Different Hatching Strategies in Embryos of Two Species, Pacific Herring Clupea pallasii and Japanese Anchovy Engraulis japonicus, That Belong to the Same Order Clupeiformes, and Their Environmental Adaptation
Different Hatching Strategies in Embryos of Two Species, Pacific Herring Clupea pallasii and Japanese Anchovy Engraulis japonicus, That Belong to the Same Order Clupeiformes, and Their Environmental Adaptation
复制标题
DOI：
10.1002/jez.b.21247
复制
发表时间：
2009-03-15
影响因子：
2.2
通讯作者：
Yasumasu, Shigeki
中科院分区：
文献类型：
--
作者：
Kawaguchi, Mari;Fujita, Hideaki;Yasumasu, Shigeki
太平洋鲱鱼Clupea pallasii和日本鳀鱼Engraulis pallasii，属于同一目的鲱形目，产卵不同类型的卵：底层附着卵和浮游卵，分别。我们克隆了三个太平洋鲱鱼孵化酶的cDNA和五个日本鲱鱼。系统发育分析将其分为两组（A组和B组），它们均在两种鱼的枕部分化并迁移至头部边缘的孵化腺细胞（HGC）中特异表达。日本鱼的HGC在该位置停止迁移，而太平洋鲱鱼的HGC继续向背侧迁移，并广泛分布在整个头部区域。在进化过程中，HGC的迁移程序会发生变化，以适应不同的孵化时间。基因表达分析表明，太平洋鲱鱼胚胎合成大量的孵化酶相比，日本鲱鱼。太平洋鲱鱼胚胎的绒毛膜厚约为日本鲱鱼胚胎的7.5倍。因此，两个物种之间基因表达水平的差异与绒毛膜厚度的差异相关。这些结果表明，每种鱼的孵化系统适应其各自的孵化环境。最后，从每个基因组DNA中克隆孵化酶基因。B组基因的外显子-内含子结构基本保持了祖先基因的结构，而A组基因丢失了一个内含子。在日本凤尾鱼基因中发现了由于核苷酸插入和/或重复而导致的外显子-内含子结构的几种基因特异性变化。J. Exp. Zool.（Mol. Dev. Evol.）312 B：95-107，2009. (c)2008威利利斯公司
Pacific herring Clupea pallasii and Japanese anchovy Engraulis japonicus, which belong to the same order Clupeiformes, spawn different types of eggs: demersal adherent eggs and pelagic eggs, respectively. We cloned three cDNAs for Pacific herring hatching enzyme and five for Japanese anchovy. Each of them was divided into two groups (group A and B) by phylogenetic analysis, They were expressed specifically in hatching gland cells (HGCs), which differentiated from the pillow and migrated to the edge of the head in both species. HGCs of Japanese anchovy stopped migration at that place, whereas those of Pacific herring continued to migrate dorsally and distributed widely all over the head region. During evolution, the program for the HGC migration would be varied to adapt to different hatching timing. Analysis of the gene expression revealed that Pacific herring embryos synthesized a large amount of hatching enzyme when compared with Japanese anchovy. Chorion of Pacific herring embryo was about 7.5 times thicker than that of Japanese anchovy embryo. Thus, the difference in their gene expression levels between two species is correlated with the difference in the thickness of chorion. These results suggest that the hatching system of each fish adapted to its respective hatching environment. Finally, hatching enzyme genes were cloned from each genomic DNA. The exon-intron structure of group B genes basically conserved that of the ancestral gene, whereas group A genes lost one intron. Several gene-specific changes of the exon-intron structure owing to nucleotide insertion and/or duplication were found in Japanese anchovy genes. J. Exp. Zool. (Mol. Dev. Evol.) 312B:95-107, 2009. (c) 2008 Wiley-Liss, Inc.