Polymorphism in the FGFBP1 gene is associated with performance, carcass and meat quality traits in broilers.

Projeto/Plano de Ação: 01.06.10602-03

Quantitative trait loci with sex-specific effects for internal organs weights and hematocrit value in a broiler-layer cross.

Abstract Rapid growth in broilers is associated with susceptibility to metabolic disorders such as pulmonary hypertension syndrome (ascites) and sudden death. This study describes a genome search for QTL associated with relative weight of cardio respiratory and metabolically important organs (heart, lungs, liver and gizzard), and hematocrit value in a Brazilian broiler-layer cross. QTL with similar or different effects across sexes were investigated. At 42 days of age after fasted for 6 h, the F2 chickens were weighed and slaughtered. Weights and percentages of the weight relative to BW42 of gizzard, heart, lungs, liver and hematocrit were used in the QTL search. Parental, F1 and F2 individuals were genotyped with 128 genetic markers (127 microsatellites and 1 SNP) covering 22 linkage groups. QTL mapping analyses were carried out using mixed models. A total of 11 genome-wide significant QTL and five suggestive linkages were mapped. Thus, genomewide significant QTL with similar effects across sexes were mapped to GGA2, 4 and 14 for heart weight, and to GGA2, 8 and 12 for gizzard %. Additionally, five genome-wide significant QTL with different effects across sexes were mapped to GGA 8, 19 and 26 for heart weight; GGA26 for heart % and GGA3 for hematocrit value. Five QTL were detected in chromosomal regions where QTL for similar traits were previously mapped in other F2 chicken populations. Seven novel genome-wide significant QTL are reported here, and 21 positional candidate genes in QTL regions were identified

Integration of GWAS, CNV and sele ction signature reveals candidate genes for abdominal fat regulation in chickens.

Abstract: Carcass fat content is an economically important trait in commercial chickens. The use of genome-wide high density SNPs may improve the power and resolution to identify QTLs, putative candidate genes and copy number variations (CNVs), for selection programs. The main goal of this study was to identify genomic windows and putative candidate genes for carcass fat content. We checked the overlap of QTL with regions demonstrating signatures of selection and inherited CNVs identified in the same population. A total of 497 42 day-old chickens from the EMBRAPA F2 Chicken Resource Population developed for QTL studies were genotyped with the 600K SNP genotyping array (Affymetrix®), and phenotyped for carcass fat content weight (CFCW) and carcass fat content on a dry matter basis (CFCDM). After quality control, a total of 480 samples and 371,557 SNPs annotated in autosomal chromosomes (GGA1-28) based on Gallus_gallus-5.0 (NCBI) were kept for further analysis. GWAS analyses were performed with GenSel software using BayesB method (π=0.9988) to identify genomic windows associated with CFCW or CFC%. We identified 15 genomic windows associated with CFC% on GGA1, 7, 15, 20 and 28, and from those, we identified two adjacent windows on GGA7 considered as the same QTL explaining 1.31 and 2.18% of the genetic variance for CFCW and CFC%, respectively. This QTL overlapped with one regions previsiouly know to regulate abdominal fat in chickens and the QTL region encompassed two putative candidate genes overlapping with signatures of selection and inherited CNVs. Our findings are helpful to better understand the genetic regulation of fatness in chickens. Resumo: O teor de gordura na carcaça é uma característica economicamente importante em frangos comerciais. O uso de SNPs de alta densidade em todo o genoma pode melhorar o poder e a resolução para identificar QTLs, genes candidatos putativos e variações no número de cópias (CNVs), para programas de seleção. O principal objetivo deste estudo foi identificar janelas genômicas e possíveis genes candidatos para o conteúdo de gordura na carcaça. Verificamos a sobreposição de QTL com regiões demonstrando assinaturas de seleção e CNVs herdadas identificadas na mesma população. Um total de 497 galinhas com 42 dias de idade da EMBRAPA F2 Chicken Resource Population desenvolvidas para estudos QTL foram genotipadas com o arranjo de genótipos SNP 600K (Affymetrix®) e fenotipadas para peso de gordura na carcaça (CFCW) e teor de gordura na carcaça seca. matéria básica (CFCDM). Após o controle de qualidade, um total de 480 amostras e 371.557 SNPs anotados em cromossomos autossômicos (GGA1-28) baseados em Gallus_gallus-5.0 (NCBI) foram mantidos para análise posterior. As análises de GWAS foram realizadas com o software GenSel usando o método de BayesB (π = 0,9988) para identificar janelas genômicas associadas ao CFCW ou CFC%. Foram identificadas 15 janelas genômicas associadas a% CFC em GGA1, 7, 15, 20 e 28 e, a partir delas, identificamos duas janelas adjacentes em GGA7 consideradas como os mesmos QTLs explicando 1,31 e 2,18% da variância genética para CFCW e CFC% , respectivamente. Este QTL se sobrepunha a uma das regiões previsamente conhecidas para regular a gordura abdominal em frangos e a região QTL englobava dois supostos genes candidatos que se sobrepunham com assinaturas de seleção e CNVs herdadas. Nossas descobertas são úteis para entender melhor a regulação genética da gordura em frangos