2015 Group Project 1: Difference between revisions

From Embryology
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==Spindle-Chromosome Transfer==
==Spindle-Chromosome Transfer==


Spindle-choromosome transfer is a modified cloning technique which transfers the meiotic spindle and attached chromosomes (spindle-chromosome complex, SCC) from one mature oocyte to another to select for a cytoplasm or mtDNA background <ref><pubmed>25444504</pubmed></ref>. Comparing to cytoplasmic transfer, the '''advantage''' of spindle transfer is the reduction in heteroplasmy risk, thus offering a better reproductive option to prevent mtDNA disease transmission in affected families <ref><pubmed>23103867</pubmed></ref>. This technology has been used to generate both cattle and mice after subsequent fertilization (Bai et al, 2006, Bao et al, 2003, Wakayama et al, 2004 and Wang et al, 2001), and has generated live monkeys (Macaca mulatta) after sperm injection <ref name=PMID25573721/>. Spindle transfer between human oocytes has also result in blastocyst development and embryonic stem cell derivation with very low levels of heteroplasmy <ref><pubmed> 25973765 </pubmed></ref>.  
Spindle-choromosome transfer is a modified cloning technique which transfers the meiotic spindle and attached chromosomes (spindle-chromosome complex, SCC) from one mature oocyte to another to select for a cytoplasm or mtDNA background <ref><pubmed>25444504</pubmed></ref>. Comparing to cytoplasmic transfer, the '''advantage''' of spindle transfer is the reduction in heteroplasmy risk, thus offering a better reproductive option to prevent mtDNA disease transmission in affected families <ref name=pmid23103867><pubmed>23103867</pubmed></ref>. This technology has been used to generate both cattle and mice after subsequent fertilization (Bai et al, 2006, Bao et al, 2003, Wakayama et al, 2004 and Wang et al, 2001), and has generated live monkeys (Macaca mulatta) after sperm injection <ref name=PMID25573721/>. Spindle transfer between human oocytes has also result in blastocyst development and embryonic stem cell derivation with very low levels of heteroplasmy <ref><pubmed> 25973765 </pubmed></ref>.  




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===Current Research===
===Current Research===


Currently, researchers at Newcastle University in the United Kingdom are collaborating with the Oregon researchers who successfully generated the first primate model in 2009. They are now testing the maternal spindle transfer technique on human oocytes. ''Fertilization rate in ST oocytes (73%) was similar to controls (75%); however, a significant portion of ST zygotes (52%) showed abnormal fertilization as determined by an irregular number of pronuclei. Among normally fertilized ST zygotes, blastocyst development (62%) and embryonic stem cell isolation (38%) rates were comparable to controls. All embryonic stem cell lines derived from ST zygotes had normal euploid karyotypes and contained exclusively donor mtDNA''. Thus they concluded that the mtDNA can be efficiently replaced in human oocytes, although some ST oocytes displayed abnormal fertilization<ref><pubmed> 23103867</pubmed></ref>.
Currently, researchers at Newcastle University in the United Kingdom are collaborating with the Oregon researchers who successfully generated the first primate model in 2009. They are now testing the maternal spindle transfer technique on human oocytes. ''Fertilization rate in ST oocytes (73%) was similar to controls (75%); however, a significant portion of ST zygotes (52%) showed abnormal fertilization as determined by an irregular number of pronuclei. Among normally fertilized ST zygotes, blastocyst development (62%) and embryonic stem cell isolation (38%) rates were comparable to controls. All embryonic stem cell lines derived from ST zygotes had normal euploid karyotypes and contained exclusively donor mtDNA''. Thus they concluded that the mtDNA can be efficiently replaced in human oocytes, although some ST oocytes displayed abnormal fertilization<ref name=pmid23103867/>.





Revision as of 19:21, 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.


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Teenage Girl Has Three Biological Parents [1]

History