| Autor: |
Reis HBD; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil., Carvalho ME; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil., Espigolan R; Department of Animal Science and Biological Sciences, Federal University of Santa Maria (UFSM), Av. Independencia, 3751, Palmeira das Missões 98300-000, RS, Brazil., Poleti MD; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil., Ambrizi DR; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil., Berton MP; School of Agricultural and Veterinary Studies (FCAV), São Paulo State University, Jaboticabal 14884-900, SP, Brazil., Ferraz JBS; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil., de Mattos Oliveira EC; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil., Eler JP; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, SP, Brazil. |
| Abstrakt: |
The meat market has enormous importance for the world economy, and the quality of the product offered to the consumer is fundamental for the success of the sector. In this study, we analyzed a database which contained information on 2470 animals from a commercial farm in the state of São Paulo, Brazil. Of this total, 2181 animals were genotyped, using 777,962 single-nucleotide polymorphisms (SNPs). After quality control analysis, 468,321 SNPs provided information on the number of genotyped animals. Genome-wide association analyses (GWAS) were performed for the characteristics of the rib eye area (REA), subcutaneous fat thickness (SFT), shear force at 7 days' ageing (SF7), and intramuscular fat (IMF), with the aid of the single-step genomic best linear unbiased prediction (ssGBLUP) method, with the purpose of identifying possible genomic windows (~1 Mb) responsible for explaining at least 0.5% of the genetic variance of the traits under analysis (≥0.5%). These genomic regions were used in a gene search and enrichment analyses using MeSH terms. The distributed heritability coefficients were 0.14, 0.20, 0.18, and 0.21 for REA, SFT, SF7, and IMF, respectively. The GWAS results indicated significant genomic windows for the traits of interest in a total of 17 chromosomes. Enrichment analyses showed the following significant terms (FDR ≤ 0.05) associated with the characteristics under study: for the REA, heat stress disorders and life cycle stages; for SFT, insulin and nonesterified fatty acids; for SF7, apoptosis and heat shock proteins (HSP27); and for IMF, metalloproteinase 2. In addition, KEGG (Kyoto encyclopedia of genes and genomes) enrichment analysis allowed us to highlight important metabolic pathways related to the studied phenotypes, such as the growth hormone synthesis, insulin-signaling, fatty acid metabolism, and ABC transporter pathways. The results obtained provide a better understanding of the molecular processes involved in the expression of the studied characteristics and may contribute to the design of selection strategies and future studies aimed at improving the productivity of Nellore cattle. |
