Analysis of longissimus thoracis protein expression associated with variation in carcass quality grade and marbling of beef cattle raised in the pacific northwestern US.

Research paper by Kara J KJ Thornton, Kalyan C KC Chapalamadugu, Eric M EM Eldridge, Gordon K GK Murdoch

Indexed on: 25 Jan '17Published on: 25 Jan '17Published in: Journal of Agricultural and Food Chemistry


Longissimus thoracis (LD) samples from 500 cattle were screened for protein expression differences relative to carcass quality grade. The LD of the top 5% (low prime and high choice, HQ) and bottom 5% (low select, LQ) carcasses were analyzed using two-dimensional difference gel electrophoresis and western blot. Following initial screening, 11 candidate proteins were selected for Western blot analyses. Differentially expressed proteins were clustered into 4 groups: (1) heat shock proteins and oxidative protection, (2) sarcomeric proteins: muscle maturity and fiber type, (3) metabolism and energetics and (4) miscellaneous proteins. Proteins from groups 1 and 2 were greater in HQ carcasses. Alternatively, increased quantities of proteins from group 3 were observed in LQ carcasses. Proteomic differences provide insights into pathways contributing to carcass quality grade. A deeper understanding of the physiological pathways involved in carcass quality grade development may allow producers to employ production practices that improve quality grade.