O gene da miogenina: sequenciamento em suínos e análise filogenética

• Autor(a) principal: Schierholt, Alex Sandro
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4706
• topic: Suíno; Miogenesis; Filogenia; Gene candidato; Genética molecular; Swine; Myogenesis; Phylogeny; Candidate gene; Molecular genetics; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::GENETICA E MELHORAMENTO DOS ANIMAIS DOMESTICOS

Meat production capacity is related to muscle fibers number show in newborn animals. The muscle fibers are formed in the myogenesis that takes place during the embryonic development, an event that is controlled in part by the MyoD gene family. The Myogenin gene is a member of this family and rules the expression of muscle specific genes. It has an important because when it is activated, the cells from the muscle tissue stop to multiply and it will be growing only in volume. It is considered than a candidate gene. The objectives of this study were to verify possible alterations in the nucleotide sequences of the Myogenin gene in swine from divergent breeds, and compare the sequence obtained in swine with others species that have this data in the Genbank, to study the evolutionary story of the gene in these species. The strategy used was to divide the gene in seven fragments that contain the three exons, two introns and the 3 and 5 regions of the gene. Two boars of the native breed Piau and 12 commercial sows were sequenciated. The results showed a highly conserved gene, with no polymorphism in the exons regions. The introns sequencing did not shown satisfactory results. Phylogenetic evaluation methods also prove the conservatory state of the gene. It was compared sequences from the species Sus scrofa (swine), Bos Taurus (cows), Ovis aries (sheeps), Homo sapiens (humans), Mus musculus (mice), Rattus norvegicus (rats), Gallus gallus (chickens) and Meleagris gallopavo (turkeys), verifying the nonsynonymous nucleotide substitution rate by the synonymous substitution rate in the sites. The results point out that probably the gene suffered an adaptive evolution in the Ruminantia group (B. Taurus and O. aries) after these species diverged from their common ancestral. In the other species, the gene seems to be evolving in a conservative way.