Rapid sexing of bovine preimplantation embryos using polymerase chain reaction: production of calves with predetermined sex under field conditions.
Two to four blastomere size biopsies were obtained from each 6-day-old embryo of zebu and crossbred cattle for sex determination. The sex of the embryos was determined with a set of bovine Y-chromosome specific primer pairs by using polymerase chain reaction. Thirty two biopsied embryos after their sex was determined, when transferred fresh to synchronized recipients, resulted in 56.2% pregnancy rate. Sixteen healthy calves were born at full term, while 2 heifers aborted at mid-term from fresh embryo transfer. Simultaneously, 44 biopsied embryos which were kept frozen, were thawed at a later date and transferred to the previously synchronized recipients, thereby leading to 24 pregnancies (54.5%). Twenty-three healthy calves were born at full term, while 1 heifer aborted at mid-term from frozen-thawed embryo transfer. The pregnancy rates from both fresh and frozen-thawed biopsied embryos were comparable with that of controls (P > 0.05). Except for a single misidentification of a male calf as a female by our PCR assay (2.6%), the phenotypic sex of all the live born calves as well as the aborted fetuses was correctly matched with the PCR detection.
Taneja
M
M
Embryo Biotechnology Laboratory, National Institute of Immunology, New Delhi, India.
Rao
K B
KB
Gangawane
S
S
Zawar
S G
SG
Totey
S M
SM
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D017931:DNA Primers; D004622:Embryo, Mammalian; D047108:Embryonic Development; D005260:Female; D008297:Male; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012732:Sex Determination Analysis; D014998:Y Chromosome
D017931:DNA Primers