Ultralow freezer for molecular and cellular biology research

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Testicular Leydig cells are the main testosterone-producing cells in the male. These cells are indispensable for the proper development of external male genitalia, sex accessory glands, increased muscle mass, as well as production of mature sperm. Leydig cell function is tightly controlled by the pituitary luteinizing hormone (LH). LH binds to its receptor located on the surface of Leydig cells thus triggering activation of the several intracellular signaling pathways (the main one involving cAMP) leading to increased gene expression and steroidogenesis. The various pathways activated by cAMP remain to be fully elucidated. Similarly, the transcription factors downstream of the various signaling pathways and their mechanisms of action remain poorly understood. Therefore, the goal of my research programme is to identify novel cAMP-activated pathways and the downstream molecular effectors and to determine their mechanism of action. I had originally proposed that the nuclear receptor NUR77 played an important role in LH-induced Leydig cell steroidogenesis. Consistent with my hypothesis, we have shown that NUR77 regulates expression of different steroidogenic genes. In addition, we found that NUR77 expression as well as its activity involve a novel cAMP-activated kinase not previously described in Leydig cells: CaMKI. My research programme involves complementary state-of-the-art molecular and cellular biology approaches to elucidate the roles played by NUR77 in LH-induced gonadal steroidogenesis. These approaches are also used to decipher the mechanisms of CaMKI activation by cAMP, which appears to involve intracellular Ca2+ concentrations. In addition to NUR77, we are also characterizing the roles of other transcription factors we have recently identified. Our various research protocols lead to the production of large quantities of precious biological materials (cell extracts, proteins, antibodies, DNA, RNA, media for steroid hormone measurements, etc). These samples must be preserved at low temperatures (-80C). Therefore, the requested -86C ultralow freezer is essential to maintain our productivity and achieve our goals.