title: Morphology and muscle gene expression in GIFT and Supreme Nile tilapia varieties reared in two cultivation systems.
abstract: Tissue growth in most fishes occurs by muscular hyperplasia and hypertrophy, which are influenced by different regulatory factors, such as myostatin. The current study evaluated the influence of cultivation in hapas and earthen ponds on the diameter of white muscle fibers and on the myostatin (MSTN-1) gene in GIFT and Supreme varieties of tilapia. Fish of both varieties were reared for 204 days and then divided into four developmental stages. White muscle samples, corresponding to 100 fibers per slide, were collected from the middle region of fish of each variety and cultivation system, and were measured and divided into two classes representing hyperplasia and hypertrophy. Samples were subjected to real-time PCR to analyze gene expression. Hyperplasia decreased during the developing stages, coupled with increased hypertrophy. There was a higher rate of hypertrophy in fish raised in earthen ponds when compared to those raised in hapas, during juvenile and developing phases, and greater hypertrophic growth was observed in GIFT specimens when compared to Supreme specimens in earthen ponds. Since increased MSTN-1 gene expression was observed in GIFT specimens during the developing phase in pond cultivations, and in Supreme tilapia in hapas, MSTN-1 expression is related to greater hypertrophy. These results demonstrate the capacity for increased muscle growth in earthen pond cultivation in which the GIFT variety developed best. How the environment affects the growth of different tilapia varieties may be employed to optimize culture management and genetic improvement programs. Further investigations should aim to describe mechanisms affecting muscle growth and development.
authors.affiliation: Departamento de Zootecnia, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: E C S
authors.initials: EC
authors.lastname: Lima
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brasil.
authors.forename: J A
authors.initials: JA
authors.lastname: Povh
authors.affiliation: Departamento de Medicina Veterinária Preventiva, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: R A A
authors.initials: RA
authors.lastname: Otonel
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: J H
authors.initials: JH
authors.lastname: Leonhardt
authors.affiliation: Departamento de Medicina Veterinária Preventiva, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: A A
authors.initials: AA
authors.lastname: Alfieri
authors.affiliation: Departamento de Medicina Veterinária Preventiva, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: S A
authors.initials: SA
authors.lastname: Headley
authors.affiliation: Departamento de Zootecnia, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: F P
authors.initials: FP
authors.lastname: Souza
authors.affiliation: Departamento de Zootecnia, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: A R
authors.initials: AR
authors.lastname: Poveda-Parra
authors.affiliation: Departamento de Zootecnia, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: P J
authors.initials: PJ
authors.lastname: Furlan-Murari
authors.affiliation: Departamento de Zootecnia, Programa de Pós-Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil nmlopera@uel.br.
authors.forename: N M
authors.initials: NM
authors.lastname: Lopera-Barrero
mesh_terms: D000818:Animals; D017756:Aquaculture / Q000379:methods*; D023681:Cichlids / Q000235:genetics / Q000254:growth & development*; D029941:Fish Proteins / Q000235:genetics; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D018482:Muscle, Skeletal / Q000254:growth & development / Q000648:ultrastructure*; D055435:Myostatin / Q000235:genetics*; D061005:Ponds
chemical_list: D029941:Fish Proteins; D055435:Myostatin