Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Genetics. 1997 Dec;147(4):1863-72.

Nucleotide sequence evolution at the kappa-casein locus: evidence for positive selection within the family Bovidae.

Author information

  • 1Department of Veterinary Pathobiology, Texas A & M University, College Station 77843-4467, USA.

Abstract

Kappa-casein is a mammalian milk protein involved in a number of important physiological processes. In the gut, the ingested protein is split into an insoluble peptide (para kappa-casein) and a soluble hydrophilic glycopeptide (caseinomacropeptide). Caseinomacropeptide is responsible for increased efficiency of digestion, prevention of neonate hypersensitivity to ingested proteins, and inhibition of gastric pathogens. Variation within this peptide has significant effects associated with important traits such as milk production. The nucleotide sequences for regions of kappa-casein exon and intron four were determined for representatives of the artiodactyl family Bovidae. The pattern of nucleotide substitution in kappa-casein sequences for distantly related bovid taxa demonstrates that positive selection has accelerated their divergence at the amino acid sequence level. This selection has differentially influenced the molecular evolution of the two kappa-casein split peptides and is focused within a 34-codon region of caseinomacropeptide.

PMID:
9409842
[PubMed - indexed for MEDLINE]
PMCID:
PMC1208352
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk