in-vitro-biochemical-assays-using-biotin-labels-to-study-protein

In Vitro Biochemical Assays using Biotin Labels to Study Protein-Nucleic Acid Interactions

Protein-nucleic acid interactions play important roles in biological processes such as transcription, recombination, and RNA metabolism. Experimental ...

Nanjing Medical University

Transcription factors of the Sox protein family contain a DNA-binding HMG box and are key regulators of progenitor cell fate. Here, we report that expression of Sox30 is restricted to meiotic spermatocytes and postmeiotic haploids.  mutant males are sterile owing to spermiogenic arrest at the early round spermatid stage. Specifically, in the absence of Sox30, proacrosomic vesicles fail to form a single acrosomal organelle, and spermatids arrest at step 2-3. Although most  mutant spermatocytes progress through meiosis, accumulation of diplotene spermatocytes indicates a delayed or impaired transition from meiotic to postmeiotic stages. Transcriptome analysis of isolated stage-specific spermatogenic cells reveals that Sox30 controls a core postmeiotic gene expression program that initiates as early as the late meiotic cell stage. ChIP-seq analysis shows that Sox30 binds to specific DNA sequences in mouse testes, and its genomic occupancy correlates positively with expression of many postmeiotic genes including , ,  and  These results define Sox30 as a crucial transcription factor that controls the transition from a late meiotic to a postmeiotic gene expression program and subsequent round spermatid development.

Sox30 initiates transcription of haploid genes during late meiosis and spermiogenesis in mouse testes.

Mechanistic target of rapamycin (mTOR) controls cell growth and metabolism in response to environmental and metabolic signals. Rapamycin robustly extends the lifespan in mammals and has clinical relevance in organ transplantation and cancer therapy but side effects include male infertility. Here, we report that chronic rapamycin treatment causes spermatogenic arrest in adult male mice due to defects in sex body formation and meiotic sex chromosome inactivation (MSCI). Many sex chromosome-linked genes were up-regulated in isolated pachytene spermatocytes from rapamycin-treated mice. RNA-Seq analysis also identified mRNAs encoding the core piRNA pathway components were decreased. Furthermore, rapamycin treatment was associated with a drastic reduction in pachytene piRNA populations. The inhibitory effects of rapamycin on spermatogenesis were partially reversible, with restoration of testis mass and sperm motility within 2 months of treatment cessation. Collectively, we have defined an essential role of mTOR in MSCI and identified a novel function as a regulator of small RNA homeostasis in male germ cells.

Wenxiu He

State Key Laboratory of Reproductive Medicine

Nanjing Medical University

In Vitro Biochemical Assays using Biotin Labels to Study Protein-Nucleic Acid Interactions

Wenxiu He

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}State Key Laboratory of Reproductive Medicine

Nanjing Medical University

In Vitro Biochemical Assays using Biotin Labels to Study Protein-Nucleic Acid Interactions

State Key Laboratory of Reproductive Medicine