Burfeind P, Hoyer-Fender S
Institute of Human Genetics, University of Göttingen, Germany.
Dev Biol. 1991 Nov;148(1):195-204. doi: 10.1016/0012-1606(91)90329-2.
We have isolated a cDNA from rat testis homologous to the Drosophila melanogaster gene mst(3)gl-9 by screening a rat testis cDNA library with mst(3)gl-9 and by direct PCR amplification of upstream sequences out of the cDNA library. Homologous genes are also expressed in testes of different mammalian species. In rat testis, two different transcripts are found. Evidences are presented which suggest that these two transcripts are alternative splicing products. As proved by Northern blot analysis of testis RNA prepared from rats of different ages and by in situ hybridization to rat testis tissue sections, the mRNAs are first transcribed in early spermatids. The longest open reading frame of the cDNA encodes a polypeptide of 244 amino acids which contains 16.4% cysteine, 9.9% proline, and 5.7% glycine and closely resembles the sizes and amino acid compositions of two major polypeptides isolated from outer dense fibers of rat spermatozoa. The COOH-terminal end consists mostly of the tripeptide motif Cys-Gly-Pro, the main motif in D. melanogaster mst(3)gl-9. It is suggested that the isolated rat cDNA encodes a polypeptide which is a protein component of the outer dense fibers of spermatozoa.
我们通过用果蝇基因mst(3)gl-9筛选大鼠睾丸cDNA文库以及直接从cDNA文库中PCR扩增上游序列，从大鼠睾丸中分离出了一个与果蝇黑腹果蝇基因mst(3)gl-9同源的cDNA。同源基因也在不同哺乳动物物种的睾丸中表达。在大鼠睾丸中，发现了两种不同的转录本。有证据表明这两种转录本是可变剪接产物。通过对不同年龄大鼠睾丸RNA的Northern印迹分析以及对大鼠睾丸组织切片的原位杂交证明，这些mRNA首先在早期精子细胞中转录。该cDNA最长的开放阅读框编码一个由244个氨基酸组成的多肽，其中含有16.4%的半胱氨酸、9.9%的脯氨酸和5.7%的甘氨酸，与从大鼠精子外致密纤维中分离出的两种主要多肽的大小和氨基酸组成非常相似。COOH末端主要由三肽基序Cys-Gly-Pro组成，这是果蝇黑腹果蝇mst(3)gl-9中的主要基序。有人认为，分离出的大鼠cDNA编码一种多肽，它是精子外致密纤维的一种蛋白质成分。
