A genome-wide association study for morphometric traits in quarter horse

A genome-wide association study for morphometric traits was conducted in 184 Quarter Horses, 120 from a racing population, and 64 from a cutting population, which were genotyped using the Illumina EquineSNP50 chip. Association analysis was performed with 42,058 single-nucleotide polymorphisms (SNPs) (after quality control) using Qxpak5 software. The following traits were measured: weight (W), rump length (RL), and body length (BL). These morphometric traits are important for the best performance in race and cutting events. For weight, three SNPs associated (P < .0001) were found on chromosomes (Equus caballus autosomes [ECA]) 2 and 3. For rump length, eight SNPs associated (P < .0001) were found on ECA 2, 3, 6, 7, 9, 21, and 26. On ECA 3 and ECA 8, two SNPs were associated (P < .0001) with body length. So, a total of 13 important chromosomal regions were identified with Q values of 0.53 (SNPs for W), 0.40 (SNPs for RL), and 0.99 (SNPs for BL). Positional and functional candidate genes emerging from this study were WWOX and AAVPR1A. Further studies are required to confirm these associations in other populations. (c) 2014 Elsevier Inc. All rights reserved

Effects of polymorphic microsatellites in the regulatory region of IGF1 and GHR on growth and carcass traits in beef cattle

Growth hormone (GH), insulin-like growth factors 1 and 2 (IGF1 and IGF2) and their associated binding proteins and transmembrane receptors (GHR, IGF1R and IGF2R) play an important role in the physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of microsatellite markers located in the 5'-regulatory region of the IGF1 and GHR genes in beef cattle belonging to different genetic groups and to determine effects of these markers on growth and carcass traits in these animals under an intensive production system. For this purpose, genotyping was performed on 384 bulls including 79 Nellore, 30 Canchim (5/8 Charolais + 3/8 Zebu) and 275 crossbred animals originating from crosses of Simmental (1/2 Simmental, n = 30) and Angus (1/2 Angus, n = 245) sires with Nellore females. The effects of substituting L allele for S allele of GHR microsatellite across Nellore, Canchim and 1/2 Angus were significant for weight gain and body weight (P < 0.05). The IGF1 microsatellite allele substitutions of 229 for 225 within Nellore group and of 225 for 229 within 1/2 Angus were not significant for any of the traits

Genetic parameters for earnings in Quarter Horse

In this study, we estimated the heritability (h(2)) of earnings in the Quarter Horse in order to evaluate the inclusion of this trait in breeding programs. Records from 14,754 races of 2443 horses from 1978-2009 were provided by Sorocaba Hippodrome, Sao Paulo, Brazil. All ancestors of the registered horses were included in the pedigree file until the 4th generation. Log-transformed performance measures (LPM) were analyzed for animals aged 2, 3, and 4 years and during their entire career. The h(2) estimates were obtained using a multi-trait model and Gibbs sampling that included the effects of sex, year of race, and animal in all analyses. Five analyses were performed: 1 in which LPM was divided by the number of prizes, 1 in which LPM was divided by the number of race starts, and 3 analyses that included the number of prizes, number of race starts, and both (LPM_cNPS) as covariates. Analysis was performed with and without inclusion of the maternal effect. Models were compared based on the deviance information criterion and LPM_cNPS including maternal effects was found to be the best model. The h(2) estimates and standard deviation obtained using model LPM_cNPS were 0.19 +/- 0.08, 0.21 +/- 0.08, 0.22 +/- 0.09, and 0.21 +/- 0.07 for earnings at 2, 3, and 4 years of age and total career, respectively. Our analyses indicate that earnings are subject to selection and can be included in breeding programs to improve the racing performance of Quarter Horses

Alternative genotyping method for the single nucleotide polymorphism A2959G (AF159246) of the bovine CAST gene

O objetivo deste trabalho foi genotipar o polimorfismo de nucleotídeo único (single nucleotide polymorphism - SNP) A2959G (AF159246) do gene CAST bovino, pela técnica de PCR-RFLP, e reportar a sua utilização pela primeira vez. Para tanto, 147 animais Bos indicus e Bos taurus x Bos indicus foram genotipados. A acurácia do método foi confirmada por meio do seqüenciamento direto de produtos de PCR de nove indivíduos. A menor freqüência do alelo A, favorável à maciez da carne, foi confirmada nos animais Bos indicus. O uso da PCR-RFLP, para a genotipagem do SNP do gene CAST bovino, mostrou-se consistente e de baixo custo, o que permite a sua análise por laboratórios dotados de estrutura básica.The objective of this work was to genotype the single nucleotide polymorphism (SNP) A2959G (AF159246) of bovine CAST gene by PCR-RFLP technique, and to report its use for the first time. For this, 147 Bos indicus and Bos taurus x Bos indicus animals were genotyped. The accuracy of the method was confirmed through the direct sequencing of PCR products of nine individuals. The lowest frequency of the meat tenderness favorable allele (A) in Bos indicus was confirmed. The use of PCR-RFLP for the genotyping of the bovine CAST gene SNP was shown to be robust and inexpensive, which will greatly facilitate its analysis by laboratories with basic structure.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Association between IGF-I, IGF-IR and GHRH gene polymorphisms and growth and carcass traits in beef cattle

