gland

<pubmed>10.1016/j.acthis.2014.04.003</pubmed>

<pubmed>10.1371/journal.pone.0004815</pubmed>

<pubmed>10.1371/journal.pone.0004513</pubmed>


Thyroid

<pubmed>10.1371/journal.pone.0080801</pubmed>

<pubmed>10.1530/JOE-14-0025</pubmed>

<pubmed>10.1371/journal.pone.0016752</pubmed>


--Mark Hill You have included the references but not formatted the links correctly. (4/5) See Help:Reference Tutorial

Online Assignment 4

Therapeutic Cord Stem Cell Use

The article written by S. Gopinath et al. looks into the therapeutic use of human umbilical cord blood (hUCB)-derived stem cells in reversing pathological hypertrophy of heart tissue in rats. It is an extensive research paper that uses the pre-existing knowledge that cord stem cells are pluripotent and have the potential to differentiate into any tissue of the body. Using this they investigated the ability for hUCB-derived stem cells to reverse the pathological hypertrophy that occurs when rats are induced with doxorubicin (DOX). Doxorubicin is a cancer-treating drug but is also known to induce cardiac hypertrophy. Cardiac hypertrophy involves the increase of size of cardiomyocytes, increased protein synthesis, increased interstitial fibrosis and higher organisation of a sarcomere. However there is also increased frequency of apoptosis that is dangerous considering myocytes have a limited self-renewal capacity. Hence if hUCB-derived stem cells have a cardiomyogenic potential, they could be used to reverse heart failure conditions.


One key result that came about during this investigation was that after 24 hours of co-culture of normal rat cardiomyocytes and hUCB-derived stem cells, the structure of the red stained hUCB-cells began to look like myocytes. Immunocytochemistry staining showed that these new myocytes stained positive for molecules found in normal myocytes including connexion 43 and N-cadherin. There was also a clear image of striated cardiac α-actinin. Upon physical examination, the researchers found that these new myocytes beat in a strong, synchronised manner and also exhibited tight electrical coupling with the normal rat myocytes. Another finding was that hUCB-derived stem cells were able to decreases the apoptotic activity of DOX induced cardiac cells. This was indicated by the decrease expression of apoptotic proteins like caspase-9 and caspase-3 from the initially highly active apoptosis in the DOX-induced cells.


Finally, the researchers were able to prove a significant finding involving the ability for hUCB-derived stem cells to reverse the pathological hypertrophy induced by the DOX. Part of the reason for this result was that the hUCB-derived stem cells were replacing the dead myocytes and there was increased paracrine secretion of IGF-1. This is significant because IGF-1 (insulin-like growth factor 1) is known to increase cell proliferation and inhibit apoptosis.

<pubmed>20382121</pubmed>

There are a number of developmental vascular "shunts" present in the embryo that are closed postnatally. Identify these shunts and their anatomical location.

1. Foramen ovale: a shunt in the aortic arch is present in the embryo meaning the blood flow bypasses the pulmonary circulation. The blood can flow from the right atrium to the left atrium without going via the pulmonary circuit.

2. Ductus venosus: a shunt that exists between the left umbilical vein and the inferior vena cava. It mean the oxygenated blood from the placenta bypasses the liver on the way to the embryo

3.Ductus arteriosus: a shunt that exists between the proximal descending aorta and the pulmonary artery. This is important in allowing the blood to run from the right ventricle to the aorta without entering the prenatal fluid-filled lungs.

<pubmed>21513818</pubmed>


Online Assignment 5

Congenital Pulmonary Airway Malformation

Congenital Pulmonary Airway Malformation (CPAM) is an abnormality that comes as a result of abnormal respiratory system development from week 4 to 10 of gestation. There are varying classes of CPAM depending on the level of differentiation of alveoli, the functional unit of the respiratory system, and the location of the abnormality. Although not completely understood, it is believed that this abnormality arises from unusual lung budding of the foregut endoderm during week 4 to 5 of development.[1] Depending on the malformation observed, the embryological timing can help explain the deformity. Type I CAMP is where there is a localised cystic lesion in a lobe of the lung with pseudostratified ciliated columnar epithelium and relatively well differentiated alveolar cells. [2] This suggests the malformation occurred during week 7 to 10 which is when bronchial cartilage and smooth muscle form in the fetus.


Congenital Pulmonary Airway Malformations usually involve cystic changes in terminal bronchioles of the lung and are usually accompanied by recurrent pulmonary infections, lung abscesses and intra and extra lobar sequestration. They are usually recognised in the neonate within the first 2 years of life however they can also lie unobserved until later in life. CPAM in an adult can cause massive hemoptysis (coughing up blood) and respiratory distress but rarely causes symptoms like fever, headache, weight loss or chest pain that are typical of other respiratory disorders like pneumonia. If the malformation is isolated to a small part of a lobe, it can be removed surgically but type III CPAM has poor prognosis as it usually involves large lesions that are dispersed throughout the majority of a lobe of the lung.[2]


