Cai W, Cao W, Wu L, Exley G E, Waneck G L, Karger B L, Warner C M
Department of Biology, Northeastern University, Boston, MA 02115, USA.
Immunogenetics. 1996;45(2):97-107. doi: 10.1007/s002510050177.
The protein product of the mouse preimplantation embryo development (Ped) gene, which controls the rate of preimplantation embryonic cleavage division and subsequent embryo survival, is the Qa-2 antigen. This major histocompatibility complex (MHC) class I b protein is encoded by four genes, Q6, Q7, Q8, and Q9. The present study was undertaken to begin to elucidate which of the four Qa-2-encoding genes are responsible for the Ped gene phenotype in the C57BL/6 mouse (H2(b)). First, restriction maps of the four genes, using 25 restriction enzymes, were created. The RE maps confirmed that Q6 is similar to Q8 and Q7 is similar to Q9, but that the Q6/Q8 gene pair differs from the Q7/Q9 gene pair. The genomic DNA sequences of Q6 and Q8 were determined, as well as the DNA sequences of exons 4 - 8 of Q9, and the 5' regulatory regions of Q6, Q8, and Q9. This DNA sequence information, combined with the published DNA sequence information for the entire Q7 gene and exons 1 - 3 of Q9, allowed us to design primers for reverse transcription-polymerase chain reaction that could distinguish which of the four genes were transcribed in mouse lymphocytes and embryos. It was found that all four genes are transcribed in lymphocytes, but only Q7 and Q9 are transcribed in mouse embryos. Thus, both Q7 and Q9 are candidates for the genes responsible for the Ped gene phenotype.
小鼠着床前胚胎发育（Ped）基因的蛋白质产物是Qa - 2抗原，该基因控制着床前胚胎分裂的速率及随后胚胎的存活。这种主要组织相容性复合体（MHC）I类b蛋白由四个基因Q6、Q7、Q8和Q9编码。本研究旨在阐明在C57BL/6小鼠（H2(b)）中，四个编码Qa - 2的基因中哪一个负责Ped基因表型。首先，使用25种限制酶构建了这四个基因的限制酶图谱。限制酶图谱证实Q6与Q8相似，Q7与Q9相似，但Q6/Q8基因对与Q7/Q9基因对不同。测定了Q6和Q8的基因组DNA序列，以及Q9外显子4 - 8的DNA序列，还有Q6、Q8和Q9的5'调控区。这些DNA序列信息，结合已发表的整个Q7基因和Q9外显子1 - 3的DNA序列信息，使我们能够设计用于逆转录 - 聚合酶链反应的引物，以区分这四个基因中哪些在小鼠淋巴细胞和胚胎中被转录。结果发现所有四个基因在淋巴细胞中均被转录，但在小鼠胚胎中只有Q7和Q9被转录。因此，Q7和Q9都是负责Ped基因表型的基因候选者。