Molecular biology techniques are of help in genetic improvement since they permit the identification, mapping and analysis of polymorphisms of genes encoding proteins that act on metabolic pathways involved in economically interesting traits. The somatotrophic axis, which essentially consists of growth hormone releasing hormone (GHRH), growth hormone (GH), insulin-like growth factors I and II (IGF-I and IGF-II), and their associated binding proteins and receptors (GHRHR, GHR, IGF-IR and IGF-IIR), plays a key role in the metabolism and physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of the IGF-I/SnaBI, IGF-IR/TaqI and GHRH/HaeIII gene polymorphisms in different genetic groups of beef cattle and to determine associations between these polymorphisms and growth and carcass traits. For this purpose, genotyping was performed on 79 Nellore animals, 30 Canchim (5/8 Charolais+3/8 Zebu) animals and 275 crossbred cattle originating from the crosses of Simmental (n=30) and Angus (n=245) sires with Nellore females. In the association studies, traits of interest were analyzed using the GLM procedure of SAS and least square means of the genotypes were compared by the Tukey test. Associations of IGF-I/SnaBI genotypes with body weight and subcutaneous backfat were significant (p 0.05). The IGF-IR/TaqI and GHRH/HaeIII polymorphisms showed no association with production traits. (c) 2004 Elsevier B.V All rights reserved

Effects of CSN3 and LGB gene polymorphisms on production traits in beef cattle

The objective of the present study was to estimate the allele and genotype frequencies of the CSN3/Hinfl and LGB/HaeIII gene polymorphisms in beef cattle belonging to different genetic groups, and to determine the effects of these polymorphisms on growth and carcass traits in these animals, which are submitted to an intensive production model. Genotyping was performed on 79 Nelore, 30 Canchim (5/8 Charolais + 3/8 Zebu) and 275 crossbred cattle originating from the crosses of Simmental (n = 30) and Angus (n = 245) sires with Nelore females. Body weight, weight gain, dressing percentage, longissimus dorsi area and backfat thickness were fitted using the GLM procedure, and least square means of the genotypes were compared by the F test. The results showed that the CSN3/Hinfl and LGB/HaeIII polymorphisms did not have any effect on growth or carcass traits (p > 0.05). Copyright by the Brazilian Society of genetics

Characterization and transcriptional analysis of the promoter region of the Duffy blood group, chemokine receptor (DARC) gene in cattle

The Duffy antigen is the only receptor for Plasmodium vivax, a hemoparasite of the phylum Apicomplexa and the cause of vivax malaria in humans. Resistance to this parasite in the majority of black African individuals and their descendents is due to a mutation in the gene promoter region, which blocks its transcription on erythrocytes. Regarding bovine babesiosis, it is known that taurine breeds are more susceptible to parasite infection than zebuine breeds. In order to verify whether the same human resistance occurs in bovine, the 5' flanking region of the DARC gene was isolated and characterized in Bos indicus and Bos taurus. Four single nucleotide polymorphisms were identified and genotyped (SNP1: EF_647729.1:g.91 C > T; SNP2: EF_647729.1:g.405C > T; SNP3: EF_647729.1: g.433A > G and SNP4: EF_647729.1:g.588A > G), which showed significant frequency differences among 99 bovines of each species (n = 198). Characterization of the isolated region revealed the presence of 6 putative haplotypes, 14 genotypes, which are formed by haplotypes, and numerous putative transcription factor binding sites. Only the thymine presence on SNPs 1 and 2, more common in B. indicus, was observed to alter some of the sites in this region. Despite this fact, analyses through real-time PCR on bovines that present the most common homozygote genotypes of each species, which contrast for all the polymorphism, revealed no difference on the DARC gene transcription. Thus, in principle, it was concluded that the polymorphisms identified would not be useful as molecular markers in an improvement program for resistance to babesiosis. (C) 2009 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Caracterização da variabilidade de genes relacionados à fertilidade de machos e ao temperamento em eqüinos da raça brasileira Mangalarga

The aims of the present study were to propose a PCR-RFLP genotyping method for the AJ_315378:c.110A>G and AB_264325:c. 771G>C SNPs in the equine CRISP1 and HTR1A genes, respectively, as well as to characterize these and another polymorphism, AB_098561:c.1470G>A of the SLC6A4 gene, in order to provide a basis for future studies investigating the association between DNA markers and traits of interest in this breed. For this, 151 Mangalarga horses of both sexes, representatives of the population of the Sate of São Paulo, Brazil, were used. PCR-RFLP was found to be adequate for the genotyping of the SNPs AJ_315378: c.110A>G of the CRISP1 and AB_264325:c.771G>C of the HTR1A. However, the polymorphism of the CRISP1 probably does not occur in Mangalarga horses, a fact impairing association studies of this marker with traits related to male fertility. The estimative of the population genetic parameters obtained for the polymorphisms AB_264325:c.771G>C of the HTR1A and AB_098561:c.1470G> A of the SLC6A4 in the studied sample discourage the conduct of research addressed the association between markers and traits related to temperament

