Frequencies of Genotypes and Alleles
Frequency distributions for genotypes and alleles var- ied among breeds and lines. For PRLpro2 (Table 6), the White Leghorn was homozygous +/+, whereas the Beijing-you and the Silkie were homozygous −/−. The remaining stocks exhibited both + and − alleles with a very high frequency of − in the Shou-guang. As shown in Table 7 for PRLR3, the locus was fixed for genotype A in the White Leghorn, and genotype A was more frequent than G in the other breeds except for the Hy-Line. The genotype TG at PRLR6 was fixed for the White Leghorn and more frequent than CA in the Hy-Line and Avian stocks (Table 7). The Chinese breeds shared approxi- mately equal frequencies.