Another theory on the cause of Congenital Pulmonary Airway Malforamtion is arrested development of the bronchial tree during week 6 to 7 of lung development. Furthermore it has been found that the thyroid transcription factor 1 (TTF1) plays a role in lung epithelium differentiation and lung development. It is found only in the lung, thyroid and in some parts of the brain so mutation or deletion to the gene coding for TTF1 could contribute to malformation of lung epithelium resulting in CPAM. [3]


  1. <pubmed>10.3109/15513815.2010.547556</pubmed>
  2. 2.0 2.1 <pubmed>24672262</pubmed>
  3. <pubmed>10.4187/respcare.00727</pubmed>

Online Assignment 6

I have found a paper written in 2009 by a group of researchers from the University of California who have investigated the role of DNA methyltransferase 1 (Dnmt1) in pancreas development. Their paper Loss of Dnmt1 catalytic activity reveals multiple roles for DNA methylation during pancreas development and regeneration looks at the role of Dnmt1 in the development of the endodermal originating endocrine, duct and acinar cells of the pancreas. It uses a deductive method involving acquired Dnmt1 mutant zebra fish and looking at which pancreatic cells have inhibited, improved or unchanged growth and development.


This paper is useful in consolidating our understanding of the control of various endodermal cells involved in pancreas growth and function. Dnmt1 is an enzyme that controls gene regulation and helps maintain chromosomal integrity. This paper found that in the early stages of pancreas development, Dnmt1 is a critical part of acinar cell development but not for beta cells or pancreatic duct cells. Their investigation using Zebrafish as a model showed that without this enzyme, the pancreas formed and then degenerated 84h post fertilization (hpf). With further investigation, they found that by 100hpf, almost all the acinar cells had undergone apoptosis but the endocrine and pancreatic duct cells still maintained integrity and remained functional.


Although this paper uses zebrafish rather than humans to investigate pancreas development, it still reveals a relative timescale of the organ development. It also highlights the complex nature of endocrine organ development and how many enzymes are involved in assuring correct growth takes place. [1]


  1. <pubmed>10.1016/j.ydbio.2009.07.017</pubmed>


Embryonic layers and tissues contributing to developing teeth:

  • Ectoderm contributes to tooth enamel epithelium
  • Neural crest derived mesenchyme contributes to dentin and pulp of the teeth
  • The teeth develop around the stomodeum which is the origin of the oral cavity
  • Some argument around vertebrates that have pharyngeal teeth, suggesting there is a pharumgeal endodermal origin involved as well, however it isn’t as thoroughly understood.

<pubmed>10.1038/nature07304</pubmed>

Online Assessment 7

Embryonic Development of the Human Ovary

Human gonad development begins around week 5 of embryological growth and the sex of the fetus depends on the X or Y chromosomal contribution from the male and female gametes at fertilization. Until around week 10, the human gonads are considered to be bipotential meaning they have the ability to differentiate into male testes or female ovaries. [1] Gonad development is often referred to as urogenital development since it is closely related to the urinary system growth. Around week 4 the primordial germ cells are established at the site of umbilical vesicle near the origin of the allantois. In week 5 there is a thickening of the mesothelium on the medial side of the mesonephros which is the primitive kidney.


During embryonic folding, the dorsal part of the umbilicus is incorporated into the embryo and by week 5, there is migration of the germ cells to the genital ridge. By week 6, there is proliferation of the epithelium and mesenchyme at the genital ridge that results in finger-like projections of epithelium forming genital cords producing an external cortex and internal medulla. The primordial germ cells migrate into the mesenchyme of the genital cords and this is controlled by various genes like stella and fragilis. In addition to the genital folds, by week 6 there are two types of genital ducts: mesonephric and paramesonephric. The mesonephric contributes to male gonad development whereas the paramesonephric contributes to female gonad development.


The paramesonephric duct is also known as the Mullarian duct and in men there is an anti-mullarian gene that when switched on is responsible for the degradation of this duct. The Mullarian duct is a result of the invagination of the coelomic epithelium through the mesonephros. [2] The cranial end of the duct opens to the peritoneal cavity whereas the caudal end runs parallel and lateral to the Wolfian tube until it crosses over ventrally and fuse to form a y shaped uterovaginal primordium, the eventual uterus and vagina. An XX genotype results in a female embryo and this is because testosterone is not produced, resulting in lack of maintencance of the mesonephric duct, no expression of anti-mullarian hormone hence maintenance of the paramesonephric duct. From week 10 onwards there is further gonad and external genital growth forming the ovaries, uterus and vagina.


Historic Image of Human Urogenital Development

Fig. 1109. Urogenital Sinus of Female Human Embryo of 8.5 to 9 weeks old

Gray1109.jpg (From model by Keibel)

The Müllerian Ducts (Paramesonephric Ducts)


  1. <pubmed>10.1038/nrendo.2014.163</pubmed>
  2. <pubmed>10.1016/j.ydbio.2007.03.027</pubmed>


|- | The Developing Human, 8th edn.jpg | Moore, K.L. & Persuad, T.V.N. (2008). The Developing Human: clinically oriented embryology (8th ed.). Philadelphia: Saunders.

The following chapter links only work with a UNSW connection and can also be accessed through this UNSW Library connection.


Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)


The image is from the book Grays Anatomy from 1918 which can be accessed by the following link:

Links: Uterus Development | Gray's Urogenital Images