| 引用本文: | 滕镜如,刘新雨,谭素建,郇聘,刘保忠.3种典型贝壳形成基因在红条毛肤石鳖早中期担轮幼虫中的表达特征[J].海洋科学,2025,49(6):25-36. |
| |
|
| |
|
|
| 本文已被：浏览 255次 下载 198次 |
码上扫一扫！ |
|
|
| 3种典型贝壳形成基因在红条毛肤石鳖早中期担轮幼虫中的表达特征 |
|
滕镜如1,2, 刘新雨1,2, 谭素建1,2, 郇聘1,2, 刘保忠1,2
|
|
1.中国科学院海洋研究所 实验海洋生物学重点实验室, 山东 青岛 266000;2.中国科学院大学, 北京 100049
|
|
| 摘要: |
| 多板纲软体动物(石鳖)生有沿前后轴排列的8片贝壳,与其他类群差异很大。从演化的角度看,石鳖属于有刺亚门,其祖先与蛤蜊、螺等有壳亚门动物类群祖先在演化早期即分开,代表了另一条演化路径。对石鳖独特贝壳性状开展研究对于理解软体动物贝壳的起源和演化有重要的科学意义。本文以红条毛肤石鳖(Acanthochitona rubrolineata)为研究对象,筛选得到4个有壳亚门软体动物贝壳发育基因的同源基因,包括2个酪氨酸酶(tyrosinase)基因、信号通路分子bmp2/4基因和转录因子gata2/3基因(分别命名为AR-tyr1、AR-tyr2、AR-bmp2/4和AR-gata2/3),并分析了基因的表达模式与贝壳发育的相关性。首先预测候选基因编码蛋白的保守结构域并构建系统发育树,确定4个基因为tyrosinase、bmp2/4和gata2/3的直系同源基因,其包含该类基因典型的结构域。之后在石鳖早期贝壳发育关键阶段(24 hpf、36 hpf和48 hpf)的样品中进行整装原位杂交实验。结果显示,AR-tyr1和AR-tyr2在幼虫顶部、腹侧和担轮环处表达并且二者表达模式存在一定差异,AR-bmp2/4在顶部、腹侧、担轮环和背侧中胚层表达。这3个基因在贝壳发育区均没有明显的表达,与有壳亚门软体动物中特异性表达于贝壳发育区的表达模式截然不同。与此相对的,AR-gata2/3则在石鳖贝壳发育区几乎所有细胞中表达,虽然与贝壳形成相关,但与有壳亚门软体动物中局限在贝壳发育区外缘的表达模式非常不同。石鳖中这些重要贝壳形成基因的表达模式与在有壳亚门软体动物中存在显著的差异,提示两类动物贝壳早期发育机制存在重要的差别,为深入理解和探索不同软体动物类群贝壳的发育机制和同源性关系提供了支持。 |
| 关键词: 红条毛肤石鳖 贝壳发育 整装原位杂交 酪氨酸酶基因 bmp2/4 gata2/3 |
| DOI：10.11759/hykx20250226002 |
| 分类号:Q344 |
| 基金项目:崂山实验室科技创新项目课题(LSKJ202203002); 国家自然科学基金项目(42076123) |
|
| Expression characteristics of three shell-formation-associated genes in trochophore larvae of the chitona Acanthochitona rubrolineata |
|
TENG Jingru1,2, LIU Xinyu1,2, TAN Sujian1,2, HUAN Pin1,2, LIU Baozhong1,2
|
|
1.Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266000, China;2.University of Chinese Academy of Sciences, Beijing 100049, China
|
| Abstract: |
| Polyplacophora mollusks (chitons) possess eight shell plates arranged serially along the anterior–posterior axis, distinct from other mollusks. From an evolutionary perspective, chitons, whose ancestors diverged from Conchifera, such as clams and sea snails, at an early stage of evolution, are a group of Aculifera, representing a separate branch. Research on chiton shells is of great significance for understanding the origin and evolution of molluscan shells. In the present study, we screened four genes previously proven to be involved in conchiferan shell development from the chiton Acanthochitona rubrolineata—including two tyrosinase genes, the signaling molecule bmp2/4 gene, and the transcription factor gata2/3 gene (designated as AR-tyr1, AR-tyr2, AR-bmp2/4, and AR-gata2/3, respectively)—and analyzed the correlation between their expression and shell development. We first predicted the conserved domains encoded by these genes and constructed phylogenetic trees. The four genes were identified as the orthologs of tyrosinase, bmp2/4, and gata2/3, and the encoded peptides were predicted to contain conserved domains typically observed in the encoded proteins. We then performed whole mount in situ hybridization to analyze their expression patterns in the key stages of early shell development (24, 36, and 48 hpf). Slightly differing expression patterns of AR-tyr1 and AR-tyr2 were detected on the apical and ventral sides, as well as in the prototroch of larvae. AR-bmp2/4 was expressed in the apical and ventral sides, the prototroch, and the dorsal mesoderm of the larvae. These three genes were not conspicuously expressed in the shell field, contrary to their orthologs, a characteristically expressed in the shell fields of other conchiferans. In contrast, AR-gata2/3 was expressed in most shell field cells. Although associated with shell formation, the expression pattern of AR-gata2/3 varied markedly from that of its homologs in other conchiferans, whose expression is confined to the shell field edge. The dramatically different expression patterns of these vital shell-formation-associated genes between chitons and other conchiferans suggest considerable variations in the early shell development mechanisms in Aculifera and Conchifera. These findings enable further understanding of the relationship between molluscan shells and evolution. |
| Key words: Acanthochitona rubrolineata shell development whole mount in situ hybridization tyrosinase gene bmp2/4 gata2/3 |
|
|
|
|
|
|