AUTHOR=Verardo Lucas Lima , e Silva Fabyano Fonseca , Machado Marco Antonio , do Carmo Panetto João Cláudio , de Lima Reis Faza Daniele Ribeiro , Otto Pamela Itajara , de Almeida Regitano Luciana Correia , da Silva Luiz Otávio Campos , do Egito Andréa Alves , do Socorro Maués Albuquerque Maria , Zanella Ricardo , da Silva Marcos Vinicius Gualberto Barbosa 

TITLE=Genome-Wide Analyses Reveal the Genetic Architecture and Candidate Genes of Indicine, Taurine, Synthetic Crossbreds, and Locally Adapted Cattle in Brazil

JOURNAL=Frontiers in Genetics

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.702822

DOI=10.3389/fgene.2021.702822

ISSN=1664-8021

ABSTRACT=<p>Cattle population history, breeding systems, and geographic subdivision may be reflected in runs of homozygosity (ROH), effective population size (<italic>N</italic><sub>e</sub>), and linkage disequilibrium (LD) patterns. Thus, the assessment of this information has become essential to the implementation of genomic selection on purebred and crossbred cattle breeding programs. In this way, we assessed the genotype of 19 cattle breeds raised in Brazil belonging to taurine, indicine, synthetic crossbreds, and Iberian-derived locally adapted ancestries to evaluate the overall LD decay patterns, <italic>N</italic><sub>e</sub>, ROH, and breed composition. We were able to obtain a general overview of the genomic architecture of cattle breeds currently raised in Brazil and other tropical countries. We found that, among the evaluated breeds, different marker densities should be used to improve the genomic prediction accuracy and power of genome-wide association studies. Breeds showing low <italic>N</italic><sub>e</sub> values indicate a recent inbreeding, also reflected by the occurrence of longer ROH, which demand special attention in the matting schemes to avoid extensive inbreeding. Candidate genes (e.g., <italic>ABCA7</italic>, <italic>PENK</italic>, <italic>SPP1</italic>, <italic>IFNAR1</italic>, <italic>IFNAR2</italic>, <italic>SPEF2</italic>, <italic>PRLR</italic>, <italic>LRRTM1</italic>, and <italic>LRRTM4</italic>) located in the identified ROH islands were evaluated, highlighting biological processes involved with milk production, behavior, rusticity, and fertility. Furthermore, we were successful in obtaining the breed composition regarding the taurine and indicine composition using single-nucleotide polymorphism (SNP) data. Our results were able to observe in detail the genomic backgrounds that are present in each breed and allowed to better understand the various contributions of ancestor breeds to the modern breed composition to the Brazilian cattle.</p>