Differential expression of four genes encoding molluscan insulin-related peptides in the central nervous system of the pond snail Lymnaea stagnalis
Differential expression of four genes encoding molluscan insulin-related peptides in the central nervous system of the pond snail Lymnaea stagnalis
复制标题
编码软体动物胰岛素相关肽的四个基因在池塘蜗牛 Lymnaea stagnalis 中枢神经系统中的差异表达
作者：
Irene Meester;M. Ramkema;J. Minnen;H. Boer
摘要在池塘蜗牛 Lymnaea stagnalis 中，生长调节系统由 (1) 约 200 个浅绿色神经内分泌细胞组成，分布在大脑神经节的四个簇中，以及 (2) 位于侧叶的成对冠层细胞。这些细胞表达编码软体动物胰岛素相关肽（MIP）的基因。先前已鉴定出 6 个 MIP 基因。其中四种（I、II、III 和 V）在浅绿色细胞和冠层细胞中表达。 MIP-VI 基因是假基因。在目前的原位杂交研究中，使用特异于MIP-I、-II、-III、-IV和-V转录本的寡核苷酸探针，用MIP-IV探针未获得信号，表明基因IV也是假基因。使用其他四个探针，可以区分出两种类型的浅绿色细胞。 A型细胞表达所有四种MIP基因，而B型细胞不（或仅微弱地）表达MIP-1基因。基因 III 在 B 型细胞中表达相对较强。基因 II 和 V 在两种细胞类型中均适度表达。 A型细胞主要位于簇的外围，而B型细胞则存在于簇的中心。冠层细胞类似于 A 型浅绿色细胞。 MIP-II 和 MIP-V 基因在冠层细胞中的表达水平较低。 MIP 基因的表达模式与抗 MIP-C 抗体的染色模式相关，该抗体已被提升为由 MIP-I、-II 和-V 共享的合成 C 片段。 A 型细胞被抗体染色的程度比 B 型细胞更强烈。
SummaryIn the pond snail Lymnaea stagnalis, the growth regulating system consists of (1) about 200 neuroendocrine light green cells, located in four clusters in the cerebral ganglia, and (2) the paired canopy cells, located in the lateral lobes. These cells express genes encoding the molluscan insulin-related peptides (MIPs). Six MIP genes have previously been identified. Four of these (I, II, III and V) are expressed in the light green cells and the canopy cells. The MIP-VI gene is a pseudogene. In the present in situ hybridization study, using oligonucleotide probes specific to the transcripts of MIP-I,-II,-III,-IV, and-V, no signal was obtained with the MIP-IV probe, indicating that gene IV is also a pseudogene. With the other four probes, two types of light green cells were distinguished. Type-A cells express all four MIP genes, whereas type-B cells do not (or only faintly) express the MIP-I gene. Gene III is relatively strongly expressed in type-B cells. Genes II and V are moderately expressed in both cell types. Type-A cells are mainly located in the periphery of the clusters, whereas type-B cells are present in the center. The canopy cell resembles type-A light green cells. The expression levels of the MIP-II and MIP-V genes are low in the canopy cell. The expression pattern of the MIP genes correlates with the staining pattern of the anti-MIP-C antibody, which has been raised to a synthetic C-fragment shared by MIP-I,-II and-V. Type-A cells stain more intensely with the antibody than type-B cells.