Cloning of cDNA Encoding a Novel Mouse Actin-associated Protein Specifically Expressed in Lymphoid Tissues

A 200 bp novel gene fragment C55 was obtained from a mouse thymic stromal cell subtracted cDNA library by using suppression subtractive hybridization (SSH).GenBank database search and RT PCR amplification revealed a full length cDNA of 1 388 bp,which was confirmed by Northern blotting.The full length cDNA contains an open reading frame of 636 bp,encoding a predicted protein of 212 amino acids,which showed 62%～95% sequence identity with other arthropod and vertebrate SM22α.Northern blotting demonstrated differential expression of the mRNA transcript in the two thymic stromal cell lines.RT PCR analysis showed that the newly cloned gene is specifically expressed in lymphoid tissues.