Association of hormone-sensitive lipase (HSL) gene polymorphisms with the intramuscular fat content in two Chinese beef cattle breeds

Effects of Acorns on Fatty Acid Composition and Lipid Metabolism in Adipose Tissue of Yuxi Black Pigs

The objective of the present research was the examination of how varying proportions of an acorn diet affects the deposition of subcutaneous fat and the composition of fatty acids (FAs) in Yuxi black pigs. Ninety pigs (with a balanced sex ratio and a similar weight 99.60 ± 2.32 kg) were stochastically assigned to the control group (CON) and the dietary acorn experimental groups (AEG). The CON was fed basal diets and the AEG1, AEG2, AEG3, and AEG4 groups were provided with dietary regimens comprising twenty, thirty, forty, and fifty per cent acorns, respectively. Each group consisted of six pigs, with three replicates. The breeding cycle was four months. The results demonstrated that, in comparison with the CON group, the lean meat rate was significantly increased in all test groups (p < 0.05), while in backfat thickness, loin eye area, carcass weight and slaughter rate was no significant difference (p > 0.05). The serum TC/HDL (total cholesterol divided by high-density lipoprotein-cholesterol) and TG/HDL (Triglyceride divided by high-density lipoprotein-cholesterol) levels in the AEG1 and AEG2 groups were significantly lower than the CON group (p < 0.05). There was no significant effect on the composition of FAs (p > 0.05). The number of fat cells in subcutaneous back fat and subcutaneous abdominal fat was significantly increased, and the area of fat cells was decreased (p < 0.05). Furthermore, the levels of ATGL and HSL expression in the subcutaneous back fat, as well as ACC, FAS, ATGL, PPARγ, and HSL expression in the subcutaneous abdominal fat, were significantly increased in the AEG2 group compared to the CON group (p < 0.05). Additionally, the expression of ACC, FAS, FABP4, PPARγ, C/EBPα, and FAS/HSL in the subcutaneous back fat, as well as FABP4, C/EBPα, and FAS/HSL in the subcutaneous abdominal fat, were significantly lower in the AEG2 group compared to the CON group (p < 0.05). In conclusion, it has been found that a 30% acorn diet can inhibit subcutaneous fat deposition and enhance the nutritional value of pork and the health of Yuxi black pigs.

Variation in the HSL Gene and Its Association with Carcass and Meat Quality Traits in Yak

Hormone-sensitive lipase (HSL) is involved in the breakdown of triacylglycerols in adipose tissue, which influences muscle tenderness and juiciness by affecting the intramuscular fat content (IMF). This study analyzed the association between different genotypes and haplotypes of the yak HSL gene and carcass and meat quality traits. We used hybridization pool sequencing to detect exon 2, exon 8, and intron 3 variants of the yak HSL gene and genotyped 525 Gannan yaks via KASP to analyze the effects of the HSL gene variants on the carcass and meat quality traits in yaks. According to the results, the HSL gene is highly expressed in yak adipose tissue. Three single nucleotide polymorphisms (SNPs) were identified, with 2 of them located in the coding region and one in the intron region. Variants in the 2 coding regions resulted in amino acid changes. The population had 3 genotypes of GG, AG, and AA, and individuals with the AA genotype had lower WBSF values (p < 0.05). The H3H3 haplotype combinations could improve meat tenderness by reducing the WBSF values and the cooking loss rate (CLR) (p < 0.05). H1H1 haplotype combinations were associated with the increased drip loss rate (DLR) (p < 0.05). The presence of the H1 haplotype was associated the increased CLR in yaks, while that of the H2 haplotype was associated with the decreased DLR in yaks (p < 0.05). These results demonstrated that the HSL gene may influence the meat quality traits in yaks by affecting the IMF content in muscle tissues. Consequently, the HSL gene can possibly be used as a biomarker for improving the meat quality traits in yaks in the future.

Detection of two SNPs of the LIPE gene in Holstein-Friesian cows with divergent milk production

The LIPE gene (lipase E, hormone-sensitive type), also known as hormone-sensitive lipase, acts as a primary regulator of lipid metabolism during lactation in cows. We studied a total of two hundred Holstein-Friesian cows and performed sequencing analysis that revealed two synonymous nucleotide changes within the LIPE gene: a transition change, c.276 T > C in exon 2 (g.50631651 T > C; position 351 of GenBank: ON638900) and a transversion change, c.219C > A in exon 6 (g.50635369C > A; position 1070 of GenBank: ON638901). The observed genotypes were TC and CC for the c.276 T > C SNP and CC and CA for the c.219C > A SNP. Notably, the heterozygous TC genotype of the T351C SNP exhibited a significant association with high milk yield. Furthermore, the T351C SNP displayed significant associations with various milk parameters, including temperature, freezing point, density and the percentages of fat, protein, lactose, solids and solids-not-fat, with the homozygous CC genotype showing higher values. The c.219C > A SNP also demonstrated a significant association with milk composition, with heterozygous genotypes (CA) exhibiting higher percentages of fat, protein, and lactose compared to homozygous genotypes (CC). This effect was consistent among both high and low milk producers for fat and lactose percentages, while high milk producers exhibited a higher protein percentage than low milk producers. These findings highlight the importance of considering the detected SNPs in marker-assisted selection and breeding programs for the identification of high milk-producing Holstein-Friesian cows and potentially other breeds. Moreover, this study strongly supports the fundamental role of the LIPE gene in milk production and composition in lactating animals.

