Don J, Wolgemuth D J
Department of Genetics and Development, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Cell Growth Differ. 1992 Aug;3(8):495-505.
The gene designated meg1 (meiosis expressed gene) is a new mouse gene identified during a search for mammalian genes potentially involved in meiotic processes. Two classes of complementary DNAs were isolated from an adult mouse testis complementary DNA library, which shared the same 3' end including the entire putative coding region but differed in their 5' ends. Only one of these complementary DNA classes appeared to correspond to the very abundant 0.75-kilobase testicular transcript of meg1. Sequence analysis predicts a 10.8-kilodalton protein which is highly charged and lysine rich. It is also relatively rich in potential phosphoacceptor amino acids (approximately 17%), several of which are located in phosphorylation consensus sequences. The pattern of expression of meg1 was studied utilizing a combined Northern blot and in situ hybridization analysis. Of the adult tissues examined, meg1 transcripts were detected exclusively in testis. Analysis of mRNA from testes of two germ cell deficient mutant strains did not reveal significant levels of meg1 transcripts. Analysis of RNA from enriched populations of spermatogenic cells from adult testes and localization by in situ hybridization revealed that meg1 transcripts are most abundant in pachytene spermatocytes. These results suggest a role for meg1 during germ cell differentiation, possibly during meiotic prophase.
被命名为meg1（减数分裂表达基因）的基因是在寻找可能参与减数分裂过程的哺乳动物基因时鉴定出的一个新的小鼠基因。从成年小鼠睾丸互补DNA文库中分离出两类互补DNA，它们具有相同的3'末端，包括整个推定的编码区，但5'末端不同。这些互补DNA类别中只有一类似乎对应于meg1非常丰富的0.75千碱基睾丸转录本。序列分析预测出一种10.8千道尔顿的蛋白质，该蛋白质带电量高且富含赖氨酸。它还相对富含潜在的磷酸化受体氨基酸（约17%），其中几个位于磷酸化共有序列中。利用Northern印迹和原位杂交分析相结合的方法研究了meg1的表达模式。在所检测的成年组织中，仅在睾丸中检测到meg1转录本。对两种生殖细胞缺陷突变株睾丸的mRNA分析未发现meg1转录本的显著水平。对成年睾丸中富集的生精细胞群体的RNA分析以及原位杂交定位显示，meg1转录本在粗线期精母细胞中最为丰富。这些结果表明meg1在生殖细胞分化过程中发挥作用，可能在减数分裂前期。
