Identification and characterization of cul-3b, a novel hominine CUL-3 transcript variant

摘要

Aim: To identify genes related to the human testis development by substrate hybridization technique. Methods: A human testis cDNA microarray was constructed and hybridized with probes prepared from human adult and fetal testes and spermatozoa mRNAs by reverse transcription reactions. The differentially expressed genes were sequenced.And a newly identified cullin-3 (CUL-3) transcript variant (designated cul-3b) was bio-informatically analyzed with an online GenBank database. Multi-tissue reverse transcription polymerase chain reaction (RT-PCR) was used to determine the tissue expression profile of cul-3b. Results: Cul-3b, a novel CUL-3 transcript variant, was identified. The expression level of cul-3b in adult testes was 3.79-fold higher than that in fetal ones. Cul-3b differed from cul-3(including NM_003590 and AY337761) in the opening reading frame and had three internal ribosomal entry sites (IRESes) in the 5'-UTR. These led to a 24 amino acid (aa) truncation at N-terminus of CUL-3b as compared with CUL-3 and a more motivated expression pattern of cul-3b under some strict circumstances. Additionally, cul-3b expressed ubiquitously in human tissues according to multi-tissue RT-PCR. Conclusion: Cul-3b is a novel transcript variant of CUL-3, which may be important not only for the development of human testis but also for that of other organs.