Genesis of segmental identity in the leech nervous system.
Genesis of segmental identity in the leech nervous system.
复制标题
水蛭神经系统节段同一性的起源。
DOI：
10.1007/978-3-0348-9219-3_5
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Macagno,ER
中科院分区：
文献类型：
--
作者：
Aisemberg,GO;Wong,VY;Macagno,ER
触角足类同源框基因可能在无脊椎动物神经元身份的规范中发挥作用。药用水蛭是一种非常适合在已识别神经元水平上分析这些基因的物种，它含有许多触角足类和相关基因的同源物。详细检查了水蛭中枢神经系统中四个同源盒基因的表达模式。Lox1 在早期神经节形成期间在每个节段中存在的一对瞬时神经元中表达，在后期，在每个节段中的 15-20 对神经元中表达。Lox2 在中体后三分之二的重复神经元中表达 25-30 对。Lox4 存在于中体后半部分的 20-30 对重复神经元中，在Lox6 在第三食管下神经节的 15-20 对神经元和更多后神经节的较少细胞中表达。表达这些同源框基因的神经元子集不同但重叠。理论上，Loxgenes 的组合可以产生足够的变异性来指定水蛭神经节中的所有中枢神经元。
TheAntennapedia-class homeobox genes are likely to play a role in the specification of neuronal identities in invertebrates. The leechHirudo medicinalis, a species well-suited for the analysis of these genes at the level of identified neurons, contains homologs of manyAntennapedia-class and related genes. The expression pattern in the central nervous system of four leech homebox genes was examined in detail.Lox1is expressed during early gangliogenesis in one pair of transient neurons present in every segment and, at later stages, in 15–20 pairs of neurons per segment.Lox2is expressed in 25–30 pairs of neurons repeated in the posterior two-thirds of the midbody.Lox4is present in 20–30 pairs of iterated neurons in the posterior half of the midbody, and in smaller subset of them in more anterior ganglia.Lox6is expressed in 15–20 pairs of neurons of the third subesophageal neuromere and in fewer cells of more posterior ganglia. The subsets of neurons that express these homeobox genes are different but overlapping. Combinations ofLoxgenes could in theory generate enough variability to specify all central neurons in a leech ganglion.