Human Testis-specific Transcription Of This Gene (prc-t) Cloning And Research,

Spermatogenesis, the fundamental function of adult testis, is a continuum of cellular differentiation in which three principal phases can be discerned: spermatogonia renewal and proliferation, meiosis and spermiogenesis. It is a complex process involving cell division, differentiation and interaction between cells in the microenvironment of the seminiferous tubule. Many genes specifically or highly expressed in testis tissue are involved in the process of spermatogenesis.Cloning of spermatogenesis related genes and further functional study are very important to the elucidation of molecular mechanism involving in meiosis and spermiogenesis process. It is also important to clinical diagnosis and treatment of male infertility and male molecular contraception. In order to isolate novel genes expressed in tissues, many approaches based on different display measurement, such as suppressed subtractive hybridization (SSH), differential display reversed transcripted PCR (DDRT-PCR) and cDNA microarray technology have been developed and improved. Compared with traditional hybridizing techniques, the use of cDNA microarray has many advantages, such as its large scale, high throughout, high efficiency and its objectivity.In order to clone genes associated with human testicular development and spermatogenesis, a human testis cDNA microarray was constructed andused to compare the genes differentially expressed between adult and fetal testes. A novel human testis-specific alternative splicing transcript was obtained, which encoded a subunit of the proteasome RP and was termed PRC-T(26S Proteasome Regulatory Component in Testis).The full length cDNA was 1316 bp with a complete ORF of 1056 bp encoding a putative protein of 351 amino acids. The nucleotide sequence of PRC-T cDNA was submitted to GenBank with the accession number AY359879. Comparison of DNA sequences showed that PRC-T gene was located on chromosome 3p21. It spanned 13427 bp of genomic DNA and was made up of 8 exons. Further sequence analysis revealed that PRC-T was a novel splicing variant of p44S10 gene family. The deduced PRC-T protein contained the 'RPN7' motif and 'PCI' domain, which was involved in the degradation of ubiquitinated proteins. The phylogenetic analysis indicated its high conservation during evolution. Expression profiles showed that PRC-T expressed specifically and highly in testis and mature sperm.Taken together, the results demonstrated that PRC-T gene was the only testis-specific isoform in p44S10 family found by now. It might encode a germ cell-specific proteasome regulatory particle subunit and play a potential role in spermatogenesis and normal sperm physiology. More study is needed to clarify the exact function of PRC-T gene.