TYPING OF X-CHROMOSOMES BEARING TABBY ALLELE IN MOUSE PREIMPLANTATIONEMBRYOS BY DETECTION OF A MICROSATELLITE MARKER

Tabby (Ta) is a semidominat allele of the locus on the mouse X chromos ome, which causes a characteristic coat pattern and developmental defe cts in endocrinic glands. To establish a method for identifying the X chromosome bearing the Ta allele in early preimplantation embryos, we performed PCR amplification of an X chromosomal microsatellite marker locus from preimplantation embryos obtained from mating between XO fem ale and XY male mice. The microsatellite marker locus was shown to be polymorphic between X chromosomes bearing the Ta and wild-type alleles . The amplification of the marker locus from early preimplantation emb ryos demonstrated that the Ta locus can be correctly typed by this met hod from embryos as little as 2 cells.