Analyses of genoarchitecture recently stimulated substantial revisions of anatomical models for the developing hypothalamus in mammalian and other vertebrate systems. The prosomeric model proposes the hypothalamus to be derived from the secondary prosencephalon, and to consist of alar and basal regions. The basal hypothalamus can further be subdivided into tuberal and mamillary regions, each with distinct subregions. Albeit being a widely used model system for neurodevelopmental studies, no detailed genoarchitectural maps exist for the zebrafish (Danio rerio) hypothalamus. Here, we compare expression domains of zebrafish genes, including arxa, shha, otpa, isl1, lhx5, nkx2.1, nkx2.2a, pax6, and dlx5a, the orthologs of which delimit specific subregions within the murine basal hypothalamus. We develop the highly conserved brain-specific homeobox (bsx) gene as a novel marker for genoarchitectural analysis of hypothalamic regions. Our comparison of gene expression patterns reveals that the genoarchitecture of the basal hypothalamus in zebrafish embryos 48 hours post fertilization is highly similar to mouse embryos at E13.5. We found the tuberal hypothalamus in zebrafish embryos to be relatively large and to comprise previously ill-defined regions around the posterior hypothalamic recess. The mamillary hypothalamus is smaller and concentrates to rather medial areas in proximity to the anterior end of the neural tube floor plate. Within the basal hypothalamus we identified longitudinal and transverse tuberal and mamillary subregions topologically equivalent to those previously described in other vertebrates. However, the hypothalamic diencephalic boundary region and the posterior tuberculum still provide a challenge. We applied the updated prosomeric model to the developing zebrafish hypothalamus to facilitate cross-species comparisons. Accordingly, we applied the mammalian nomenclature of hypothalamic organization to zebrafish and propose it to replace some controversial previous nomenclature.

中文翻译：

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斑马鱼胚胎中基底下丘脑的保守Genoarchitecture。

对基因结构的分析最近刺激了哺乳动物和其他脊椎动物系统中下丘脑发育的解剖模型的实质性修订。前体模型建议下丘脑来源于继发性前脑，并由阿拉尔区和基底区组成。下丘脑基底可进一步细分为管状和乳腺区域，每个区域都有不同的子区域。尽管是广泛用于神经发育研究的模型系统，但不存在斑马鱼下丘脑的详细基因构造图。在这里，我们比较了斑马鱼基因的表达域，包括arxa，shha，otpa，isl1，lhx5，nkx2.1，nkx2.2a，pax6和dlx5a，它们的直系同源物限定了鼠基底下丘脑内的特定子区域。我们开发高度保守的大脑特异性同源盒（bsx）基因，作为下丘脑区域基因建筑分析的新标记。我们对基因表达模式的比较表明，受精后48小时斑马鱼胚胎中基底下丘脑的基因结构与E13.5的小鼠胚胎高度相似。我们发现斑马鱼胚胎中的管状下丘脑相对较大，并包含下丘脑后凹周围未明确定义的区域。乳头下丘脑较小，集中在靠近神经管底板前端的相当内侧的区域。在基底下丘脑中，我们确定了纵向和横向的管状和乳腺亚区域，其拓扑结构与先前在其他脊椎动物中描述的区域相同。然而，下丘脑二脑边界区域和后结核仍是一个挑战。我们将更新的prosomeric模型应用于正在发展的斑马鱼下丘脑，以促进跨物种比较。因此，我们将下丘脑组织的哺乳动物命名法应用于斑马鱼，并提出用它来代替一些有争议的先前命名法。