Genetic study on the three color variations in sea cucumber, Stichopus japonicus

有三种颜色变体类型，即红色类型、绿色类型和黑色类型。这些类型包括在一个物种中，但它们的栖息地和繁殖季节并不总是相同的。然而，关于它们的颜色变化、生态特性、生长等方面的研究很少，因为它们的生物学特性，日本海参是一个科学上熟悉而又陌生的物种，本研究旨在对日本海参的颜色变异进行定量和定性的评价，利用同工酶标记基因估计遗传变异和分化，利用微卫星DNA标记基因阐明日本海参的生殖隔离事实。（1）红型与绿型之间、红型与黑型之间的颜色系统L^*a^*B^* 分布不连续，差异明显，而绿型与黑型之间的颜色系统L ^* a ^* b ^* 分布不连续，差异不明显。（2）不同的颜料w 关于我们 在红型和绿型之间以及红型和黑型之间也观察到，但在绿型和黑型之间没有观察到。（3）三种类型的同工酶基因均具有较高的遗传变异性。（4）等位基因频率在红型与绿型之间、红型与黑型之间存在显著差异，而在绿型与黑型之间差异不显著。（5）筛选出20个微卫星标记，并通过交配试验研究了它们的遗传控制作用。（6）利用上述微卫星标记基因，在红型与绿型、红型与黑型之间检测到显著差异，而在绿色型与黑型之间检测不到显著差异，据此可将红型与其它两种类型区分开来，并将红型识别为新亚种。在颜色测量、色素沉着、同工酶基因和微卫星标记基因上，绿型和黑型之间没有差异。这两种类型可能属于同一地区的同一种、同一种群。少

There are three color variant types, namely red-type, green-type and black type. These types are including in one species, but their habitat and breeding seasons are not always same. However few studies regarding to their color variation, ecological characteristics, growth, etc., have been carried out because of their biological characteristics. Japanese sea cucumber is familiar species but strange species scientifically.The aims of the present study are to evaluate the color variation quantitatively and qualitatively, to estimate genetic variability and divergence using isozyme marker genes, and to elucidate the fact of reproductive isolation using microsatellite DNA marker genes, which are developed by the present study.Following results are obtained ;(1)Discontinuous distribution and clear difference in the color system"L^*a^*b^* was observed between the red-type and green-type, and between the red-type and black-type, but not between green-type and black type.(2)Different pigment w … More as also observed between the red-type and green-type, and between the red-type and black type, but not between green-type and black-type.(3)High genetic variability of isozyme genes was observed in the three types.(4)Significant differences in allele frequencies were observed between the red-type and green-type, and between the red-type and black-type, but not between green-type and black-type.(5)Twenty microsatellite markers were developed and their genetic control was elucidate by mating experiments.(6)Using the above microsatellite marker genes, significant differences were detected between the red-type and green-type, and between the red-type and black type, but not between green type and black-type.From the above results, the red-type should be distinguished from the other two types, and the red-type should be recognized as new subspecies. On the other side, in any of color measurements, pigmentation, isozyme genes and microsatellite marker genes, no difference was observed between green-type and black-type. It could be interpreted that the two types are included in the same species and the same population in the same area. Less