Dynamic expression of multiple scavenger receptor cysteine-rich genes in coelomocytes of the purple sea urchin
Dynamic expression of multiple scavenger receptor cysteine-rich genes in coelomocytes of the purple sea urchin
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DOI：
10.1073/pnas.230096397
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发表时间：
2000-11-21
影响因子：
11.1
通讯作者：
Pancer, Z
中科院分区：
文献类型：
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作者：
Pancer, Z
体腔细胞，海胆假定的免疫细胞的异质性人口，被发现表达一套复杂的转录具有清道夫受体富含半胱氨酸（SRCR）重复。SRCR结构域定义了后生动物蛋白质超家族，其中许多涉及脊椎动物免疫系统的发育和调节。体腔细胞转录来自多基因家族的多个SRCR基因，所述多基因家族以特定于每个个体的特定模式编码估计数量为1，200个SRCR结构域。给定SRCR基因的转录水平可以从显著到不可检测的范围，然而所有测试的动物都具有编码这些基因的基因组位点。几个SRCR基因的分析揭示了对应于每种类型的多个位点。在一种SRCR类型的情况下，在133-kb的细菌人工染色体插入物内检测到至少三个基因的簇，并且在来自单个动物的三个基因组克隆的序列中鉴定出保守的和独特的区域。与重复样品的体腔细胞信息阵列杂交显示，许多sRCR基因的表达水平发生了实质性变化，1周内波动高达10倍，3个月内波动高达30倍。这份报告是第一次证明基因组和转录的复杂性，在无脊椎动物体腔细胞表达的分子。控制sRCR基因表达的机制和这个动态系统的功能意义有待阐明。
Coelomocytes, the heterogeneous population of sea urchin putative immune cells, were found to express a complex set of transcripts featuring scavenger receptor cysteine-rich (SRCR) repeats. SRCR domains define a metazoan superfamily of proteins, many of which are implicated in development and regulation of the immune system of vertebrates. Coelomocytes transcribe multiple SRCR genes from among a multigene family encoding an estimated number of 1,200 SRCR domains in specific patterns particular to each individual. Transcription levels for given SRCR genes may range from pronounced to undetectable, yet all tested animals harbor the genomic loci encoding these genes. Analysis of several SRCR genes revealed multiple loci corresponding to each type. In the case of one SRCR type, a cluster of at least three genes was detected within a 133-kb bacterial artificial chromosome insert, and conserved as well as unique regions were identified in sequences of three genomic clones derived from a single animal. Array hybridizations with repeated samples of coelomocyte messages revealed substantial alterations in levels of expression of many sRCR genes, with fluctuations of up to 10-fold in 1 week and up to 30-fold over a period of 3 months. This report is the first demonstration of genomic and transcriptional complexity in molecules expressed by invertebrate coelomocytes. The mechanisms controlling sRCR gene expression and the functional significance of this dynamic system await elucidation.