Expression of three spalt (sal) gene homologues in zebrafish embryos
Expression of three spalt (sal) gene homologues in zebrafish embryos
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DOI：
10.1007/s00427-002-0284-6
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发表时间：
2003-02-01
影响因子：
2.4
通讯作者：
Lardelli, M
中科院分区：
文献类型：
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作者：
Camp, E;Hope, R;Lardelli, M
果蝇区域特异性同源异型基因spalt（sal）的三个同源物已在斑马鱼中分离出来，sall 1a，sall 1b和sall 3。这些基因对已知的盐DNA序列的系统发育分析表明，斑马鱼sall 1a和sall 1b是orthopathic其他脊椎动物的sal-1基因和斑马鱼sall 3是orthopathic其他脊椎动物的sal-3基因，除了非洲爪蟾sall 3。系统发育重建表明，斑马鱼sall 1a和sall 1b是由一个基因复制事件发生之前的分歧，射线鳍和叶鳍鱼谱系。斑马鱼sal基因表达模式的分析表明，sall 1a和sall 3共享的表达结构域与直向和非直向脊椎动物sal基因。两者都在CNS的各个区域中表达，包括在初级运动神经元中。在CNS外，在耳囊（耳）、心脏和前肾管的离散区域中观察到sall 1a表达。这些分析表明，斑马鱼SAL基因和其他脊椎动物SAL基因之间的同源性并不意味着表达模式的等价性，因此，生物学功能并不完全保守。然而，我们认为，像其他脊椎动物的sal基因，斑马鱼的sal基因在神经发育中的作用。此外，斑马鱼胚胎的耳囊、心囊和前肾管中的斑马鱼sall 1a的表达可能与Sall 1缺陷小鼠和Townes-Brocks综合征中观察到的一些异常一致，Townes-Brocks综合征是一种由人类spalt基因SALL 1突变引起的人类疾病。
Three homologues of the Drosophila region-specific homeotic gene spalt (sal) have been isolated in zebrafish, sall1a, sall1b and sall3. Phylogenetic analysis of these genes against known sal DNA sequences showed zebrafish sall1a and sall1b to be orthologous to other vertebrate sal-1 genes and zebrafish sall3 to be orthologous to other vertebrate sal-3 genes, except Xenopus sall3. Phylogenetic reconstruction suggests that zebrafish sall1a and sall1b resulted from a gene duplication event occurring prior to the divergence of the ray-finned and lobe-finned fish lineages. Analysis of the expression pattern of the zebrafish sal genes shows that sall1a and sall3 share expression domains with both orthologous and non-orthologous vertebrate sal genes. Both are expressed in various regions of the CNS, including in primary motor neurons. Outside of the CNS, sall1a expression is observed in the otic vesicle (ear), heart and in a discrete region of the pronephric ducts. These analyses indicate that orthologies between zebrafish sal genes and other vertebrate sal genes do not imply equivalence of expression pattern and, therefore, that biological functions are not entirely conserved. However we suggest that, like other vertebrate sal genes, zebrafish sal genes have a role in neural development. Also, expression of zebrafish sall1a in the otic vesicle, heart sac and the pronephric ducts of zebrafish embryos is possibly consistent with some of the abnormalities seen in Sall1-deficient mice and in Townes-Brocks Syndrome, a human disorder which is caused by mutations in the human spalt gene SALL1.