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Background Positively correlated with carcass weight and animal growth, the ribeye area (REA) and the backfat thickness (BFT) are economic important carcass traits, which impact directly on producer’s payment. The selection of these traits has not been satisfactory since they are expressed later in the animal’s life and multigene regulated. So, next-generation technologies have been applied in this area to improve animal’s selection and better understand the molecular mechanisms involved in the development of these traits. Correlation network analysis, performed by tools like WGCNA (Weighted Correlation Network Analysis), has been used to explore gene-gene interactions and gene-phenotype correlations. Thus, this study aimed to identify putative candidate genes and metabolic pathways that regulate REA and BFT by constructing a gene co-expression network using WGCNA and RNA sequencing data, to better understand genetic and molecular variations behind these complex traits in Nelore cattle. Results The gene co-expression network analysis, using WGCNA, were built using RNA-sequencing data normalized by transcript per million (TPM) from 43 Nelore steers. Forty-six gene clusters were constructed, between them, three were positively correlated (p-value

Background MicroRNAs (miRNAs) are small noncoding RNAs of approximately 22 nucleotides, highly conserved among species, which modulate gene expression by cleaving messenger RNA target or inhibiting translation. MiRNAs are involved in the regulation of many processes including cell proliferation, differentiation, neurogenesis, angiogenesis, and apoptosis. Beef tenderness is an organoleptic characteristic of great influence in the acceptance of meat by consumers. Previous studies have shown that collagen level, marbling, apoptosis and proteolysis are among the many factors that affect beef tenderness. Considering that miRNAs can modulate gene expression, this study was designed to identify differentially expressed miRNAs that could be modulating biological processes involved with beef tenderness. Results Deep sequence analysis of miRNA libraries from longissimus thoracis muscle allowed the identification of 42 novel and 308 known miRNAs. Among the known miRNAs, seven were specifically expressed in skeletal muscle. Differential expression analysis between animals with high (H) and low (L) estimated breeding values for shear force (EBVSF) revealed bta-mir-182 and bta-mir-183 are up-regulated (q value

Genetic variations in genes involved in lipid storage, which also may interfere with important phenotypic traits such as intramuscular fat deposition in cattle, can represent useful markers in marker assisted selection programs. An important candidate gene is perilipin 2 (PLIN2) that plays a role in the capture of long chain fatty acids and in the formation and stabilization of lipid droplets in different tissues including muscle. As reported by our group, PLIN2 expression level was associated with trans-eQTL (expression quantitative loci distant of gene associated) at chr3: 87, 253, 086 in Nellore cattle, where animals with different genotypes showed different expression level of PLIN2 among the 193 animals and the co-expression analysis detected correlation with intramuscular fat, palmitoleic, oleic and linoleic acids. Then, the objective of this study was to identify and characterize polymorphisms present in the PLIN2 gene of Nellore cattle. To date, there is not much information on mutations in the PLIN2 gene in Bos indicus animals. A total of 134 single nucleotide polymorphisms (SNPs) were identified in the genomic region of PLIN2 gene and five of those are novel with a moderate impact. These SNPs may change the protein effectiveness and, after further association studies and functional validation, could be used as genomic markers in animal breeding program. Made available in DSpace on 2020-01-28T18:11:29Z (GMT). No. of bitstreams: 1 NovelPolymorphismsPLIN2.pdf: 433440 bytes, checksum: 6cc16bdaa51a68669c745c6c5bc70198 (MD5) Previous issue date: 2019 Na publicação: Luciana CA Regitano, Adhemar Zerlotini. gmr16039963.

Background: Integration of high throughput DNA genotyping and RNA-sequencing data allows for the identification of genomic regions that control gene expression, known as expression quantitative trait loci (eQTL), on a whole genome scale. Intramuscular fat (IMF) content and carcass composition play important roles in metabolic and physiological processes in mammals because they influence insulin sensitivity and consequently prevalence of metabolic diseases such as obesity and type 2 diabetes. However, limited information is available on the genetic variants and mechanisms associated with IMF deposition in mammals. Thus, our hypothesis was that eQTL analyses could identify putative regulatory regions and transcription factors (TFs) associated with intramuscular fat (IMF) content traits. Results: We performed an integrative eQTL study in skeletal muscle to identify putative regulatory regions and factors associated with intramuscular fat content traits. Data obtained from skeletal muscle samples of 192 animals was used for association analysis between 461,466 SNPs and the transcription level of 11,808 genes. This yielded 1268 cis- and 10,334 trans-eQTLs, among which we identified nine hotspot regions that each affected the expression of > 119 genes. These putative regulatory regions overlapped with previously identified QTLs for IMF content. Three of the hotspots respectively harbored the transcription factors USF1, EGR4 and RUNX1T1, which are known to play important roles in lipid metabolism. From co-expression network analysis, we further identified modules significantly correlated with IMF content and associated with relevant processes such as fatty acid metabolism, carbohydrate metabolism and lipid metabolism. Conclusion: This study provides novel insights into the link between genotype and IMF content as evident from the expression level. It thereby identifies genomic regions of particular importance and associated regulatory factors. These new findings provide new knowledge about the biological processes associated with genetic variants and mechanisms associated with IMF deposition in mammals. Made available in DSpace on 2018-12-22T23:35:36Z (GMT). No. of bitstreams: 1 APIdentificationCesaretal.pdf: 9576475 bytes, checksum: 54bfa0c637b06996ccf50a3c023171bd (MD5) Previous issue date: 2018-12-20 Article number: 499. Na publicação: Luciana C. A. Regitano, Maurício A. Mudadu, Adhemar Zerlotini.