2015 Group Project 1: Difference between revisions

From Embryology
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'''Polar bodies''' are small cells formed during the meiotic reductive division of the oocyte. they contains complementary choromosomes (to the mature oocyte) and small amount of cytoplasmic segregation<ref><pubmed> 24949971 </pubmed></ref>.  [[File:Early zygote labelled.jpg|250px|thumb|an early human zygot <ref name = earlyzygot>Hill, M.A. (2015) Embryology Early zygote labelled.jpg. Retrieved October 16, 2015, from https://embryology.med.unsw.edu.au/embryology/index.php/File:Early_zygote_labelled.jpg</ref>]]
'''Polar bodies''' are small cells formed during the meiotic reductive division of the oocyte. They contain complementary chromosomes (to the mature oocyte) and small amount of cytoplasmic segregation<ref><pubmed> 24949971 </pubmed></ref>.  [[File:Early zygote labelled.jpg|250px|thumb|an early human zygote <ref name = earlyzygot>Hill, M.A. (2015) Embryology Early zygote labelled.jpg. Retrieved October 16, 2015, from https://embryology.med.unsw.edu.au/embryology/index.php/File:Early_zygote_labelled.jpg</ref>]]


* Polar body 1 is formed and released during ovulation. it contains a diploid set of chromosomes.  
* Polar body 1 is formed and released during ovulation. It contains a diploid set of chromosomes.  
* Polar body 2 is formed during fertilization and can be identified in the zygote. it contains a haploit set of chromosomes.   
* Polar body 2 is formed during fertilization and can be identified in the zygote. It contains a haploid set of chromosomes.   
* Both polar bodies are unable to be fertilized and disintegrate eventually
* Both polar bodies are unable to be fertilized and disintegrate eventually.


Due the unique feature of polar bodies, which can provide beneficial information about the genetic background of the oocyte without potentially destroying it, polar body biopsies have been applied in preimplantation genetic diagnosis to detect inheritable chromosomal or genetic abnormalitiesg. More recently, the new roles of polar bodies in assisted reproductive technology are single-cell sequencing of the polar body genome to deduce the genomic information of its sibling oocyte and the polar body transfer to prevent the transmission of mtDNA-associated diseases <ref><pubmed> 25472922 </pubmed></ref>.
Due the unique feature of polar bodies, which can provide beneficial information about the genetic background of the oocyte without potentially destroying it, polar body biopsies have been applied in preimplantation genetic diagnosis to detect inheritable chromosomal or genetic abnormalities. More recently the role of polar bodies in assisted reproductive technology are: single-cell sequencing of the polar body genome to deduce the genomic information of its sibling oocyte and polar body transfer to prevent the transmission of mtDNA-associated diseases <ref><pubmed> 25472922 </pubmed></ref>.


The '''advantages''' of polar body transfer has been reported as<ref><pubmed> 25472922 </pubmed></ref>:
The '''advantages''' of polar body transfer have been reported as<ref><pubmed> 25472922 </pubmed></ref>:


* Polar body 1 and 2 contain minimunmitochondria but carries the entire genome.
* Polar body 1 and 2 contain minimum mitochondria but carries the entire genome.
* Polar body 1 and 2 are seperate from the oocyte thus it can be easily manipulated without damage to the chromosome.
* Polar body 1 and 2 are separate from the oocyte, thus can be easily manipulated without damage to the chromosome.
* each donor will have three offers (polar body 1, body 2, maternal pronucleus), which significant increase the efficiency of using donor egg.
* each donor will have three offers (polar body 1, body 2, maternal pronucleus), which significant increase the efficiency of using donor egg.


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Polar body transfer has been adopted on mice model to prevent the transmission of mtDNA variants. They also compare the effects of different types of germline genome transfer, including spindle-chromosome transfer, pronuclear transfer, and first and second polar body transfer, in mice. Their pre-clinical model indicate that polar body transfer has better potential in preventing the inheritance of mitochondrial diseases<ref><pubmed> 24949971 </pubmed></ref>.
Polar body transfer has been adopted in mice models to prevent the transmission of mtDNA variants. They also compare the effects of different types of germline genome transfer, including spindle-chromosome transfer, pronuclear transfer, and first and second polar body transfer, in mice. Their pre-clinical model indicate that polar body transfer has better potential in preventing the inheritance of mitochondrial diseases<ref><pubmed> 24949971 </pubmed></ref>.
The other group coupled Polar body transfer  with Pronuclei transfer or Spindle-choromosome transfer on mice model which increased the yield of reconstructed embryos with low mtDNA carryover. <ref><pubmed> 25573721 </pubmed></ref>
The other group coupled Polar body transfer  with Pronuclei transfer or Spindle-choromosome transfer on a mice model which increased the yield of reconstructed embryos with low mtDNA carryover. <ref><pubmed> 25573721 </pubmed></ref>


==Other Approaches==
==Other Approaches==

Revision as of 05:38, 23 October 2015

2015 Student Projects 
2015 Projects: Three Person Embryos | Ovarian Hyper-stimulation Syndrome | Polycystic Ovarian Syndrome | Male Infertility | Oncofertility | Preimplantation Genetic Diagnosis | Students
2015 Group Project Topic - Assisted Reproductive Technology
This page is an undergraduate science embryology student and may contain inaccuracies in either description or acknowledgements.

Three Person Embryos

Three Person Embryos are embryos from oocytes that contain maternal and paternal DNA, and mitochondria from a third donor. Collectively, the techniques for the creation of Three Person Embryos are referred to as Mitochondrial Donation or Mitochondrial replacement-assisted IVF. Mitochondrial donation is used for the prevention of maternal inheritance of Mitochondrial disorders that occur due to the mutation of mitochondrial DNA (mtDNA). It is considered a germ-line therapy, with the donated mitochondria being passed maternally to the next generation. Because of this it has generated debate in the media and scientific community over the ethics of its use, since the first techniques were developed in the 1980s. Recently, with the development of safer techniques, the United Kingdom and United States have begun the process of legalizing its clinical use.


<html5media width="560" height="315">https://www.youtube.com/embed/0Zs2KntZ7vU</html5media>

Teenage Girl Has Three Biological Parents [1]

History