RESUMO
The effects of different periods of starvation (1, 2, 3, and 4 weeks) and subsequent re-feeding (over a 4 week) on the compensatory growth performance and insulin-like growth factor I (IGF-I) mRNA expression in liver and white muscle were investigated in juvenile Persian sturgeon (Acipenser persicus). First, a fragment of 617 nucleotides coding for IGF-I was cloned from liver, which included an open reading frame of 486 nucleotides, encoding a 162 amino acid preproIGF-I. This is composed of a 45 aa for signal peptide, a 117 aa for the mature peptide comprising the B, C, A, and D domains, and a 47 aa for E domain. The mature Persian sturgeon IGF-I exhibits high sequence identities with other sturgeon species and teleost, ranging between 68 and 95 %. The pattern of IGF-I mRNA expression in the liver and white muscle was measured in response to different periods of starvation and subsequent re-feeding. Nutritional status influenced IGF-I mRNA expression pattern in both liver and muscle. IGF-I mRNA expression in the liver increased during starvation, before decreasing after re-feeding. Furthermore, white muscle IGF-I mRNA expression showed better responses to nutritional status and decreased following starvation and increased by re-feeding. However, changes in the expression of IGF-I mRNA were not significantly different between any of the treatments in both tissues. These data suggest that muscle and liver IGF-I mRNA expression do not have a regulatory role for somatic growth induced by compensatory growth in Persain sturgeon.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal/genética , Peixes/genética , Regulação da Expressão Gênica , Fator de Crescimento Insulin-Like I/genética , Sequência de Aminoácidos , Animais , Peso Corporal/genética , Clonagem Molecular , DNA Complementar/genética , Peixes/crescimento & desenvolvimento , Fator de Crescimento Insulin-Like I/química , Fator de Crescimento Insulin-Like I/metabolismo , Dados de Sequência Molecular , Pérsia , Filogenia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNARESUMO
Diploid gynogenesis was induced in ship sturgeon Acipenser nudiventris using UV-irradiated sperm from Siberian sturgeon Acipenser baerii. The optimal condition for the retention of the second polar body in ship sturgeon was determined to be 10 min after activation/fertilization in experiments. The temperature of cold shock and its duration were 2.5 °C and 30 min, respectively. A total of 30 gynogens of known parentage from experimental treatments were screened using microsatellite DNA analysis, and uniparental transmission in meiogens was confirmed. The results show that heterologous Siberian sturgeon sperm is applicable as UV-irradiated sperm for the induction of gynogenesis in ship sturgeon. This technique may recover the critically endangered sturgeon species that are becoming extinct.
