Molecular diversity in zebrafish NCAM family: Three members with different VASE usage and distinct localization
Molecular diversity in zebrafish NCAM family: Three members with different VASE usage and distinct localization
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DOI：
10.1006/mcne.2001.1007
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发表时间：
2001-07-01
影响因子：
3.5
通讯作者：
Yoshihara, Y
中科院分区：
文献类型：
--
作者：
Mizuno, T;Kawasaki, M;Yoshihara, Y
脊椎动物中的NCAM及其相关分子、海兔中的apCAM、果蝇中的Fasciclin II和哺乳动物中的OCAM在大脑发育和功能的各个方面发挥着关键作用。在本研究中，我们鉴定并鉴定了斑马鱼NCAM基因家族的三个成员，分别为zNCAM、zOCAM和zPCAM。有三个分子表现出相似的结构域结构：一个氨基末端信号肽，五个免疫球蛋白样结构域，两个纤维连接蛋白III型样结构域，一个跨膜片段和一个羧基末端细胞质区域。一个新的分子zPCAM与zNCAM的亲缘关系最近，氨基酸同源性为66%。ZPCAM胞外区的多样性是通过插入两种不同类型的可变或剪接外显子而产生的。原位杂交分析表明，在发育早期的中枢和外周神经系统中，有3个分子以区域特异性和细胞类型特异性的方式表达。例如，zPCAM显示出神经丝特异的节段性表达模式，而zOCAM首先出现在前脑中特定的次级神经元簇中。这些结果表明，NCAM基因家族的每个成员在斑马鱼神经系统中功能神经元网络的形成和维持中发挥着不同的作用。
NCAM in vertebrates and its related molecules, apCAM in Aplysia, fasciclin II in Drosophila, and OCAM in mammals, play key roles in various aspects of brain development and functions. In this study, we have identified and characterized three members of the NCAM gene family in zebrafish, designated as zNCAM, zOCAM, and zPCAM. Three molecules exhibit similar domain organization: an amino-terminal signal peptide, five immunoglobulin-like domains, two fibronectin type III-like domains, a transmembrane segment, and a carboxy-terminal cytoplasmic region. A novel molecule zPCAM is most closely related to zNCAM with 66% amino acid identity. Diversity in the extracellular region of zPCAM is generated by insertion of two different types of variable alternatively spliced exons. In situ hybridization analysis revealed that three molecules were specifically expressed by the central and peripheral nervous systems from early developmental stages in region-specific and cell-type-specific manners. For example, zPCAM showed a neuromere-specific segmental expression pattern, while zOCAM first appeared in specific clusters of secondary neurons in the forebrain. These results suggest that each member of the NCAM gene family plays distinct roles in the formation and maintenance of functional neuronal networks in the zebrafish nervous system.