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Embryo Biopsy for Genetic Diagnosis

The Equine Embryo Laboratory offers our clients the ability to take a genetic sample from an embryo before it is transferred.  Embryos may be shipped to the laboratory for biopsy, after being collected from mares at the standard time (Day 7 after ovulation).

Embryo biopsy offers the owner the option of knowing the genetic makeup of an  embryo before it is transferred. By knowing this, the owner can avoid production of a foal affected with a genetic disease, or even avoid transferring an embryo carrying the gene for a disease.  In addition, the genetic analysis can determine the sex, coat color, and parentage verification of the upcoming foal.

The biopsy is performed by taking a small sample of cells from the embryo using a micromanipulator and micropipette.  The cells are collected from the area of the embryo that eventually forms the placenta.  Approximately 20 cells are collected; because the typical embryo at Day 7 contains thousands of cells, there is minimal effect on the embryo.  The collected cells are then submitted for genetic analysis.  After the cells have been collected by biopsy, the embryo may be shipped to an embryo transfer center for immediate transfer into a recipient mare, or may be vitrified (frozen) to be  transferred after the genetic analysis results are available (about one week).

The genetic analysis is >95% accurate; however, there is a slight possibility (<5%) of a gene being missed or the DNA not being read.

Embryos that have been subjected to biopsy and are transferred immediately have a normal pregnancy rate (>80% in our studies).  Vitrification decreases pregnancy rate by 10-20%.  There is no increase in pregnancy loss after transfer of biopsied embryos, and foals born from biopsied embryos are normal.