Identification of genes preferentially expressed in testis and spermatogonial cells of Labeo rohita by subtractive and suppressive hybridization

摘要

Genetic information linked to the testicular development of Labeo rohita (rohu) could contribute towards understanding and improving breeding efficiency. A rohu testis-enriched cDNA library was generated by the subtractive and suppressive hybridization technique to identify differentially expressed genes. Two-hundred and forty differentially screened clones were sequenced and 77 non-redundant EST sequences with an average size of 0.5 kb were screened against GenBank entries. Homology analysis using the BLAST tool identified 35% as known genes, 40% as uncharacterized showing homology to unannotated ESTs or genomic sequences and 25% as unknown sequences. Four novel transcripts were identified in the reverse transcription-polymerase chain reaction expression profiles of a panel of gonadal tissues including spermatogonial and somatic tissues, three of which were transcribed exclusively in testicular spermatogonial cells, and one was expressed in both gonads. The POU50-domain-containing transcript was predominantly expressed in male germ cells. The novel transcripts could be utilized as biomarkers for fish spermatogonial cells for efficient isolation, characterization and propagation of differentiated and/or undifferentiated cells for studying the process of spermatogenesis.