Papers by Marco Antonio Cardoso Silva
Arquivo Brasileiro De Medicina Veterinaria E Zootecnia, 2005
The association between BoLA-DRB3.2 alleles identified by PCR-RFLP and milk production in Gir bre... more The association between BoLA-DRB3.2 alleles identified by PCR-RFLP and milk production in Gir breed was studied using molecular and phenotypic data of 424 Gir cows. Genetic data consisted of animal genotypes for BoLA-DRB3.2 alleles and 305-day-milk-yield. The association between BoLA-DRB3.2 alleles and a putative QTL affecting the trait was investigated by mixed model with an animal model. BoLA-DRB3.2 locus was found to be highly polymorphic in Gir breed, showing seven alleles (BoLA-DRB3.2*4, *8, *11, *19, *28, *41 e *48) that have not been yet described in Zebu animals. Two BoLA-DRB3 alleles (*16 e *29) were significantly associated with milk production, suggesting that BoLA-DRB3.2 locus itself or a linked QTL influences 305-day-milk yield of Gir cows.
Genetics and Molecular Research 5 (3): 513-524 (2006) FUNPEC-RP www.funpecrp.com.br M.L. Martine... more Genetics and Molecular Research 5 (3): 513-524 (2006) FUNPEC-RP www.funpecrp.com.br M.L. Martinez et al. 514 Genetics and Molecular Research 5 (3): 513-524 (2006) www.funpecrp.com.br
Arquivo Brasileiro De Medicina Veterinaria E Zootecnia, 2004
A study was carried out by simulation to evaluate the efficiency and robustness of the random mod... more A study was carried out by simulation to evaluate the efficiency and robustness of the random model approach for estimation of the QTL location and variance components in an outbred population with full-sib family structure. Two QTL were positioned in the chromosome in the same interval, in adjacent and at no adjacent intervals. The population was created with different sizes and numbers of families and variances due to QTL in a trait with h2 = 0.25. The estimations of QTL parameters (locations and variance components) were based on the sib-pair approach. The proportions of genes identical-by-descent (IBD) at the two QTL were estimated from the IBD at two flanking markers. The most important factors afeccting the estimates of QTL parameters and power of detection were the proportion of variance due to QTL, and the number and size of the full-sibs families. Given a sufficient number of families and high proportions of genetic variance due to QTL, the random model approach can detect a QTL with high power and provides accurate estimates of the QTL position if there are no two QTL in the same interval.
![Research paper thumbnail of Mapping of quantitative trait loci controlling tick [Riphicephalus (Boophilus) microplus] resistance on bovine chromosomes 5, 7 and 14: Mapping of QTL controlling tick resistance](https://attachments.academia-assets.com/49087798/thumbnails/1.jpg)
Animal Genetics, 2007
Differences in domestication and selection processes have contributed to considerable phenotypic ... more Differences in domestication and selection processes have contributed to considerable phenotypic and genotypic differences between Bos taurus and Bos indicus cattle breeds. Of particular interest in tropical and subtropical production environments are those genetic differences between subspecies that underlie the phenotypic extremes in tolerance and susceptibility to parasite infection. In general, B. taurus cattle are more susceptible to ectoparasites than B. indicus cattle in tropical environments, and much of this difference is under genetic control. To identify genomic regions involved in tick resistance, we developed a B. taurus × B. indicus F2 experimental population to map quantitative trait loci (QTL) for resistance to the Riphicephalus (Boophilus) microplus tick. About 300 individuals were measured for parasite load in two seasons (rainy and dry) and genotyped for 23 microsatellite markers covering chromosomes 5, 7 and 14. We mapped a suggestive chromosome-wide QTL for tick load in the rainy season (P < 0.05) on chromosome 5. For the dry season, suggestive (P < 0.10) chromosome-wide QTL were mapped on chromosomes 7 and 14. The additive effect of the QTL on chromosome 14 corresponds to 3.18% of the total observed phenotypic variance. Our QTL-mapping study has identified different genomic regions controlling tick resistance; these QTL were dependent upon the season in which the ticks were counted, suggesting that the QTL in question may depend on environmental factors.
: Incêndio, biomas do Brasil, Queimadas SUMÁRIO: Introdução e Importância do tema; Biomas do Bras... more : Incêndio, biomas do Brasil, Queimadas SUMÁRIO: Introdução e Importância do tema; Biomas do Brasil; Histórico da Ocupação Humana: queimadas e incêndio no Brasil; Incêndios, queimadas e o desenvolvimento sustentável; Sistema Federativo no Brasil e SISNAMA; Legislação e Programas Federais de Prevenção contra Incêndios; Legislação e Programas do Estado de Minas Gerais de Prevenção contra Incêndios; Conclusão; Referências.
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Papers by Marco Antonio Cardoso Silva