Study Examines Effects of Gene Expression on Turkey Meat Quality27 June 2013
US - Researchers have found differences in gene expression associated with pale, soft exudative (PSE) meat in turkeys, leading to the prospect of breeding programmes to eliminate this meat quality issue in future.
A team of researchers from the US has examined the differences in gene expression in turkeys that affect meat quality.
In response to high consumer demand, turkeys have been intensively selected for rapid growth rate and breast muscle mass and conformation. The success in breeding selection has coincided with an increasing incidence of pale, soft, and exudative (PSE) meat defect, especially in response to heat stress, according to Y. Malila of Michigan State University and co-authors there and Ohio State University and the University of Minnesota.
In a paper in Poultry Science, they hypothesised that the underlying mechanism responsible for the development of PSE meat arises from differences in expression of several critical genes.
The objective of their study was to determine differential gene expression between normal and PSE turkey meat using a 6K turkey skeletal muscle long oligonucleotide microarray.
Breast meat samples were collected from Randombred Control Line 2 turkeys at 22 weeks of age, and classified as normal or PSE primarily based on marinade uptake (high=normal, low=PSE). Total RNA was isolated from meat samples with the highest (normal, n=6) and the lowest (PSE, n=6) marinade uptake.
Microarray data confirmation was conducted using quantitative real-time PCR. Selection of differentially expressed genes for pathway analysis was performed using a combination of fold change (FC) ranking (FC<−1.66, FC>1.66) and false discovery rate (<0.35) as criteria.
The calcium signalling pathway was highlighted as the top canonical pathway associated with differential gene expression between normal and PSE turkey.
Dramatic down-regulation of fast-twitch myosin heavy chain coupled with up-regulation of slow-twitch myosin and troponin C suggested a switch of skeletal muscle isoforms, which may alter muscle fibre arrangement and formation of actin-myosin complexes.
Changes in expression of genes in the actin cytoskeleton signaling pathway also suggest altered structures of actin filaments that may affect cell motility as well as strength and flexibility of muscle cells.
Substantial down-regulation of pyruvate dehydrogenase kinase, isozyme 4 was observed in PSE samples, suggesting altered regulation of the aerobic metabolic pathway in the birds that developed PSE meat defect.
Malila Y., R.J. Tempelman, K.R.B. Sporer, C.W. Ernst, S.G. Velleman, K.M. Reed and G.M. Strasburg. 2013. Differential gene expression between normal and pale, soft, and exudative turkey meat. Poult. Sci. 92(6):1621-1633. doi: 10.3382/ps.2012-02778
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