A.V. Zhirmunsky Institute of Marine Biology, National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia.
Far Eastern Federal University, Vladivostok, Russia.
PLoS One. 2018 Apr 12;13(4):e0195836. doi: 10.1371/journal.pone.0195836. eCollection 2018.
Echinoderms are capable of asexual reproduction by fission. An individual divides into parts due to changes in the strength of connective tissue of the body wall. The structure of connective tissue and the mechanisms of variations in its strength in echinoderms remain poorly studied. An analysis of transcriptomes of individuals during the process of fission provides a new opportunity to understand the mechanisms of connective tissue mutability. In the holothurian Cladolabes schmeltzii, we have found a rather complex organization of connective tissue. Transcripts of genes encoding a wide range of structural proteins of extracellular matrix, as well as various proteases and their inhibitors, have been discovered. All these molecules may constitute a part of the mechanism of connective tissue mutability. According to our data, the extracellular matrix of echinoderms is substantially distinguished from that of vertebrates by the lack of elastin, fibronectins, and tenascins. In case of fission, a large number of genes of transcription factors and components of different signaling pathways are expressed. Products of these genes are probably involved in regulation of asexual reproduction, connective tissue mutability, and preparation of tissues for subsequent regeneration. It has been shown that holothurian tensilins are a special group of tissue inhibitors of metalloproteinases, which has formed within the class Holothuroidea and is absent from other echinoderms. Our data can serve a basis for the further study of the mechanisms of extracellular matrix mutability, as well as the mechanisms responsible for asexual reproduction in echinoderms.
棘皮动物能够通过分裂进行无性繁殖。个体由于体壁结缔组织强度的变化而分裂成几部分。结缔组织的结构及其强度变化的机制在棘皮动物中仍未得到充分研究。分析分裂过程中个体的转录组为理解结缔组织可变性的机制提供了新的机会。在海参科的 Cladolabes schmeltzii 中，我们发现了一种相当复杂的结缔组织组织。发现了编码细胞外基质广泛结构蛋白以及各种蛋白酶及其抑制剂的基因的转录本。所有这些分子可能构成结缔组织可变性机制的一部分。根据我们的数据，棘皮动物的细胞外基质与脊椎动物的细胞外基质有很大的不同，缺乏弹性蛋白、纤连蛋白和 tenascin。在分裂过程中，大量转录因子和不同信号通路的组成部分的基因被表达。这些基因的产物可能参与调节无性繁殖、结缔组织可变性以及为随后的组织再生做准备。已经表明，海参 tenilins 是组织金属蛋白酶抑制剂的一个特殊群体，它在海参类中形成，而在其他棘皮动物中不存在。我们的数据可以为进一步研究细胞外基质可变性的机制以及棘皮动物无性繁殖的机制提供基础。
