Localization of the α-S2-casein gene (CASAS2) to the homoeologous cattle, sheep, and goat chromosomes 4 by in situ hybridization

Abstract

The Α-S2-casein gene (CASAS2) has been mapped to the homoeologous cattle, sheep, and goat chromosomes 4 and to the long arm of a bovine chromosome translocation, t(4;8), using nonradioactive in situ hybridization and simultaneous fluorescent R-banding. The t(4;8) has been characterized by GTG-, GBG-, and RBG-banding and by silver staining of nucleolus organizer regions. These results confirm the previous (ISCNDA, 1989) localization of the casein gene group to chromosome 4 of cattle, sheep, and goats. We propose that the discrepancy between our results and earlier assignments of the casein gene group to chromosome 6 of cattle and sheep can be explained by the fact that the chromosome identified as No. 6 in the Reading Conference (1976) report was renamed chromosome 4 in the ISCNDA (1989) standardized karyotype of both species.

Application of Milk Proteins Genetic Polymorphism for Selection and Breeding of Dairy Cows in Bulgaria

“…The four casein genes are localized in a 250 kb cluster (Ferretti et al, 1990;Threadgill & Womack, 1990) situated in the Chromosome 6 (Hayes et al, 1993a;Popescu et al, 1996). Their order is CSN1S1, CSN2, CSN1S2 and CSN3.…”

Mapping quantitative trait loci for milk production and genetic polymorphisms of milk proteins in dairy sheep

“…cattle, sheep and goats [9,30]. Two α s1 -cas variants, "Normal" and "Welsh" were first detected [31] followed by five variants (A to E) [16].…”

Casein Haplotype Structure in Five Italian Goat Breeds

“…In goats, the entire casein gene cluster region spans about 250 kb on chromosome 6 (Hayes et al, 1993). Furthermore, CSN1S1 and CSN2 are only 12 kb apart and are convergently transcribed (Leroux and Martin, 1996).…”