Brain-specific homeobox Bsx specifies identity of pineal gland between serially homologous photoreceptive organs in zebrafish
Brain-specific homeobox Bsx specifies identity of pineal gland between serially homologous photoreceptive organs in zebrafish
复制标题
DOI：
10.1038/s42003-019-0613-1
复制
发表时间：
2019-10-07
影响因子：
5.9
通讯作者：
Fukada, Yoshitaka
中科院分区：
文献类型：
--
作者：
Mano, Hiroaki;Asaoka, Yoichi;Fukada, Yoshitaka
在非哺乳动物物种中作为光感受器官的松果体是视网膜的一系列同源物。在这里，我们发现，脑特异性同源盒（Bsx）是一个关键的调节器赋予个体的松果体之间的两个系列同源的光感受器官在斑马鱼。Bsx基因敲除可使负责光感受的松果体特异性基因exroh的表达减少，从而损害松果体的发育，而它可诱导松果体中视网膜特异性基因rho的异位表达。Bsx显着反式激活exroh启动子与Otx 5相结合，但不与Crx，通过其绑定到不同亚型的PIRE，DNA顺式元件驱动Crx/Otx依赖的松果体特异性基因表达。这些结果表明，松果体光感受神经元的身份是由Bsx和Otx 5的组合编码决定的，前者赋予松果体在组织水平上的特异性，后者决定感光细胞在细胞水平上的特异性。
The pineal gland functioning as a photoreceptive organ in non-mammalian species is a serial homolog of the retina. Here we found that Brain-specific homeobox (Bsx) is a key regulator conferring individuality on the pineal gland between the two serially homologous photoreceptive organs in zebrafish. Bsx knock-down impaired the pineal development with reduced expression of exorh, the pineal-specific gene responsible for the photoreception, whereas it induced ectopic expression of rho, a retina-specific gene, in the pineal gland. Bsx remarkably transactivated the exorh promoter in combination with Otx5, but not with Crx, through its binding to distinct subtypes of PIRE, a DNA cis-element driving Crx/Otx-dependent pineal-specific gene expression. These results demonstrate that the identity of pineal photoreceptive neurons is determined by the combinatorial code of Bsx and Otx5, the former confers the pineal specificity at the tissue level and the latter determines the photoreceptor specificity at the cellular level.