Duplication polymorphisms in exon 4 of κ-casein gene in yak breeds/populations.
The objective of this study was to compare 12 bp-duplication polymorphisms in exon 4 of the κ-casein gene among 3 breeds/populations of yak (Bos grunniens). Genomic DNA was extracted from yak blood or muscle samples (N = 211) and a partial sequence of exon 4 of κ-casein gene was amplified by polymerase chain reaction. A polyacrylamide gel electrophoresis assay of the products (169 bp) revealed 2 variants. These variants differed in a 12-bp duplication of the nucleotide sequence corresponding to amino acids 147-150 (Glu-Ala-Ser-Pro) or 148-151 (Ala-Ser-Pro-Glu). The genotype frequency and gene frequency of the 2 κ-casein variants differed among the 3 yak breeds/populations. The long form of the κ-casein gene was the predominant allele, and the Jiulong yak showed the highest frequency of the short form variant of the κ-casein gene. In addition, 2 nucleotide differences resulting in amino acid substitutions were also identified in yaks. These results are significant for designing a breeding strategy to improve the genetic makeup of yak herds.
S
S
Pingcuo
J
J
Gao
Institute of Animal Science and Veterinary Medicine of Ganzi Prefecture, Kangding, Sichuan, China.
Z R
ZR
Jiang
College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
S Y
SY
Jin
College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
C Y
CY
Fu
Institute of Animal Science and Veterinary Medicine of Ganzi Prefecture, Kangding, Sichuan, China.
X
X
Liu
College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
L
L
Huang
Y C
YC
Zheng
D000818:Animals; D001483:Base Sequence; D001947:Breeding; D002364:Caseins / Q000235:genetics*; D002417:Cattle; D004587:Electrophoresis, Agar Gel; D005091:Exons / Q000235:genetics*; D020440:Gene Duplication; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D002364:Caseins