当前位置： SCI文献检索 > EVOLUTION & DEVELOPMENT期刊下所有文献 > Neurogenesis in the crustacean ventral nerve cord: homology of neuronal stem cells in Malacostraca and Branchiopoda?

Neurogenesis in the crustacean ventral nerve cord: homology of neuronal stem cells in Malacostraca and Branchiopoda?

Abstract：

:In Insecta and malacostracan Crustacea, neurons in the ventral ganglia are generated by the unequal division of neuronal stem cells, the neuroblasts (Nbs), which are arranged in a stereotyped, grid-like pattern. In malacostracans, however, Nbs originate from ectoteloblasts by an invariant lineage, whereas Nbs in insects differentiate without a defined lineage by cell-to-cell interactions within the neuroectoderm. As the ventral ganglia in entomostracan crustaceans were thought to be generated by a general inward proliferation of ectodermal cells, the question arose as to whether neuroblasts in Euarthropoda represent a homologous type of stem cell. In the current project, neurogenesis in metanauplii of the entomostracan crustaceans Triops cancriformis Fabricius, 1780 (Branchiopoda, Phyllopoda) and Artemia salina Linné, 1758 (Branchiopoda, Anostraca) was examined by in vivo incorporation of the mitosis marker bromodeoxyuridine (BrdU) and compared to stem cell proliferation in embryos of the malacostracan Palaemonetes argentinus Nobili, 1901 (Eucarida, Decapoda). The developmental expression of synaptic proteins (synapsins) was studied immunohistochemically. Results indicate that in the ventral neurogenic zone of Branchiopoda, neuronal stem cells with cellular characteristics of malacostracan neuroblasts are present. However, a pattern similar to the lineage-dependent, grid-like arrangement of the malacostracan neuroblasts was not found. Therefore, the homology of entomostracan and malacostracan neuronal stem cells remains uncertain. It is now well established that during arthropod development, identical and most likely homologous structures can emerge, although the initiating steps or the mode of generation of these structures are different. Recent evidence suggests that adult Entomostraca and Malacostraca share corresponding sets of neurons so that the present report provides an example that those homologous neurons may be generated via divergent developmental pathways. In this perspective, it remains difficult at this point to discuss the question of common patterns of stem cell proliferation with regard to the phylogeny and evolution of Atelocerata and Crustacea.

journal_name

Evol Dev

journal_title

Evolution & development

authors

Harzsch S

doi

10.1046/j.1525-142x.2001.003003154.x

keywords:

subject

Has Abstract

pub_date

2001-05-01 00:00:00

pages

154-69

issue

eissn

1520-541X

issn

1525-142X

journal_volume

pub_type

杂志文章

在线工具

Neurogenesis in the crustacean ventral nerve cord: homology of neuronal stem cells in Malacostraca and Branchiopoda?