为探究CYP17-I基因在绿鳍马面鲀繁殖周期中的作用及其与性激素水平变化的相关性,实验首先通过SmartTMRace技术克隆得到了绿鳍马面鲀CYP17-I c DNA全长序列1 580 bp,编码511个氨基酸。通过半定量RT-PCR技术检测了CYP17-I基因的时空表达,...为探究CYP17-I基因在绿鳍马面鲀繁殖周期中的作用及其与性激素水平变化的相关性,实验首先通过SmartTMRace技术克隆得到了绿鳍马面鲀CYP17-I c DNA全长序列1 580 bp,编码511个氨基酸。通过半定量RT-PCR技术检测了CYP17-I基因的时空表达,并采用放射免疫测定法检测雄鱼和雌鱼血清睾酮(T)和雌二醇(E2)的含量变化。结果发现,CYP17-I在卵巢、精巢和脑中表达量较高,其次为胃、心脏、脾脏、肾脏,在垂体和鳃中也检测到了微弱表达。在周期表达中发现,无论在卵巢还是精巢中,CYP17-I基因的表达水平与血清T含量密切相关,呈明显周期性变化,最高值均出现在5月份的卵细胞或精子成熟期,而与血清E2含量无显著的相关性。研究表明,CYP17-I在鱼类繁殖周期中对雄性激素睾酮的生成起关键的调控作用。展开更多
The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium st...The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium stocking density, MSD: 8.0 kg/m^3; and high stocking density, HSD: 11.0 kg/m^3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower fi nal body weight and specifi c growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2(IGF-2), while the concentrations of serum growth hormone(GH) and insulin-like growth factor 1(IGF-1) decreased in the HSD group. The full-length cDNAs of G H and IGF-2 genes(995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor( GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively af fects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.展开更多
文摘为探究CYP17-I基因在绿鳍马面鲀繁殖周期中的作用及其与性激素水平变化的相关性,实验首先通过SmartTMRace技术克隆得到了绿鳍马面鲀CYP17-I c DNA全长序列1 580 bp,编码511个氨基酸。通过半定量RT-PCR技术检测了CYP17-I基因的时空表达,并采用放射免疫测定法检测雄鱼和雌鱼血清睾酮(T)和雌二醇(E2)的含量变化。结果发现,CYP17-I在卵巢、精巢和脑中表达量较高,其次为胃、心脏、脾脏、肾脏,在垂体和鳃中也检测到了微弱表达。在周期表达中发现,无论在卵巢还是精巢中,CYP17-I基因的表达水平与血清T含量密切相关,呈明显周期性变化,最高值均出现在5月份的卵细胞或精子成熟期,而与血清E2含量无显著的相关性。研究表明,CYP17-I在鱼类繁殖周期中对雄性激素睾酮的生成起关键的调控作用。
基金Supported by the National Special Research Fund for Non-Profit Sector(Agriculture)(No.201003055)
文摘The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium stocking density, MSD: 8.0 kg/m^3; and high stocking density, HSD: 11.0 kg/m^3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower fi nal body weight and specifi c growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2(IGF-2), while the concentrations of serum growth hormone(GH) and insulin-like growth factor 1(IGF-1) decreased in the HSD group. The full-length cDNAs of G H and IGF-2 genes(995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor( GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively af fects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.
