Isolation and characterization of two T-box genes from sponges, the phylogenetically oldest metazoan taxon
Isolation and characterization of two T-box genes from sponges, the phylogenetically oldest metazoan taxon
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DOI：
10.1007/s00427-003-0345-5
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发表时间：
2003-09-01
影响因子：
2.4
通讯作者：
Müller, WEG
中科院分区：
文献类型：
--
作者：
Adell, T;Grebenjuk, VA;Müller, WEG
现在已经确定所有的后生动物门都起源于一个共同的祖先，假设的Urmetazoa。由于多孔动物在后生动物系统发育树中的基础地位，研究多孔动物的发育控制机制，可以为理解多细胞动物的起源和最初的身体结构是如何进化的提供线索。在这份报告中，我们描述了两个T-盒基因的分离和基因组特征的硅质海绵Suberites domuncula。系统发育分析将一个分类为Brachyury亚家族Sd-Bra，第二个分类为Tbx 2亚家族Sd-Tbx 2。Sd-Bra和Sd-Tbx 2序列和它们的内含子-外显子结构的分析表明它们在T-box家族的同源性中的基础位置，并且允许我们假设所有T-box基因的系统发育进化的模型。此外，我们报告了两种不同的产品的选择性剪接的Sd-Bra的存在下，并证明它们存在于不同的磷酸化和糖基化状态的海绵组织。分析了Sd-Bra在组织和3D-细胞聚集体（primmorfs）中的表达，表明Sd-Bra也可能在多孔藻形态发生中起作用。
It is now well established that all metazoan phyla derived from one common ancestor, the hypothetical Urmetazoa. Due to the basal position of Porifera (Demospongiae) in the phylogenetic tree of Metazoa, studies on the mechanisms controlling the development of these animals can provide clues on the understanding of the origin of multicellular animals and on how the first organization of the body plan evolved. In this report we describe the isolation and genomic characterization of two T-box genes from the siliceous sponge Suberites domuncula. The phylogenetic analysis classifies one into the subfamily of Brachyury, Sd-Bra, and the second into the Tbx2 subfamily, Sd-Tbx2. Analyses of the Sd-Bra and Sd-Tbx2 sequences and their intron-exon structures demonstrate their basal position in the phylogeny of the T-box family, and allows us to hypothesize a model of the phylogenetic evolution of all T-box genes. Furthermore, we report the presence of two different products of alternative splicing of Sd-Bra, and demonstrate that they exist in different phosphorylation and glycosylation states in the sponge tissue. Sd-Bra expression in tissue and 3D-cell aggregates (primmorphs) is analyzed, suggesting that Sd-Bra might also have a role in Porifera morphogenesis.