Effects of the CDC10 (Septin 7) Gene on the Proliferation and Differentiation of Bovine Intramuscular Preadipocyte and 3T3-L1 Cells

Intramuscular fat content and marbling affecting meat quality are important economic traits in beef cattle. CDC10 (cell division cycle 10 or Septin 7), a member of the septin family involved in cellular proliferation, was considered as a functional and positional candidate gene for beef marbling. In a previous study, we revealed that the expression levels of CDC10 were also positively correlated with marbling scores in Japanese Black cattle. However, the regulatory mechanism of the CDC10 gene on IMF deposition in cattle remains unclear. In the present study, flow cytometry, EdU proliferation assays, and Oil Red O staining results showed that overexpression of CDC10 could promote the differentiation of bovine intramuscular preadipocyte (BIMP) and 3T3-L1 cells, whereas knockdown of CDC10 resulted in the opposite consequences. Furthermore, quantitative PCR and Western blotting results showed that overexpression of CDC10 could promote the expression levels of adipogenic marker genes PPARγ and C/EBPα at both mRNA and protein levels in BIMP and 3T3-L1 cells, whereas knockdown of CDC10 resulted in the opposite consequences. Our results provide new insights into the regulatory roles of CDC10 in adipocytes in animals.

Towards Sustainable Sources of Omega-3 Long-Chain Polyunsaturated Fatty Acids in Northern Australian Tropical Crossbred Beef Steers through Single Nucleotide Polymorphisms in Lipogenic Genes for Meat Eating Quality

This study aimed to identify single nucleotide polymorphisms (SNP) in lipogenic genes of northern Australian tropically adapted crossbred beef cattle and to evaluate associations with healthy lipid traits of the Longissimus dorsi (loin eye) muscle. The hypothesis tested was that there are significant associations between SNP loci encoding for the fatty acid binding protein 4 (FABP4), stearoyl-CoA desaturase (SCD) and fatty acid synthase (FASN) genes and human health beneficial omega-3 long-chain polyunsaturated fatty acids (ω3 LC-PUFA) within the loin eye muscle of northern Australian crossbred beef cattle. Brahman, Charbray, and Droughtmaster crossbred steers were fed on Rhodes grass hay augmented with desmanthus, lucerne, or both, for 140 days and the loin eye muscle sampled for intramuscular fat (IMF), fat melting point (FMP), and fatty acid composition. Polymorphisms in FABP4, SCD, and FASN genes with significant effects on lipid traits were identified with next-generation sequencing. The GG genotype at the FABP4 g.44677239C>G locus was associated with higher proportion of linoleic acid than the CC and CG genotypes (p < 0.05). Multiple comparisons of genotypes at the SCD g.21266629G>T locus indicated that the TT genotype had significantly higher eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids than GG genotype (p < 0.05). Significant correlations (p < 0.05) between FASN SNP and IMF, saturated and monounsaturated fatty acids were observed. These results provide insights into the contribution of lipogenic genes to intramuscular fat deposition and SNP marker-assisted selection for improvement of meat-eating quality, with emphasis on alternate and sustainable sources of ω3 LC-PUFA, in northern Australian tropical crossbred beef cattle, hence an acceptance of the tested hypothesis.

Integrated analysis of expression profiles with meat quality traits in cattle

MicroRNAs (miRNAs) play a vital role in improving meat quality by binding to messenger RNAs (mRNAs). We performed an integrated analysis of miRNA and mRNA expression profiling between bulls and steers based on the differences in meat quality traits. Fat and fatty acids are the major phenotypic indices of meat quality traits to estimate between-group variance. In the present study, 90 differentially expressed mRNAs (DEGs) and 18 differentially expressed miRNAs (DEMs) were identified. Eighty-three potential DEG targets and 18 DEMs were used to structure a negative interaction network, and 75 matching target genes were shown in this network. Twenty-six target genes were designated as intersection genes, screened from 18 DEMs, and overlapped with the DEGs. Seventeen of these genes enriched to 19 terms involved in lipid metabolism. Subsequently, 13 DEGs and nine DEMs were validated using quantitative real-time PCR, and seven critical genes were selected to explore the influence of fat and fatty acids through hub genes and predict functional association. A dual-luciferase reporter and Western blot assays confirmed a predicted miRNA target (bta-miR-409a and PLIN5). These findings provide substantial evidence for molecular genetic controls and interaction among genes in cattle.