DETERMINATION OF THE ZYGOSITY OF EV21-K IN LATE-FEATHERING MALE WHITELEGHORNS USING THE POLYMERASE CHAIN-REACTION

The dominant sex-linked late-feathering (LF) gene, K, is of commercial importance for sex determination at hatch. Knowledge of the zygosity of sequences associated with K would enable breeders to more efficient ly select homozygous grandparent LF males on the maternal side of the standard feather-sex cross because all of their progeny would be LF, w hereas only half of the progeny from heterozygous grandparent males wo uld be LF. A specific, polymerase chain reaction (PCR) assay is descri bed that distinguishes White Leghorn K/K males from K/k+ males and obv iates the need to raise all LF grandparent males to sexual maturity. B ecause the Z chromosome of some LF broiler breeders have, in addition to the endogenous virus gene, ev21, the wild type allele, which is ter med the unoccupied repeat b (URb), this approach may not be applicable to some broiler lines.