Schaefer L, Engman H, Miller J B
Myogenesis Research Laboratory, Massachusetts General Hospital, Charlestown 02129, USA.
Mamm Genome. 2000 Feb;11(2):104-10. doi: 10.1007/s003350010021.
In Drosophila, the erect wing (ewg) protein is required for proper development of the central nervous system and the indirect flight muscles. The fly ewg gene encodes a novel DNA-binding domain that is also found in four genes previously identified in sea urchin, chicken, zebrafish, and human. To identify mouse ewg homologs, we designed degenerate primers to the conserved DNA-binding domain. The RT-PCR product obtained from mRNA of the mouse muscle cell line C2C12 was used to screen cDNA libraries; a single gene was identified which encodes a predicted 503 amino acid protein. The mouse ewg homolog, termed Nrf1, was mapped to proximal Chr 6. By RT-PCR and Northern analysis, Nrf1 was expressed in all tissues examined, and Northern analysis on adult tissues revealed a complex banding pattern suggesting extensive alternative splicing. Nrf1 hybridized to mRNA transcripts at approximately 2.2 kb, 4.0 kb, 4.4 kb, and 5.0 kb, with additional tissue-specific transcripts at 1.5 kb in testis, 1.9 kb in lung, and 3.7 kb in skeletal muscle. In situ hybridization on whole-mount E9-10.5 embryos showed a broad pattern of expression, with the highest levels of expression in the central nervous system, somites, first branchial arch, optic vesicle, and otic vesicle.
在果蝇中，直立翅（ewg）蛋白对于中枢神经系统和间接飞行肌的正常发育是必需的。果蝇ewg基因编码一种新的DNA结合结构域，该结构域也存在于先前在海胆、鸡、斑马鱼和人类中鉴定出的四个基因中。为了鉴定小鼠ewg同源物，我们针对保守的DNA结合结构域设计了简并引物。从小鼠肌肉细胞系C2C12的mRNA获得的RT-PCR产物用于筛选cDNA文库；鉴定出一个单一基因，其编码一个预测的503个氨基酸的蛋白质。小鼠ewg同源物，称为Nrf1，定位于近端6号染色体。通过RT-PCR和Northern分析，Nrf1在所有检测的组织中均有表达，对成年组织的Northern分析显示出复杂的条带模式，表明存在广泛的可变剪接。Nrf1与大约2.2 kb、4.0 kb、4.4 kb和5.0 kb的mRNA转录本杂交，在睾丸中还有1.5 kb、肺中1.9 kb和骨骼肌中3.7 kb的额外组织特异性转录本。对E9 - 10.5期全胚原位杂交显示出广泛的表达模式，在中枢神经系统、体节、第一鳃弓、视泡和听泡中表达水平最高。
