Germ line development in fishes.
Germ line development in fishes.
复制标题
DOI：
10.1387/ijdb.10668983
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
A. K. Braat;J. Speksnijder;Danica Zivkovic
中科院分区：
文献类型：
--
作者：
A. K. Braat;J. Speksnijder;Danica Zivkovic
关于鱼类生殖细胞的经典研究涉及三个主要问题：胚胎起源、增殖以及胚胎和幼体发育过程中的迁移途径。直到最近，原始生殖细胞（PGCs）已被研究的一些鱼类仅使用形态标准。鉴定的果蝇vasa同源基因的斑马鱼，现在可以比较这些形态学数据与vasa的RNA表达模式在斑马鱼。硬骨鱼类原始生殖细胞可以通过其独特的形态与体细胞区分开来，最早在原肠胚形成期间，并且在大多数鱼类中，它们的数量在生殖前发育期间在10和30之间变化。在性腺外位置的PGCs中通常不观察到有丝分裂，而一旦在性腺嵴处，它们就有丝分裂活跃。在原肠胚形成过程中，PGCs似乎从上胚层转移到下胚层，在体节发生过程中，它们被发现与最外周的卵黄合胞体层（YSL）有关。从外周YSL，他们迁移通过中间的中胚层到背中胚层，然后到背肠系膜，在那里他们建立了性腺原基与间充质细胞。Vasa RNA阳性细胞，斑马鱼的PGCs符合这些一般观察结果。有趣的是，经典的描述和实验数据，现在可以重新评估使用vasa作为鱼类生殖系的分子标记。斑马鱼遗传学的力量加上实验胚胎学的可能性，应该加速脊椎动物生殖系发育方面的研究，如PGC迁移，分裂和凋亡，以及（在）生育力。本综述总结了一些有关鱼类生殖系发育的经典数据，最近的数据在斑马鱼vasa表达，并比较这些研究结果，在适当的情况下，与其他模式生物。特别强调vasa基因表达作为一个潜在的通用生殖系标记，并提出了新的，斑马鱼的具体方法来研究脊椎动物生殖系的建议。
Classical work on germ cells in fishes has dealt with three main issues; their embryonic origin, the proliferation, and migration pathway during embryonic and larval development. Until recently, primordial germ cells (PGCs) have been studied in a number of fishes using morphological criteria only. The identification of the Drosophila vasa homolog gene of zebrafish now allows comparison of these morphological data with vasa RNA expression patterns in zebrafish. Teleost PGCs can be distinguished from somatic cells by their distinct morphology, at the earliest during gastrulation, and in most fishes their number varies between 10 and 30 during pregonial development. Mitosis is generally not observed in PGCs at extragonadal locations, whereas they are mitotically active once at the gonadal ridges. During gastrulation, PGCs appear to translocate from the epiblast to the hypoblast and during somitogenesis they are found associated with the most peripheral yolk syncitial layer (YSL). From the peripheral YSL they migrate through the median mesoderm into the dorsal mesoderm and then to the dorsal mesentery, where they establish the gonad primordia with mesenchymal cells. Vasa RNA positive cells, the PGCs of the zebrafish conform to these general observations. Interestingly, classical descriptive and experimental data can now be reevaluated using vasa as a molecular marker of the fish germ line. The power of zebrafish genetics together with possibilities of experimental embryology should accelerate research on aspects of vertebrate germ line development such as PGC migration, division and apoptosis, as well as (in) fertility. The present review summarizes some of the classical data on germ line development in fishes in relation to recent data on vasa expression in zebrafish and compares these findings, where appropriate, with those in other model organisms. Special emphasis is placed on vasa gene expression as a potential universal germ line marker and suggestions are made for novel, zebrafish specific approaches to investigate the vertebrate germ line.