Isolation of the choanocyte in the fresh water sponge, Ephydatia fluviatilis and its lineage marker, Ef annexin
Isolation of the choanocyte in the fresh water sponge, Ephydatia fluviatilis and its lineage marker, Ef annexin
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DOI：
10.1111/j.1440-169x.2005.00800.x
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发表时间：
2005-05
期刊：
影响因子：
4.6
通讯作者：
N. Funayama;M. Nakatsukasa;Tetsutaro Hayashi;K. Agata
中科院分区：
文献类型：
--
作者：
N. Funayama;M. Nakatsukasa;Tetsutaro Hayashi;K. Agata
为了研究淡水海绵的细胞系统，我们分离了最突出的细胞类型--脊孔细胞的分子标记。用荧光珠喂养海绵后，通过荧光激活细胞分选(FACS)收集荧光标记的棘细胞。通过对脊孔细胞和原始细胞(干细胞)富含组分的蛋白质谱分析，鉴定了脊孔细胞特有的蛋白质。脊索细胞特有的蛋白质之一的部分氨基酸序列与海绵表达标签(EST)克隆和小鼠Annexin VII推导的氨基酸序列相匹配，这些EST克隆重叠并编码一种蛋白质，命名为EF Annexin，它包括四个Annexin结构域。整体原位杂交显示EFAnnin在7日龄海绵形成腔的脊孔细胞中有表达，提示EFAnnin可以作为脊孔细胞的标志物。在早期发育阶段，EF Annexin在大的单细胞和形成2-、4-和多个细胞团的细胞中均可检测到。这些结果表明，EF膜联蛋白最初表达于由脊孔细胞承诺的原始细胞，然后经历几次有丝分裂形成脊孔细胞室。这表明，单个脊孔细胞室实质上起源于单个原始细胞。
In order to investigate the cellular system of the freshwater sponge, Ephydatia fluviatilis, we isolated a molecular marker for the most prominent cell type, the choanocyte. After feeding sponge with fluorescent beads, fluorescent‐labeled choanocytes were collected by fluorescence activated cell sorting (FACS). By protein profiling choanocyte and archeocyte (stem cell)‐rich fractions, proteins characteristic of choanocyte were identified. The partial amino‐acid sequence of one of the proteins characteristic of choanocyte matches the deduced amino‐acid sequence of sponge expression tag (EST) clones and mouse annexin VII. These EST clones overlap and encode a protein, designated Ef annexin, which includes four annexin domains. Whole mount in situ hybridization shows Ef annexin expression in chamber‐forming choanocytes in 7‐day‐old sponge, leading us to conclude that Ef annexin can be used as a choanocyte marker. In the early development stage, Ef annexin expression can be detected in both large single cells, characteristic of archeocytes, and cells forming 2‐, 4‐ and multiple‐cell clusters. These results indicate that Ef annexin is initially expressed in the choanocyte‐committed archeocyte which then undergoes several mitotic cell divisions to form a choanocyte chamber. This suggests that the single choanocyte chamber essentially originates from a single archeocyte.