The Caudal ParaHox gene is required for hindgut development in the mollusc Tritia (a.k.a. Ilyanassa)
The Caudal ParaHox gene is required for hindgut development in the mollusc Tritia (a.k.a. Ilyanassa)
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DOI：
10.1016/j.ydbio.2020.10.010
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发表时间：
2021-02-01
影响因子：
2.7
通讯作者：
Lambert, J. David
中科院分区：
文献类型：
--
作者：
Johnson, Adam B.;Lambert, J. David
尾侧同源盒基因在动物中被发现，通常与另外两个被称为ParaHox集群的同源盒基因有关。这些基因被认为是内胚层前-后轴的祖先，但尾轴的表达在现存群体中是多种多样的，经常出现在其他胚层。在这里，我们研究了尾部在软体动物Tritia (Ilyanassa) obsoleta胚胎中的作用。尾端表达最初是广泛的，然后逐渐受到限制，最后只在发育中的后肠（又名肠）中表达。使用morpholino寡核苷酸敲低ToCaudal特异性阻断后肠发育，这表明尽管ToCaudal最初广泛表达，但其功能作用是在后肠模式中。这是在螺旋体发育的动物中首次发现尾侧的功能特征，这是一种古老的胚胎发生模式，早在双边动物进化中就出现了。这些结果与ParaHox基因的祖先作用是内胚层的前后模式的假设是一致的。
Caudal homeobox genes are found across animals, typically linked to two other homeobox genes in what has been called the ParaHox cluster. These genes have been proposed to pattern the anterior-posterior axis of the endoderm ancestrally, but the expression of Caudal in extant groups is varied and often occurs in other germ layers. Here we examine the role of Caudal in the embryo of the mollusc Tritia (Ilyanassa) obsoleta. ToCaudal expression is initially broad, then becomes progressively restricted and is finally only in the developing hindgut (a.k.a. intestine). Knockdown of ToCaudal using morpholino oligonucleotides specifically blocks hindgut development, indicating that despite its initially broad expression, the functional role of ToCaudal is in hindgut patterning. This is the first functional characterization of Caudal in an animal with spiralian development, which is an ancient mode of embryogenesis that arose early in bilaterian animal evolution. These results are consistent with the hypothesis that the ancestral role of the ParaHox genes was anterior-posterior patterning of the endoderm.