Stollewerk Angelika, Tautz Diethard, Weller Mathias
Abteilung fuer Evolutionsgenetik, Institut fuer Genetik, Universitaet zu Koeln, Weyertal 121, 50931 Koeln, Germany.
Arthropod Struct Dev. 2003 Aug;32(1):5-16. doi: 10.1016/S1467-8039(03)00041-0.
While there is a detailed understanding of neurogenesis in insects and partially also in crustaceans, little is known about neurogenesis in chelicerates. In the spider Cupiennius salei Keyserling, 1877 (Chelicerata, Arachnida, Araneae) invaginating cell groups arise sequentially and in a stereotyped pattern comparable to the formation of neuroblasts in Drosophila melanogaster Meigen, 1830 (Insecta, Diptera, Cyclorrhapha, Drosophilidae). In addition, functional analysis revealed that in the spider homologues of the D. melanogaster proneural and neurogenic genes control the recruitment and singling out of neural precursors like in D. melanogaster. Although groups of cells, rather than individual cells, are singled out from the spider neuroectoderm which can thus not be homologized with the insect neuroblasts, similar genes seem to confer neural identity to the neural precursor cells of the spider. We show here that the pan-neural genes snail and the neural identity gene Krüppel are expressed in neural precursors in a heterogenous spatio-temporal pattern that is comparable to the pattern in D. melanogaster. Our data suggest that the early genetic network involved in recruitment and specification of neural precursors is conserved among insects and chelicerates.
虽然人们对昆虫以及部分甲壳类动物的神经发生有详细的了解，但对于螯肢动物的神经发生却知之甚少。在1877年命名的蜘蛛（Cupiennius salei Keyserling，螯肢动物门、蛛形纲、蜘蛛目）中，内陷细胞群按顺序出现，且呈现出一种固定模式，类似于1830年命名的黑腹果蝇（Drosophila melanogaster Meigen，昆虫纲、双翅目、环裂亚目、果蝇科）中神经母细胞的形成。此外，功能分析表明，在蜘蛛中，黑腹果蝇的神经原性基因和神经发生基因的同源物像在黑腹果蝇中一样，控制着神经前体细胞的募集和分离。虽然从蜘蛛神经外胚层中分离出的是细胞群而非单个细胞，因此无法与昆虫神经母细胞进行同源化，但相似的基因似乎赋予了蜘蛛神经前体细胞神经身份。我们在此表明，泛神经基因蜗牛和神经身份基因Krüppel在神经前体细胞中以异质的时空模式表达，这与黑腹果蝇中的模式相当。我们的数据表明，参与神经前体细胞募集和特化的早期遗传网络在昆虫和螯肢动物中是保守的。
