Cloning and Characterization of a Novel Gene SRG-L Expressed in Late Stages of Mouse Spermatogenic Cells

Rui GUO, Peng-Peng
MA, Jing MA, Ye-Hua GE, She-Pu XUE, and Dai-Shu HAN*
( Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy
of Medical Sciences & Peking Union Medical College,
Beijing 100005, China )

Abstract A cDNA expressed
specifically in late stages of mouse spermatogenic cells during spermatogenesis
was cloned by using overlapping RT-PCR and RACE. The cDNA contained an open
reading frame (ORF) of 2625 base pairs that encoded an 874 amino acids protein.
Comparison analysis of amino acid
sequence showed 91% and 80% identity to a rat homologue XP-226242 and a monkey
homologue BAB63115 respectively. The expression of the mRNA was only observed
in pachytene spermatocytes, round, and elongating spermatids. We named this
gene as SRG-L (spermatogenesis related gene expressed in the late
stages of spermatogenic cells, GenBank accession No. AY352586). The tissue-specific
analysis showed that the SRG-L was highly expressed in spleen and testis.
The results suggested that SRG-L might play special roles during spermatogenesis,
particularly related to meiosis and spermiogenesis. Analysis of the amino acid
sequence showed there was a coiled-coil region near the N-terminal region and
rich phosphorylation sites, suggesting SRG-L might function as a transmembrane
protein mediating signal transduction. This study also demonstrated that gene
cloning by RT-PCR was applicable and convenient when its homologous gene was
known.

Key words spermatogenesis;
RT-PCR; RACE; gene cloning

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Received: March 8, 2004 Accepted:
April 15, 2004
This work was supported by a grant from the Major State Basic Research Development
Program of China (No. G1999055901).
*Corresponding author: Tel, 86-10-65296457; Fax, 86-10-65296466; Email, [email protected]