Polymorphism of the PLIN1 gene and its association with body measures and ultrasound carcass traits in Qinchuan beef cattle

The PLIN1 gene produces a phosphorylated protein wrapped in lipid droplets in adipocytes. This phosphorylation assists the mobilization of fat into adipose tissue. The purpose of the experiment was to study the polymorphism of the PLIN1 gene and its relationship with the body and carcass characteristics of Qinchuan cattle to find molecular genetic markers that can be used for breeding. The expression level of the PLIN1 gene was determined in various tissues by qRT-PCR. The results showed that the highest level of PLN1 expression was found in subcutaneous fat, followed by the heart and longissimus muscle, and the lowest level was found in the kidney. Five SNP loci of the PLIN1 gene were identified in 510 Qinchuan cattle, including g.3580T>C (SNP1), g.3898G>A (SNP2), g.8333G>A (SNP3), g.10517T>C (SNP4), and g.10538G>T (SNP5). The results show that SNP1, SNP2, SNP3, and SNP4 were moderately polymorphic (0.25 < PIC < 0.5), while SNP5 was minimally polymorphic (PIC < 0.25). SNP2, SNP3, and SNP5 were within Hardy-Weinberg equilibrium (P > 0.05), but SNP1 and SNP4 were not (P < 0.05). Correlation analysis showed that the five SNPs of the PLIN1 gene were correlated with back-fat depth, intramuscular fat, and chest depth of Qinchuan cattle. The double haplotype H2H4 in Qinchuan beef was associated with body and carcass traits. We conclude that variants mapped within PLIN1 can be used in marker-assisted selection for carcass quality and body traits in breed improvement programs for Qinchuan cattle. Key words: PLN1 gene, mRNA expression, single nucleotide polymorphisms, body measurement traits, marker-assisted selection, Qinchuan cattle. Le gene PLIN1 produit une proteine phosphorylee enrobee de gouttelettes lipidiques dans les adipocytes. Cette phosphorylation aide a mobiliser le gras dans les tissus adipeux. Le but de cette experience etait d'etudier le polymorphisme au sein du gene PLIN1 et sa relation avec les caracteres de la morphologie corporelle et de la carcasse des bovins de race Qinchuan en vue de trouver des marqueurs moleculaires pouvant servir en selection. Le niveau d'expression du gene PLIN1 a ete determine chez differents tissus par qRT-PCR. Les resultats ont montre que le plus haut niveau d'expression est rencontre dans le gras sous-cutane, suivi du cour et du muscle longissimus, tandis que le plus faible niveau etait observe dans les reins. Cinq SNP dans le gene PLIN1 ont ete identifies au sein de 510 bovins Qinchuan, dont g.3580T>C (SNP1), g.3898G>A (SNP2), g.8333G>A (SNP3), g.10517T>C (SNP4) et g.10538G>T (SNP5). Les resultats montrent que les SNP1, SNP2, SNP3 et SNP4 etaient moderement polymorphes (0,25 < PIC < 0,5), tandis que le SNP5 etait peu polymorphe (PIC < 0,25). Les SNP2, SNP3 et SNP5 etaient en equilibre Hardy-Weinberg (P > 0,05), tandis que les SNP1 et SNP4 ne l'etaient pas (P < 0,05). Une analyse de correlation a montre que les cinq SNP du gene PLIN1 etaient correles avec l'epaisseur de gras dorsal, le gras intramusculaire, et la profondeur du thorax chez les bovins Qinchuan. Le double haplotype H2H4 chez la race Qinchuan etait associe a la morphologie et a des caracteres de la carcasse. Les auteurs concluent que les variants situes dans le gene PLIN1 peuvent servir a selectionner des caracteres de la qualite de la carcasse et de la morphologie dans les programmes d'amelioration genetique des bovins Qinchuan. [Traduit par la Redaction] Mots-cles : gene PLIN1, expression de l'ARNm, polymorphismes mononucleotidiques, caracteres de la morphologie corporelle, selection assistee par marqueurs, bovins Qinchuan.
Introduction In the mammalian body, the main adipose depots are subcutaneous, visceral, intramuscular, and intermuscular fat. Intramuscular fat is a key factor that defines meat quality in meat-producing animals (Cai [...]