AsianScientist (May 17, 2018) – A research group in Japan has used live-cell imaging to identify genetic abnormalities in bovine in vitro fertilized (IVF) embryos. Their findings, published in Scientific Reports, could lead to improved IVF success rates in cows.
IVF embryo transfer has become an important innovation in the agricultural sector. In fact, approximately half of all bovine embryos produced worldwide were derived from IVF.
However, the pregnancy success rate of IVF embryos transplanted into recipients remains low. Embryo quality is assessed by morphological grading on days 7-8 post-insemination, as recommended by the International Embryo Technology Society (IETS). Only 30-50 percent of the embryos judged as transferable by this grading result in pregnancy. Therefore, novel technology for non-invasively and reliably selecting viable IVF embryos is required.
In this study, a research group led by Dr. Satoshi Sugimura of the Tokyo University of Agriculture and Technology has successfully identified bovine IVF embryos bearing chromosomal abnormalities by long-term live-cell imaging with fluorescence confocal microscopy.
Chromosomal abnormalities were detected by injection of mRNA encoding histone H2B-mCherry and EGFP-α-tubulin. The live-cell imaging revealed that about half of embryos judged as morphologically transferable by IETS criteria had nuclear or chromosomal abnormalities, such as an abnormal number of pronuclei and abnormal chromosome segregation, which may lead to abortion. The researchers reported that two cows receiving embryos without any nuclear or chromosomal abnormalities got pregnant.
The article can be found at: Yao et al. (2018) Live-cell Imaging of Nuclear–chromosomal Dynamics in Bovine in vitro Fertilized Embryos.
Source: Tokyo University of Agriculture and Technology; Photo: Shutterstock.
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