Sperm mtDNA content and mtDNA4977bp deletion in normal and leukocytospermia men / 中华男科学杂志

<p><b>OBJECTIVE</b>To determine the sperm mtDNA content, mtDNA4977bp deletion and ROS in the seminal plasma of normal and leukocytospermia men, and to investigate the correlation of the changes of sperm mtDNA with the increase of leukocytes and reactive oxgygen species (ROS) in the seminal plasma.</p><p><b>METHODS</b>Seventy-eight semen samples from leukocytospermia patients and 31 from healthy donors were divided into 3 layers, supernatant fluid, 30% sperm and 80% sperm, by Percoll gradient centrifugation, their sperm mtDNA content and mtDNA4977bp deletion quantitatively analyzed by real-time PCR, and the level of ROS determined by flow cytometry.</p><p><b>RESULTS</b>The ROS in the seminal plasma and the sperm mtDNA contents of the three layers were all significantly higher in the leukocytospermia group than in the healthy control (P < 0.01). In the supernatant fluid and 80% layers, mtDNA4977bp deletion showed no obvious difference between the control and the leukocytospermia group, but was significantly higher in the 30% layer of the latter (P < 0.01). The ROS level was found positively correlated with the mtDNA content in the 30% (r = 0.347, P < 0.01) and the 80% layer (r = 0.456, P < 0.01), but not in the supernatant layer.</p><p><b>CONCLUSION</b>The increase of leukocytes and ROS may be one of the causes of the enhanced sperm mtDNA content, but has no significant impact on the mtDNA4977bp deletion.</p>

Identification and characterization of a spermatogenesis-related gene Ube1 in rat testis / 生理学报

A gene that could be potentially involved in spermatogenesis was identified and characterized by using suppression subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE) with total RNA from type A spermatogonia and pachytene spermatocytes of rat. This gene consists of 3 433 base pairs (bp) with a complete open reading frame (ORF) of 3 171 bp and encodes a putative protein containing 1057 amino acids. The nucleotide sequence displays a 93% identity to mouse ubiquitin-activating enzyme E1, Chr Y 1 (Ube1y1) and an 82% identity to human ubiquitin-activating enzyme E1 (UBE1). The putative protein of this gene contains an ubiquitin-activating enzyme signature 1 and an ubiquitin-activating enzyme active site, which are also existed in mouse ubiquitin-activating enzyme E1, human ubiquitin-activating enzyme E1 et al. So we named this gene as Rattus norvegicus ubiquitin-activating enzyme E1 (Ube1). The sequence of Ube1 was submitted to GenBank and the accession number is EF690356. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that Ube1 was specifically expressed in testis, while its expression was not detected in heart, brain, spleen, lung, liver, muscle, kidney and ovary. Comparison of the expression of Ube1 in different developmental stages of testis and Sertoli cells (real-time PCR) indicated that Ube1 was expressed more highly in spermatogonia than in spermatocytes, spermatids and Sertoli cells. In conclusion, Ube1 is a gene encoding rat ubiquitin-activating enzyme E1 and specifically expressed in testis, which might play a key role in ubiquitin system and influence spermatogenesis.

Screening differentially expressed genes in human bone marrow stromal cells at defined stage of differentiation / 生理学报

To screen differentially expressed genes involved in osteogenic differentiation of human bone marrow stromal cells (BMSCs) at defined stages, subtractive cDNA library was established by means of suppression subtractive hybridization. The BMSCs cultured for 12 and 21 d were used as driver and tester, respectively. A subtract library was successfully constructed and five positive clones were selected from the library. Sequencing analysis and homology comparison showed that the five clones differentially expressed in BMSCs cultured for 21 d were at least 90% homologous with the known genes in human GenBank. It was interestingly found that the osteogenic BMSCs cultured for 21 d differentially expressed decorin and Bax inhibitor 1. RT-PCR was performed to confirm the differentially expressed genes. The results showed that the expression of Bax inhibitor 1 was significantly higher in the cells of 21-day than that of 12-day, while the expression of decorin was only detected in the cells of 21-day.

Specific expression of beta-actin during spermatogenesis in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To screen the stage-specific expression proteins during rats spermatogenesis, and to investigate the beta-actin expression and localization in the tissues of rat testicular.</p><p><b>METHODS</b>Highly enriched type A spermatogonia, pachytene spermatocytes and round spermatids were isolated by STAPUT method (sedimentation velocity at unit gravity, with 2% - 4% BSA gradient in DMEM/F12 medium) respectively to get the total proteins. The difference of protein expression between the three kinds of cells was analyzed by two-dimensional electrophoresis. Then the distribution of beta-actin in rat testicular tissues was investigated using specific anti-beta-actin antibodies by immunohistochemical method.</p><p><b>RESULTS</b>beta-actin was identified as a stage-specific expression protein by two-dimensional electrophoresis. beta-actin protein was more strongly expressed in type A spermatogonia and pachytene spermatocytes, but not in round spermatids. The immunohistochemical results showed that beta-actin was mainly located in the cytoplasm of type A spermatogonia and pachytene spermatocytes and in the nuclei of nearly mature spermatids.</p><p><b>CONCLUSION</b>beta-actin protein is a stage-specific expressed protein and may play an important role in spermatogenesis.</p>