Function and position determine relative proportions of different fiber types in limb muscles of the lizard Tropidurus psammonastes

Autor(es)

Pereira, Anieli G. ^{[1, 2]} ; Abdala, Virginia ^[3] ; Kohlsdorf, Tiana ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, FFCLRP, Dept Biol, Ribeirao Preto, SP - Brazil

^[2] Univ Fed Rio de Janeiro, Dept Genet, Rio De Janeiro, RJ - Brazil

^[3] Consejo Nacl Invest Cient & Tecn, Inst Biodiversidad Neotrop, San Miguel De Tucuman - Argentina

• Tipo de documento: Artigo Científico
• Fonte: ZOOLOGY; v. 118, n. 1, p. 27-33, FEB 2015.
• Citações Web of Science: 3

Resumo

Skeletal muscles can be classified as flexors or extensors according to their function, and as dorsal or ventral according to their position. The latter classification evokes their embryological origin from muscle masses initially divided during limb development, and muscles sharing a given position do not necessarily perform the same function. Here, we compare the relative proportions of different fiber types among six limb muscles in the lizard Tropidurus psammonastes. Individual fibers were classified as slow oxidative (SO), fast glycolytic (FG) or fast oxidative-glycolytic (FOG) based on mitochondrial content; muscles were classified according to position and function. Mixed linear models considering one or both effects were compared using likelihood ratio tests. Variation in the proportion of FG and FOG fibers is mainly explained by function (flexor muscles have on average lower proportions of FG and higher proportions of FOG fibers), while variation in SO fibers is better explained by position (they are less abundant in ventral muscles than in those developed from a dorsal muscle mass). Our results clarify the roles of position and function in determining the relative proportions of the various muscle fibers and provide evidence that these factors may differentially affect distinct fiber types. (C) 2014 Published by Elsevier GmbH. (AU)

• Processo FAPESP: 12/51012-6 - Morfologia e fisiologia comparadas entre duas das famílias mais especiosas de lagartos neotropicais: Liolaemidae versus Tropiduridae
• Beneficiário: Tiana Kohlsdorf
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 05/60140-4 - Evolução de diversidade fenotípica em lagartos tropicais: uma abordagem integrativa investigando diversos níveis de organização
• Beneficiário: Tiana Kohlsdorf
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores