EXPRESSION OF THE GENE FOR MAIN INTRINSIC POLYPEPTIDE (MIP) - SEPARATE SPATIAL DISTRIBUTIONS OF MIP AND BETA-CRYSTALLIN GENE TRANSCRIPTS IN RAT LENS DEVELOPMENT
EXPRESSION OF THE GENE FOR MAIN INTRINSIC POLYPEPTIDE (MIP) - SEPARATE SPATIAL DISTRIBUTIONS OF MIP AND BETA-CRYSTALLIN GENE TRANSCRIPTS IN RAT LENS DEVELOPMENT
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DOI：
10.1083/jcb.106.3.705
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发表时间：
1988-03-01
影响因子：
7.8
通讯作者：
REVEL, JP
中科院分区：
文献类型：
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作者：
YANCEY, SB;KOH, K;REVEL, JP
主要内在多肽（MIP）是存在于透镜纤维细胞膜中的主要蛋白质，并且是已知仅在透镜中表达的基因的产物。我们已经使用原位杂交和免疫荧光显微镜来表征该基因在大鼠发育过程中的表达。在透镜形态发生的进行性阶段，我们发现蛋白质的合成与MIP mRNA在致力于终末分化的细胞中的积累密切相关，首先在伸长的推定初级透镜纤维中，然后在次级纤维中，因为它们从前上皮细胞分化。转录本在次级纤维中围绕细胞核的基底细胞质中积累。我们已经将这种表达模式与胞质蛋白β的基因的表达模式进行了比较。晶状体蛋白β- A1/A3。与MIP mRNA所见的局部浓度形成鲜明对比，β- A1/A3转录物相对均匀地分布在整个细胞质中。MIP和晶状体蛋白基因在未分化的上皮细胞中似乎都没有转录活性，但是来自β-晶状体蛋白的转录物在未分化的上皮细胞中似乎没有转录活性。A1/A3基因在纤维细胞分化中的出现早于MIP基因。
the main intrinsic polypeptide (MIP) is the major protein present in the lens fiber cell membrane and is the product of a gene which, as far as is known, is expressed only in the lens. We have used in situ hybridization and immunofluorescence microscopy to characterize the expression of this gene during the course of development in the rat. At progressive stages of lens morphogenesis, we find that synthesis of the protein is closely tied to the accumulation of MIP mRNA in cells that are committed to terminal differentiation, first in the elongating presumptive primary lens fibers and later in the secondary fibers as they differentiate from the anterior epithelial cells. The transcripts accumulate in the basal cytoplasm which surrounds the cell nucleus in the secondary fibers. We have compared this pattern of expression with that of a gene for a cytoplasmic protein, .beta.-crystallin .beta.-A1/A3. In sharp contrast to the localized concentrations seen for the MIP mRNA, .beta.-A1/A3 transcripts are relatively uniformly distributed throughout the cytoplasm. Neither MIP nor crystallin gene appears to be transcriptionally active in the undifferentiated epithelial cell, but transcripts from the .beta.-A1/A3 gene appear earlier in fiber cell differentiation than do those from the gene for MIP.