两种体色瓯江彩鲤黑色素形成比较

Formation of melanin and mitfa in-situ in the Oujiang color common carp(Cyprinus carpio var.color)

摘要:

为了解瓯江彩鲤黑色图案的形成过程和黑色素合成重要基因mitfa（microphthalmia-associated transcription factor a）在该过程中的作用，进而探究瓯江彩鲤黑色图案形成的分子机制，观察了“大花”和“全红”两种体色瓯江彩鲤受精后24、36、48 h和出膜后1、2、3、5、10和15 d共9个时期黑色素细胞发育特征和黑色素形成过程，利用原位杂交技术检测mitfa基因的表达模式。发现在水温21~25℃条件下，“大花”中黑色素最早在受精后36 h出现于眼睛。孵化后3 d，黑色素开始在胚体上出现；孵化后5~15 d，黑色素细胞逐渐在头部、腹部、尾部集中出现和增加；而“全红”除眼睛外其他部位均未观察到黑色素。原位杂交结果表明，mitfa基因在“大花”中有黑色素分布位置出现明显杂交信号，孵化后5~10 d黑色素明显增加，mitfa基因杂交信号也增加；同时，mitfa基因“全红”体色的胚体无黑色素分布位置也能观察到明显的杂交信号。

Abstract:

In order to understand the formation of black pattern in Oujiang color common carp,and to learn the important function of pigment related gene. and further study the molecular mechanism of black patterns formation in Oujiang color common carp or other fishes, so in this study, the melanin development was first observed in RB and WR. Meanwhile, the in situ probe of mitfa was prepared for analysing the exprssion and localization of mitfa gene in the important period of melanin development, according to the observation of the development of melanin in RB and WR in 9 development periods. In RB, the melanin appeared in the eyes at 36 hpf firstly, the melanin was first observed on the body at 3 dph, then melanin appeared locally at tail, abdomen and dorsal. In WR, the melanin only happened in the eyes, no melanin was observed in other position. Whole-mount in situ hybridizaton mitfa gene showed that the hybridization signal appeared on the head and abdomen where melanin appeared. When the melanin significantly increased at 10 dph, hybridization signal increased and more obvious. But even these is no melanin in the body of WR, the mitfa gene hybridization signal also can be observed. This study suggests that mitfa gene plays an important role of melanin in Oujiang color common carp,but it is not responsible for the difference of black pattern between several Oujiang color common carp.