Navegando por Autor "Bruneli, Frank Angelo Tomita"
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Item Genetic diversity and population genetic structure of a guzerá (Bos indicus) meta-population.(2021) Peixoto, Maria Gabriela Campolina Diniz; Carvalho, Maria Raquel Santos; Egito, Andréa Alves do; Silva, Raphael Steinberg da; Bruneli, Frank Angelo Tomita; Machado, Marco Antônio; Santos, Fernanda Caroline dos; Cruz, Izinara Rosse da; Fonseca, Pablo Augusto S.The Brazilian Guzerá population originated from a few founders introduced from India. These animals adapted well to the harsh environments in Brazil, were selected for beef, milk, or dual-purpose (beef and milk), and were extensively used to produce crossbred animals. Here, the impact of these historical events with regard to the population structure and genetic diversity in a Guzerá meta-population was evaluated. DNA samples of 744 animals (one dairy, nine dual-purpose, and five beef herds) were genotyped for 21 microsatellite loci. Ho, He, PIC, Fis, Fit, and Fst estimates were obtained considering either farms or lineages as subpopulations. Mean Ho (0.73) and PIC (0.75) suggest that genetic diversity was efficiently conserved. Fit, Fis and Fst values (95% CI) pointed to a low fixation index, and large genetic diversity: Fit (Farms = 0.021–0.100; lineages = 0.021–0.100), Fis (Farms = –0.007–0.076; lineages = −0.014–0.070), and Fst (Farms = 0.0237–0.032; lineages = 0.029– 0.038). The dual-purpose herds/selection lines are the most uniform subpopulation, while the beef one preserved larger amounts of genetic diversity among herds. In addition, the dairy herd showed to be genetically distant from other herds. Taken together, these results suggest that this Guzerá meta-population has high genetic diversity, a low degree of population subdivision, and a low inbreeding level.Item Phenotypic variation in milk fatty acid composition and its association with stearoyl-CoA desaturase 1 (SCD1) gene polymorphisms in Gir cows.(2023) Matosinho, Carolina Guimarães Ramos; Fonseca, Pablo Augusto Souza; Peixoto, Maria Gabriela Campolina Diniz; Cruz, Izinara Rosse da; Lopes, Fernando César Ferraz; Zózimo, Thalía Rodrigues de Souza; Vercesi Filho, Aníbal Eugênio; Bruneli, Frank Angelo Tomita; Carvalho, Maria Raquel Santos; Gama, Marco Antonio SundfeldIndividual variation in milk fatty acid (FA) composition has been partially attrib- uted to stearoyl-CoA desaturase 1 (SCD1) gene polymorphisms in taurine breeds, but much less is known for Zebu breeds. This study investigated the phenotypic variation in milk FA composition, and the influence of SCD1 variants on this trait and on milk fat desaturase indices (DI) in Gir cows. The functional impact of SCD1 variants was predicted using bioinformatics tools. Milk and blood samples were collected from 312 cows distributed in 10 herds from five states of Brazil. SCD1 variants were identified through target sequencing, and milk FA composi- tion was determined by gas chromatography. Phenotypic variation in milk FA composition fell within the range reported for taurine breeds, with SCD18 index showing the lowest variation among the DI. Fourteen SCD1 variants were identi- fied, six of which not previously described. Regarding the A293V polymorphism, all cows were homozygous for the C allele (coding for alanine), whereas all gen- otypes were detected for the second SNP affecting the 293 codon (G>A), with compelling evidence for functional effects. Significant associations (based on raw p-values) were found between this SNP and C12:0, cis-9, trans-11 CLA and short- chain FA, and between another SNP (rs523411937) and C15:0 and odd-chain lin- ear FA. A new SNP on Chr26:21277069 was associated with trans-11 C18:1, cis-9, trans-11 CLA, C18:3 n-3 and n-3 FA. These findings indicate that SCD1 polymor- phisms also contributes to the phenotypic variation in milk FA composition of Gir cows, with potential use in their breeding programmes.