Behavior and Activity Patterns of the Critically Endangered Mangshan Pit Viper (Protobothrops mangshanensis) Determined Using Remote Monitoring.

This study focuses on understanding the behavior and activity patterns of the critically endangered Protobothrops mangshanensis in China in order to better provide scientific data for upcoming artificial breeding and propagation efforts. We conducted a long-term observation of 15 Mangshan pit vipers at different sites in Hunan Province during the summer and autumn of 2021. Our methods involved analyzing the influence of environmental factors such as temperature, relative humidity, and light condition on the snakes' day and night activity and behaviors. The results revealed that the wild behaviors of Protobothrops mangshanensis include resting, sunbathing, crawling, and exploring, with distinct rhythms in their diel behavior. The snakes' diel activity exhibits three peak periods which may be related to food activity and sunbathing. This study also highlights the complex interplay of environmental factors on the activity of Protobothrops mangshanensis. Relative humidity was identified as a critical factor accounting for the difference in activity between observation groups. There was little inter-individual variation among the 15 Protobothrops mangshanensis, even though these snakes used terrestrial and arboreal habitats under different environmental conditions. These findings enhance our understanding of Protobothrops mangshanensis behavior and provide a basis for effective conservation measures for this rare and critically endangered species.

Effects of BMP4/SMAD signaling pathway on mouse primordial follicle growth and survival via up-regulation of Sohlh2 and c-kit.

Bone morphogenetic protein 4 (BMP4) is essential for the development of primordial follicles, although its underlying mechanism remains largely unknown. By using cultured ovaries, the effects of BMP4 and the potential signal transduction pathways were investigated. Ovaries from 3-day-old female mouse pups were maintained in organ culture in the absence (control) or presence of BMP4 (100 ng/ml). At different culture time, the effects of BMP4 on primordial follicle growth and survival were assayed by follicle count and TUNEL labeling. The expression of phospho-SMAD1/5/8, Sohlh2, and c-kit were measured by immunohistochemistry, RT-PCR, and Western blotting. Immunohistochemistry was also performed to determine the expression pattern of BMP4, pSMAD1/5/8, Sohlh2, and c-kit in vivo during ovarian development. The results showed treatments of ovaries with BMP4 resulted in a significant (P < 0.05) increase on the primordial-to-primary follicle transition. The oocytes of primordial follicles treated with BMP4 were also less likely to undergo apoptosis. BMP4 enhanced the phosphorylation of SMAD1/5/8 and up-regulated the expression of Sohlh2 and c-kit in primordial follicles. During ovarian development in vivo, Sohlh2, and c-kit exhibited similar expression patterns to BMP4 and pSMAD1/5/8 in primordial follicles. The present studies suggest that BMP4/SMAD signaling pathway initiate primordial follicle growth and prevented oocyte apoptosis via up-regulation of Sohlh2 and c-kit.

WNT/ß-catenin-signaling pathway stimulates the proliferation of cultured adult human Sertoli cells via upregulation of C-myc expression.

The role of WNT/ß-catenin-signaling pathway is critical in mouse Sertoli cell maturation and tumorigenesis. This study aims to examine the effects of WNT/ß-catenin signaling on the cultured adult human Sertoli cells and the underlying molecular mechanisms. Glycogen synthase kinase 3ß (GSK-3ß) inhibitors, SB216763 and lithium chloride (LiCl), were used to activate WNT/ß-catenin-signaling pathway. 5-Bromo-2'-deoxyuridine (BrdU) incorporation assay and flow cytometry were used to analyze the proliferation and cell cycle of cultured human Sertoli cells, respectively. C-myc expression was accessed by immunofluorescence, real-time polymerase chain reaction and Western blot. The effects of c-myc on Sertoli cell proliferation were investigated by RNA interference technology and BrdU incorporation assay. The results showed activation of WNT/ß-catenin signaling stimulated human Sertoli cell proliferation. Obvious increases in c-myc messenger RNA and protein expression were observed after SB216763 and LiCl treatments. Knockdown of c-myc expression attenuated the ability of WNT/ß-catenin signaling to stimulate the proliferation of human Sertoli cells. WNT/ß-catenin signaling enhances human Sertoli cell proliferation via upregulation of c-myc expression.