Investigação da diversidade proteica em bovinos

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Estudos de polimorfismos genéticos em animais domésticos

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Investigação da diversidade proteica em bovinos

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Estudo da variabilidade genética em rebanho bovino da raça Ibajé

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Estudo da variabilidade genética em rebanho bovino da raça Ibajé

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Estudos de polimorfismos genéticos em animais domésticos

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BIOCHEMICAL POLYMORPHISMS IN SHEEP AND THEIR POTENTIAL USE FOR PATERNITY TESTS

The genetic variability of 22 protein loci was investigated in two sheep flocks: 22 females Romney Marsh and 124 animals derived from crossbreeding between Romney Marsh and Merino Booroola, reared by the Brazilian Agricultural Research Corporation (Empresa Brasileira de Pesquisa Agropecuária -EMBRAPA, Bagé, RS, Brazil). Eight loci were polymorphic; the others showed no variation. The usefulness of the eight plymorphic systems (Cat, DIA I, EP-1, EsA, HbB, ME, Tf, and X Prot.) in parentage tests was analyzed. The probability to find two random identical animals in each breed was estimated as 1:1000. The efficiency of these proteins for exclusion of one of two possible sires in parentage tests was about 77% both for Romney Marsh and Romney/ Booroola flocks. Although parentage tests in sheep have not been enforced in Brazil up to now, the establishment of this technique is important for the prevention of non-paternity on the excellent rams

Mitochondrial control region genetic diversity and maternal ancestry of a Brangus-Ibage cattle populations

The genetic diversity of 277 nucleotides in the mitochondrial DNA control region (nt 15,964 to 16,240 in reference sequence) was analyzed in crossbreed beef cattle (Brangus-Ibage, 5/8 Bos primigenius taurus x 3/8 Bos primigenius indicus) as well as in some Nellore samples (B. p. indicus). Fifty-seven mutations were found in Brangus-Ibage comprising 18 haplotypes (haplotype diversity, h = 0.851 ± 0.041 and nucleotide diversity, ntd = 0.009 ± 0.006) and 66 in Nellore (h = 1.00 ± 0.27, ntd = 0.014 ± 0.012). These data indicated sequence identities of 99.6 and 92.1% between the B. p. taurus’ reference sequence and Brangus-Ibage and Nellore, respectively. The comparison of our data with sequence data for 612 individuals recovered from GenBank showed a total of 205 haplotypes defined by 99 polymorphic sites. Most of the variability (53%) was due to differentiation within breeds. The phylogenetic tree constructed using the neighbor-joining method showed clearly the well-known dichotomy between B. p. taurus and B. p. indicus. The Brangus-Ibage clustered with B. p. taurus lineages; however, the displacement of Nellore from B. p. indicus branch probably indicates a substantial B. p. taurus maternal ancestry in some Nellore samples (obtained from GenBank) and reflects the primarily male-driven introduction of this breed in Brazil

Caracterização genética de uma população de bovinos brangus-ibagé –polimorfismos bioquímicos e eficiência reprodutiva

Técnicas bioquímicas foram utilizadas para determinar a variabilidade genética numa população de bovinos da raça Brangus-Ibagé com relação a 18 sistemas protéicos sangüíneos: Hemoglobina - Cadeia b (Hb), Albumina (Alb), Amilase (Am), Transferrina (Tf), Anidrase Carbônica (CA), Ceruloplasmina (Cp), Enzima Málica (ME), Diaforase I and II (Dia I and Dia II), Macroglobulina a2 lenta (Ap), Fosfatase Ácida (ACP), Esterase B and D (EstB and EstD), Fosfogliconato Desidrogenase (PGD), Glicose-6-Fosfato Desidrogenase (G-6-PD), Glicose- Fosfato-Isomerase (GPI), Superóxido Dismutase (SOD) e Glioxalase I (GLO). O percentual de locos polimórficos foi estimado em 0,27, o número médio de alelos foi 1,33 e a heterozigosidade média foi de 0,07. Houve boa concordância entre a heterozigosidade média observada e a esperada. A população apresentou-se em equilíbrio de Hardy-Weinberg em todos os sistemas. Também foram determinados três parâmetros de eficiência reprodutiva: idade média ao primeiro parto (1152,15 ± 166,60 dias), intervalo médio entre partos (539,23 ± 124,10 dias) e peso médio da vaca ao primeiro parto (391,02 ± 37,59kg). Não se encontrou nenhuma associação entre os polimorfismos protéicos e os parâmetros de eficiência reprodutiva.Biochemical techniques were used to investigate the genetic variability in a Brangus-Ibage population by determining allele frequencies of 18 blood protein systems: Hemogloin b- Chain (Hb), Albumin (Alb), Amylase (Am), Transferrin (Tf), Carbonic Anhydrase (CA), Ceruloplasmin (Cp), Malic Enzyme (ME), Diaphorase I and II (Dia I and Dia II), Slow Alpha 2 Macroglobulin (Ap), Acid Phosphatase (ACP), Esterase B and D (EstB and EstD), Phosphogluconate Dehydrogenase (PGD), Glucose-6-Phosphate Dehydrogenase (G-6-PD), Glucose- Phosphate-Isomerase (GPI), Superoxide Dismutase (SOD) and Glyoxalase I (GLO). The percentage of polymorphic loci were estimated at 0.27, the mean number of alleles was 1.33 and the mean heterozygosity was 0.07. There was a good agreement between expected and observed heterozygosity values. The population was in agreement with Hardy-Weinberg expectations in all systems. Reproductive records allowed to estimate three parameters of reproductive efficiency: mean age at first calving (1152.15 ± 166.60 days), mean calving interval (539.23 ± 124.10 days) and mean weight at first calving (391.02 ± 37.59kg). No relationship was found between reproductive efficiency and genetic systems