Isolation of Ef silicatein and Ef lectin as molecular markers for sclerocytes and cells involved in innate immunity in the freshwater sponge Ephydatia fluviatilis
Isolation of Ef silicatein and Ef lectin as molecular markers for sclerocytes and cells involved in innate immunity in the freshwater sponge Ephydatia fluviatilis
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DOI：
10.2108/zsj.22.1113
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发表时间：
2005-10-01
影响因子：
0.9
通讯作者：
Agata, Kiyokazu
中科院分区：
文献类型：
--
作者：
Funayama, Noriko;Nakatsukasa, Mikiko;Agata, Kiyokazu
海绵动物(孔虫门)具有显著的再生和重建能力，在进化上代表了最古老的后生动物。为了研究海绵干细胞的分化，我们将重点放在淡水海绵的无性生殖系统上。在萌发过程中，数以千计的干细胞增殖和分化，形成功能齐全的海绵。作为干细胞(原始细胞)分化研究的第一步，我们分离了两种分化细胞类型的分子标记：形成毛刺的硬核细胞和参与先天免疫的细胞。硬化细胞系特异性EF硅酸盐与其他海绵硅酸盐有45%至62%的同源性。由于EF Silicatein的原位杂交可以特异地检测到可能附着于硬核细胞的原始细胞，以及具有未成熟或成熟毛刺的硬核细胞，因此涵盖了所有发育阶段，因此我们认为EF Silicatein是一个合适的硬核细胞谱系标记物。EF凝集素是参与先天免疫的细胞类型的标志，它与海绵Suberites domuncula半乳糖结合蛋白(SD GBP)和马蹄蟹Tachypleus tridentatus tachylectin1/lectinL6有59%至65%的同源性。由于scl、GBP和Tachylectin1已知能与细菌脂多糖结合并抑制细菌生长，EF凝集素可能具有类似的功能，并在参与防御入侵细菌的特殊类型的细胞中表达。EF凝集素的mRNA和蛋白在发育的早期不表达，但在发育的晚期检测到。因此，EF凝集素可能在分化和/或分化的细胞中特异表达。我们建议将EF凝集素作为淡水海绵细胞先天免疫的标志物。
Sponges (phylum Porifera) have remarkable regenerative and reconstitutive abilities and represent evolutionarily the oldest metazoans. To investigate sponge stem cell differentiation, we have focused on the asexual reproductive system in the freshwater sponge Ephydatia fluviatilis. During germination, thousands of stem cells proliferate and differentiate to form a fully functional sponge. As an initial step of our investigation of stem cell (archeocyte) differentiation, we isolated molecular markers for two differentiated cell types: spicule-making sclerocyte cells, and cells involved in innate immunity. Sclerocyte lineage-specific Ef silicatein shares 45% to 62% identity with other sponge silicateins. As in situ hybridization of Ef silicatein specifically detects archeocytes possibly committed to sclerocytes, as well as sclerocytes with an immature or mature spicule, therefore covering all the developmental stages, we conclude that Ef silicatein is a suitable sclerocyte lineage marker. Ef lectin, a marker for the cell type involved in innate immunity, shares 59% to 65% identity with the marine sponge Suberites domuncula galactose-binding protein (Sd GBP) and horseshoe crab Tachypleus tridentatus tachylectin1/lectinL6. Since Scl GBP and tachylectin1 are known to bind to bacterial lipopolysaccharides and inhibit the growth of bacteria, Ef lectin may have a similar function and be expressed in a specialized type of cell involved in defense against invading bacteria. Ef lectin mRNA and protein are not expressed in early stages of development, but are detected in late stages. Therefore, Ef lectin may be specifically expressed in differentiating and/or differentiated cells. We suggest Ef lectin as a marker for cells that assume innate immunity in freshwater sponges.