斑馬魚不僅是實驗室常用的模式動物,，而且是一種小型熱帶觀賞魚,，具有黑色和黃色條紋,，它的條紋是由黑色和黃色色素細(xì)胞組成，但是同類色素細(xì)胞為何能集合在一起形成花紋,？近日,，日本一項新研究探明了其原理。相關(guān)論文發(fā)表在2月10日的Science雜志上,。
大阪大學(xué)一個研究小組報告說,，斑馬魚體內(nèi)兩種顏色的色素細(xì)胞會互相排斥，而同色的色素細(xì)胞則更容易相互吸附，這樣的移動對于花紋的形成起到重要作用,。
此次研究中,，研究人員從斑馬魚體內(nèi)取出這兩種色素細(xì)胞，放到培養(yǎng)皿中觀察,。結(jié)果發(fā)現(xiàn),，如果是條紋非常清晰的斑馬魚，它的黃色色素細(xì)胞接觸到黑色色素細(xì)胞瞬間,，黑色色素細(xì)胞會立即“逃”向相反方向,。
這是由于兩種細(xì)胞接觸后，細(xì)胞膜的電性發(fā)生變化,，產(chǎn)生了排斥反應(yīng),。而相同顏色的色素細(xì)胞則容易吸附在一起。由于不斷重復(fù)這一過程,，色素細(xì)胞根據(jù)不同顏色分別聚集,，從而形成了花紋。但條紋不鮮明的變異個體,，它的色素細(xì)胞就不會發(fā)生這種反應(yīng),，黑色和黃色的細(xì)胞會一直混合在一起。
研究人員說,，其他動物的花紋形成原理應(yīng)該也與此類似,，今后他們將進一步研究動物花紋形成的普遍原理。（生物谷Bioon.com）
doi:10.1126/science.1212821
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Pigment Pattern Formation by Contact-Dependent Depolarization
Masafumi Inaba, Hiroaki Yamanaka, Shigeru Kondo
Although recent experimental studies have suggested that the interactions among the pigment cells play a key role in the skin pattern formation, details of the mechanism remain largely unknown. By using an in vitro cell culture system, we have detected interactions between the two pigment cell types, melanophores and xanthophores, in the zebrafish skin. During primary culture, the melanophore membrane transiently depolarizes when contacted with the dendrites of a xanthophore. This depolarization triggers melanophore migration to avoid further contact with the xanthophores. Cell depolarization and repulsive movement were not observed in pigment cells with the jaguar mutant, which shows defective segregation of melanophores and xanthophores. The depolarization-repulsion of wild-type pigment cells may explain the pigment cell behaviors generating the stripe pattern of zebrafish.
