牙鲆仔鱼核酸与生长关系的研究

Relationship between Nucleic Indicators and Growth in Larvae of Japanese Flounder Paralichthys olivaceus

随机采取不同日龄健康的牙鲆仔鱼,用电子目镜和天平测定其全长(L)、体质量(m),运用整体匀浆法测定鱼体中核酸和总蛋白浓度、RNA/DNA(a)比值和总蛋白/DNA比值(b),研究了牙鲆仔鱼的生长,DNA、RNA和总蛋白的变化规律,探讨了核酸、总蛋白和生长的关系。试验结果表明,牙鲆仔鱼体质量、全长与RNA/DNA比值均呈线性负相关,关系式分别为m=-19.85 a+82.79(r2=0.89,P<0.01),L=-7.41 a+33.53(r2=0.85,P<0.05)。上述关系式说明,牙鲆仔鱼时期的生长以细胞增殖为主,大量消耗前期合成的蛋白质。牙鲆仔鱼体质量、全长与总蛋白/DNA比值也呈线性负相关,关系式分别为m=-0.61 b+34.54(r2=0.93,P<0.01),L=-0.22 b+15.33(r2=0.86,P<0.01)。随着牙鲆仔鱼养殖日龄的增加,总蛋白/DNA比值下降的幅度大于RNA/DNA比值。核酸指标能从细胞水平上分析仔鱼的生长。

Total length（L）and body weight（m）,concentrations of nucleic acid,and protein,RNA/DNA ratio（a）,and protein/DNA ratio（b）were measured in larvae of Japanese flounder Paralichthys olivaceus by whole homogenate method and by electron microscope to evaluate the relationship between nucleic indicators and growth in larval Japanese flounder.It was found that body weight and total length were negatively correlated with RNA/DNA ratio,with an equation as m=-19.85 a ＋ 82.79（r^2= 0.89,P〈0.01）,and as L=-7.41a＋33.53（r^2=0.85,P〈0.05）,indicating that the growth of Japanese flounder larvae was primarily involved in hyperplasia and in exhaustion of protein synthesized during the early developmental stage.Body weight and total length were also negatively correlated with protein：DNA ratio,with an equation m=-0.61b＋34.54（r^2=0.93,P〈0.01）and L=-0.22b＋15.33（r^2=0.86,P〈0.01）.There was larger decrease scope in the protein/DNA ration than that in the RNA/DNA ratio as the larvae elapse in culture.The findings suggest that nucleic indicators be used to evaluate growth rates of larval Japanese flounder on a cellular level.