Ringuette M J, Sobieski D A, Chamow S M, Dean J
Proc Natl Acad Sci U S A. 1986 Jun;83(12):4341-5. doi: 10.1073/pnas.83.12.4341.
The mouse zona pellucida genes are expressed uniquely during oogenesis and are developmentally regulated in the absence of cell division. Little is known about the mechanisms that control the expression of these germ-line-specific genes that play crucial roles in early mammalian development. We have constructed a lambda gt11 cDNA library from ovarian poly(A)+ mRNA and have isolated clones coding for ZP-3, the mouse sperm receptor. The identity of the clones was confirmed by comparing their DNA sequence with an amino acid sequence obtained from an isolated ZP-3 peptide. The ZP-3 gene is transcribed as a 1.7-kilobase poly(A) mRNA that is detected exclusively in ovarian tissue. This germ-line-specific expression is reflected in the observed hypomethylation of the ZP-3 locus in ovarian but not liver or brain DNAs. The ZP-3 gene is otherwise identically organized in somatic and germ-line DNA where it appears to be present as a low-copy-number or single-copy gene. Despite the fact that the mouse sperm receptor demonstrates species specificity, the ZP-3 cDNA cross-hybridized with DNA from a variety of mammalian species, including rat, rabbit, dog, pig, cow, and human.
小鼠透明带基因仅在卵子发生过程中表达，且在无细胞分裂的情况下受到发育调控。对于控制这些在早期哺乳动物发育中起关键作用的种系特异性基因表达的机制，人们了解甚少。我们从卵巢多聚腺苷酸加尾（poly(A)+）mRNA构建了一个λgt11 cDNA文库，并分离出了编码小鼠精子受体ZP-3的克隆。通过将克隆的DNA序列与从分离的ZP-3肽获得的氨基酸序列进行比较，证实了克隆的身份。ZP-3基因转录为1.7千碱基的多聚腺苷酸mRNA，仅在卵巢组织中检测到。这种种系特异性表达反映在卵巢DNA中ZP-3基因座的低甲基化，而在肝脏或脑DNA中未观察到。在体细胞和种系DNA中，ZP-3基因的组织方式相同，它似乎以低拷贝数或单拷贝基因的形式存在。尽管小鼠精子受体表现出物种特异性，但ZP-3 cDNA与包括大鼠、兔子、狗、猪、牛和人类在内的多种哺乳动物的DNA发生交叉杂交。
