Identification of breed-specific DNA polymorphisms for a simple and unambiguous screening system in germline chimeric...

In the chicken, Dominant white is one of the major loci affecting feather color. Germline chimeric chickens are identified by testcross analysis using this genetic marker. The testcross, however, is a time-consuming and laborious procedure, resulting in the need for a faster and simpler molecular method. A recent study showed that Dominant white was exclusively associated with a 9-bp insertion in the PMEL17 gene. We searched for breed-specific sequence polymorphisms in the PMEL17 gene among White Leghorn (WL) (white feather), Korean Ogol Chicken (KOC) (black feather), and Barred Plymouth Rock (grayish-white, each feather regularly crossed with parallel blue-black bars). In addition to the 9-bp insertion, WLs and KOCs have unique bases in single nucleotide polymorphisms (SNPs) at the 1,777th and 3,118th bases in the PMEL17 gene. To detect these sequence polymorphisms, allele-specific polymerase chain reaction (AS-PCR) was performed, which successfully distinguished the different breeds. We confirmed the ability of the AS primers to detect germline chimerism. This simple method can be widely used for the screening of germline chimeric chickens.