Novel SNP of EPAS1 gene associated with higher hemoglobin concentration revealed the hypoxia adaptation of yak(Bos grunniens)

Endothelial PAS domain protein 1 gene （EPAS1） is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hematologic parameters in yak, we firstly quantified the tissue expression patterns for EPASl mRNA of yak, identified polymorphism in this gene and evaluated its association with hematologic parameters. Expression of EPAS1 mRNA was detected in all eight tissues （heart, liver, lung, spleen, pancreas, kidney, muscles and ovary）. The expressions of EPAS1 in lung and pancreas were extremely higher than other tissues examined. Three novel single nucleotide polymorphisms （SNPs） （g.83052 C〉T, g.83065 G〉A and g.83067 C〉A） within the EPAS1 were identified and genotyped in Pali （PL）, Gannan （GN） and Tianzhu White （TZW） yak breeds. Significant higher frequencies of the AA and GA genotypes and A allele of the g.83065 G〉A were observed in the PL and GN breeds than that in the TZW breed （P〈0.01）. Association analysis of the PL breed indicated that the g.83065 G〉A polymorphism was significantly associated with hemoglobin （HGB） concentration in yaks （P〈0.05）. Individuals with genotype AA had significantly higher HGB concentration （P〈0.05） than those with genotype GA and GG. All these results will help our further understanding of biological functional of yak EPAS1 gene in responding to hypoxia and also indicate EPAS1 might contribute to the hypoxia adaptation of the yak.

Association of H-FABP gene polymorphisms with intramuscular fat content in Threeyellow chickens and Hetian-black chickens

Background： To explore the relationship between the heart-type fatty acid binding protein（H-FABP） gene and intramuscular fat（IMF）, a polymorphism of the second exon of the H-FABP gene was investigated in 60 Three-yellow chickens（TYCs） and 60 Hetian-black chickens（HTBCs）.Results： The IMF contents of the cardiac, chest and leg muscles in HTBC were increased compared with TYC. Both TYC and HTBC populations exhibited Hardy-Weinberg Equilibrium（HWE） according to the χ2test. Three variations of the two birds were detected, namely, G939 A, G982 A and C1014 T. HTBCs with the TT genotypes exhibit increased IMF content in the chest muscles compared with the TC genotype. Thus, the G982 A site could be considered a genetic marker for selecting increased IMF content in the chest muscles of HTBC. The correlation coefficients revealed that H-FABP m RNA expression was negatively correlated with the IMF content in the cardiac, chest and leg muscles of HTBC and in the cardiac and chest muscles of TYC. The relative m RNA expression of H-FABP was reduced in the cardiac and leg muscles of HTBC compared with TYC, but this difference was not observed at the protein level, as assessed by Western blot analysis.Conclusions： These findings offer essential data that can be useful in the breeding program of HTBC and future research exploring the role of H-FABP in IMF deposition and regulation in chickens.

Transcriptional response of porcine skeletal muscle to feeding a linseed-enriched diet to growing pigs

Background： To investigate the effect of feeding a linseed-enriched diet to growing-finishing pigs on gene expression in skeletal muscle, pigs were fed with a linseed-enriched diet for 0, 30, 60 and 90 d. Transcriptional profiles of longissimus dorsi muscle were measured using Affymetrix Genechip.Results： Results showed that 264 genes were identified as differentially expressed genes（DEGs）. The strongest transcriptional response was clearly observed at 30 d. DEGs were assigned to several main functional terms,including transcription, apoptosis, intracellular receptor-mediated signaling, muscle organ development, fatty acid metabolic process, cell motion, regulation of glucose metabolic process, spermatogenesis and regulation of myeloid cell differentiation. We also found that transcriptional changs of several transcription cofactors might contribute to n-3 PUFAs regulated gene expression. In addition, the increased expression of IGF-1, insulin signaling pathway and the metabolism of amino acids might involve in the muscle growth induced by feeding a linseedenriched diet. The results also provide the new evidence that the expression changes of PTPN1, HK2 and PGC-1αmight contribute to the regulation of insulin sensitivity by n-3 PUFAs.Conclusions： Our finding provided correlative evidence that feeding the linseed enriched diet affact expression of genes involved in insulin signaling pathway and the metabolism of amino acids.