Genetic manipulation of sex differentiation and phenotype in domestic animals

In mammals, a gene based sex determination system ensures that approximatel y 50% of offspring will be of the male sex and 50% will be of the female se x. In domestic animal production systems, this ratio is not always ideal. R ecent advances in our understanding of the molecular biology of sex determi nation and differentiation, as well as in the control of gene expression an d the direct modification of animal genomes, allows us to consider methods for the direct genetic manipulation of sexual phenotype. (C) 2000 by Elsevi er Science Inc.