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- Single-Strand Conformation Polymorphism (SSCP) analysis of alfas1-casein, beta-casein and k-casein genes in Charnequeira Portuguese indigenous goat breedPublication . Bonifácio, C.; Santos, Ingrid; Belo, Carmona; Cravador, A.The DNA from eighty goats belonging to the indigenous portuguese caprine breed Charnequeira, ecotype from Beira Baixa (Beiroa), was analysed. Single-strand conformation polymorphisms were identified at exon 9 and at exons 10-11 of the as1-casein gene and at exon 4 of the kcasein. The b-casein gene was found monomorphic at exon 7 in this population sample. The establishment of an association of some of these SSCP polymorphisms with milk production and protein and fat content was attempted.
- Association of milk traits with SSCP polymorphisms at the growth hormone gene in the Serrana goatPublication . Marques, P. X.; Pereira, M.; Marques, MR; Santos, Ingrid; Belo, Carmona; Renaville, Robert; Cravador, A.The present study suggests the existence of an association between milk production traits and genetic polymorphisms at the growth hormone (GH) gene in the Portuguese indigenous Serrana goat. TheDNAfrom 229 animals of two ecotypes (Jarmelista and Ribatejano)was analysed by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique revealing a high degree of genetic polymorphism at the goat GH (gGH) gene. Two conformation patterns were detected in exons 1 and 2, 6 in exon 3, 10 in exon 4 and 5 in exon 5. The evaluation of an association effect between these SSCP patterns with milk, fat and protein yields and fat and protein percentages suggests a positive effect of pattern A/B of exon 4 for Ribatejano ecotype and of pattern A/B of exon 2 for Jarmelista ecotype with milk yield (P < 0.05) and of pattern A/B of exon 1 and pattern B/B of exon 2 with protein percentage (P < 0.05) for Ribatejano ecotype. The results support the hints suggested by previous studies of the importance of the gGH gene as a candidate gene for marker-assisted selection in goat breeds and suggest that exon 4 is a preferential target for further investigation on mutations that influence milk yield variation.
- Ovis aries POU1F1 gene: cloning, characterization and polymorphism analysisPublication . Bastos, Estela; Santos, Ingrid; Parmentier, I.; Castrillo, José Luís; Cravador, A.; Guedes-Pinto, Henrique; Renaville, RobertPOU1F1 (PIT-1/GHF-1) is a transcription factor with critical role in the transcriptional regulation of multiple genes in the pituitary and also important for the survival, differentiation and proliferation of three pituitary cell types. To understand the regulation of POU1F1 gene in Ovis aries we report its cloning, sequencing and characterization. The sequenced 5787 bp included six exons and two complete introns. Ovine POU1F1 gene has a high level of conservation with its bovine, human and rat counterparts showing 98.2%, 91.2% and 86.2% of similarity at the coding level, respectively. All six exons were analyzed for polymorphism detection in 100 animals of the Portuguese indigenous ovine breed ‘Churra da Terra Quente’. One polymorphism was found at codon 58 in exon 2, in one allele of 4 animals leading to a change from cysteine to tyrosine (2% allelic frequency). In exon 3 two polymorphisms were detected: a G to A transition altering a glycine to an asparagine at codon 89 in one allele of one animal (0.5% allelic frequency) and another G to A transition at codon 105 converting an alanine into a threonine in one allele of 3 animals (1.5% allelic frequency). These polymorphisms might change the structure of the POU1F1 protein and modify gene-expression. In intron 4, an A to G transition was detected in one allele of six animals (3% allelic frequency). Exons 1, 4 and 6 showed no polymorphisms.
- Effects of genetic polymorphisms at the growth hormone gene on milk yield in “Serra da Estrela” sheepPublication . Marques, M. Rosário; Santos, Ingrid; Carolino, N.; Belo, Carmona; Renaville, Robert; Cravador, A.The five exons and the 5' and 3'-untranslated regions (5'-UTR and 3'-UTR) of the oGH gene were screened for mutations using PCR-single strand conformation polymorphism (PCR-SSCP) procedures in 523 Serra da Estrela ewes and were found to be highly polymorphic. The region extending across and between the GH2-N and GH2-Z copies was sequenced allowing the design of primers for the specific PCR amplification of each copy. These were cloned and sequenced in 20 animals representative of all SSCP patterns. The corresponding genotypes were established for each copy following nucleotide sequencing of SSCP alleles. Twenty-four polymorphic sites were found at the GH2-N (or GH1) and fourteen at the GH2-Z copies. Eight amino acid substitutions were predicted at the GH2-N and six at the GH2-Z copies. Milk yield adjusted to 150 lactation days was analysed for the genotype of each oGH gene copy taken separately or together (associated genotypes) by restricted maximum likelihood (REML) through a univariate best linear unbiased prediction (BLUP) animal model with repeated measures. Significant associations between genotypes and milk yield were observed. Within GH2-N genotypes there was a milk yield differential of 21.4+/-0.2 l/150 d between the most (N7) and the least (N5) productive ones. Within GH2-Z genotypes there was a differential of 21.6+/-0.2 l/150 d between the most (Z8) and the least (Z1) productive ones. The effect of associated GH2-N and GH2-Z genotypes revealed a differential of 39.6+/-0.3 l/150 d between the most (N1+Z7) and the least (N3+Z2) productive associated genotypes. The results show that GH2-N and GH2-Z genotypes significantly affect milk yield in Serra da Estrela ewes. Moreover, the apparent joint effect of GH2-N and GH2-Z genotype could improve milk yield in 25% as compared with the mean milk production of the analysed population.
- Polymorphisms at the five exons of gowth hormone gene in the Algarvia Goat. Possible association with milk traitsPublication . Malveiro, Elisabete; Pereira, M.; Marques, P. X.; Santos, Ingrid; Belo, Carmona; Renaville, Robert; Cravador, A.The present preliminary study attempts to establish associations between milk production traits and genetic polymorphisms at the GH gene in the Algarvia goat. The DNA of 108 goats of the indigenous Portuguese Algarvia breed was evaluated.
- Association between SSCPs at Algarvia goat GH and milk traitsPublication . Malveiro, Elisabete; Marques, P. X.; Santos, Ingrid; Belo, Carmona; Cravador, A.The DNA from one hundred eight goats belonging to the indigenous portuguese Algarvia breed was analysed. Single-strand conformation polymorphismÕs (SSCP) were identified at the five exons of the goat Growth Hormone (gGH) gene. Two conformational patterns were found in each of exons 1 and 2, four in exon 3, seven in exon 4 and five in exon 5. The establishment of an association of these SSCP patterns with milk, fat and protein production, and fat and protein content was attempted. Patterns A, F and D of exons 2, 4 and 5, respectively, are positively associated with milk, fat and protein production (p<0.05). Pattern A of exon 2 is also positively associated with fat content (p<0.05).