Abstruct MGSAD023 (Mouse Gene Similar to AD023; Genbank accession AK150749) and its human compartment (AD023; Genbank accession AF225422) are new two genes with unknown functions. They were derived from high-throughput cDNA sequence analysis of the mouse genome project and Human Genome Project (HGP)，respec- tively. MGSAD023 shows 88.6% identity to AD023 (NCBI Blast)，and we decided to use MGSAD023 as a temple to explore the functions of these two compartment genes. With the NCBI Conserved Domain Database (CDD) and the gap program in GCG se- quence analysis software，we found that the amino acids of MGSAD023 showed 58.3% similarity and 4l.2% identity to eIF4G and also showed a good match to the middle domain of eIF4G. We determined the transcription pattern of MGSAD023. RT-PCR results showed that MGSAD023 was expressed in all of the tissues checked，including cerebellum， cerebra，liver，kidney，tongue，testis，heart and spleen，without any significant differ- ences.The results of In Situ Hybridization (ISH) showed that there was a very strong signal of mRNA of MGSAD023 on the seminiferous tubular basement membrane， where spermatogonia A and B are located. In silico exploration revealed homologous genes in various species，i ncluding chimpanzee，rat，mice，dog，zebra fish，fruit fly， xenopus，and cattle. These results hint that MGSAD023 is a conserved gene. It may act as a translation factor during cellular mitosis，especially in spermatogonia