Identification and characterization of polymorphisms within the 5' flanking region, first exon and part of first intron of bovine GH gene

The aim of the present study was to identify and characterize polymorphisms within the 5' flanking region, first exon and part of first intron of the bovine growth hormone gene among different beef cattle breeds: Nelore (n = 25), Simmental (n = 39), Simbrasil (n = 24), Simmental x Nelore (n = 30), Canchim x Nelore (n = 30) and Angus x Nelore (n = 30). Two DNA fragments (GH1, 464 bp and GH2, 453 bp) were amplified by polymerase chain reaction and then used for polymorphism identification by SSCP. Within the GH1 fragment, five polymorphisms were identified, corresponding to three different alleles: GH1.1, GH1.2 and GH1.3 (GenBank: AY662648, AY662649 and AY662650, respectively). These allele sequences were aligned and compared with bovine GH gene nucleotide sequence (GenBank: M57764 and AF118837), resulting in the identification of five insertion/deletions (INDELs) and five single nucleotide polymorphisms (SNPs). In the GH2 fragment two alleles were identified, GH2.1 and GH2.2 (GenBank: AY662651 and AY662652, respectively). The allele sequences were compared with GenBank sequences (M57764, AF007750 and AH009106) and three INDELs and four SNPs were identified. In conclusion, we were able to identify six new polymorphisms of the bovine GH gene (one INDEL and five SNPs), which can be used as molecular markers in genetic studies

Detection and quantification of Duffy antigen on bovine red blood cell membranes using a polyclonal antibody

As doenças infecciosas e parasitárias causam perdas importantes em vários setores da produção da pecuária mundial. Estima-se que mais de 600 milhões de bovinos de países tropicais e subtropicais estejam expostos à infecção por Babesia sp. gerando grande prejuízo econômico. Os gêneros Babesia e Plasmodium são hemoparasitas pertencentes ao filo Apicomplexa e apresentam características comuns no processo de invasão eritrocitária. A babesiose bovina causada por Babesia bigemina e Babesia bovis apresenta sinais clínicos similares a malária humana causada por Plasmodium vivax e Plasmodium falciparum. A glicoproteína Duffy é a única receptora para o P. vivax em humanos. A maioria dos indivíduos negros africanos é resistente a este parasita devido a uma mutação que provoca a ausência de expressão desta glicoproteína na superfície das hemácias. Tendo em vista este fato, e que animais da subespécie Bos taurus taurus são mais susceptíveis à babesiose quando comparados à animais Bos taurus indicus, objetivou-se neste trabalho a detecção e quantificação do antígeno Duffy na superfície dos eritrócitos de bovinos empregando para tal, anticorpo policlonal que permitisse investigar se as diferenças na susceptibilidade são devido a diferentes níveis de expressão do antígeno Duffy nas hemácias. Ensaios de ELISA mostraram que o anticorpo produzido foi capaz de reconhecer o antígeno Duffy presente nas hemácias bovinas e a análise quantitativa não demonstrou diferença significativa na presença do mesmo. Estes resultados sugerem que a resistência maior dos zebuínos à babesiose não se deve à ausência de expressão, ou à presença em menor quantidade do antígeno Duffy na superfície de suas hemácias.Babesiosis is one of the most important diseases affecting livestock agriculture worldwide. Animals from the subspecies Bos taurus indicus are more resistant to babesiosis than those from Bos taurus taurus. The genera Babesia and Plasmodium are Apicomplexa hemoparasites and share features such as invasion of red blood cells (RBC). The glycoprotein Duffy is the only human erythrocyte receptor for Pasmodium vivax and a mutation which abolishes expression of this glycoprotein on erythrocyte surfaces is responsible for making the majority of people originating from the indigenous populations of West Africa resistant to P. vivax. The current work detected and quantified the Duffy antigen on Bos taurus indicus and Bos taurus taurus erythrocyte surfaces using a polyclonal antibody in order to investigate if differences in susceptibility to Babesia are due to different levels of Duffy antigen expression on the RBCs of these animals, as is known to be the case in human beings for interactions of Plasmodium vivax-Duffy antigen. ELISA tests showed that the antibody that was raised against Duffy antigens detected the presence of Duffy antigen in both subspecies and that the amount of this antigen on those erythrocyte membranes was similar. These results indicate that the greater resistance of B. taurus indicus to babesiosis cannot be explained by the absence or lower expression of Duffy antigen on RBC surfaces.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES