Abstract Background Spermatogonial stem cells (SSCs) are critical for sustaining spermatogenesis. Even though several regulators of SSC have been identified in rodents, the regulatory mechanism of SSC in humans has yet to be discovered. Methods To explore the regulatory mechanisms of human SSCs, we analyzed publicly available human testicular single-cell sequencing data and found that Ankyrin repeat and SOCS box protein 9 (ASB9) is highly expressed in SSCs. We examined the expression localization of ASB9 using immunohistochemistry and overexpressed ASB9 in human SSC lines to explore its role in SSC proliferation and apoptosis. Meanwhile, we used immunoprecipitation to find the target protein of ASB9 and verified its functions. In addition, we examined the changes in the distribution of ASB9 in non-obstructive azoospermia (NOA) patients using Western blot and immunofluorescence. Results The results of uniform manifold approximation and projection (UMAP) clustering and pseudotime analysis showed that ASB9 was highly expressed in SSCs, and its expression gradually increased during development. The immunohistochemical and dual-color immunofluorescence results displayed that ASB9 was mainly expressed in nonproliferating SSCs. Overexpression of ASB9 in the SSC line revealed significant inhibition of cell proliferation and increased apoptosis. We predicted the target proteins of ASB9 and verified that hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), but not creatine kinase B-type (CKB), has a direct interaction with ASB9 in human SSC line using protein immunoprecipitation experiments. Subsequently, we re-expressed HIF1AN in ASB9 overexpressing cells and found that HIF1AN reversed the proliferative and apoptotic changes induced by ASB9 overexpression. In addition, we found that ABS9 was significantly downregulated in some NOA patients, implying a correlation between ASB9 dysregulation and impaired spermatogenesis. Conclusion ASB9 is predominantly expressed in human SSCs, it affects the proliferation and apoptotic process of the SSC line through HIF1AN, and its abnormal expression may be associated with NOA.

ABSTRACT A novel inclusion complexes nanofibrous membrane fluorescent sensor was prepared for recognizing F- via electrospinning and host–guest interaction. The host α-cyclodextrin on the surface of the electrospun nanofiber membrane is assembled into the guest azobenzene molecule which modified with F- fluorescent probe, and the formation of the inclusion complex is fixed on the surface of the nanofibrous membrane without external force, to prepare a novel surface controllable composite nanofiber membrane for F- detection. The inclusion complexes nanofibrous membrane exhibited favourable sensitivity and selectivity for F-. The introduction of F- would result in notable fluorescent decreasing of the membrane, but the other most common anions would not disturb the detection of F-. Moreover, this nanofibrous membrane was not only a fluorescent sensor for detecting F-, but also a good adsorbent for F- in solution.

Abstract Background: Knowledge of plant population structure facilitates conservation, management, and utilization of endangered plants. Research question: What is the current status of the natural populations of Tetracentron sinense in Leigong Mountain Nature Reserve (LMNR) and what future population development trends can be predicted? Studied species: Tetracentron sinense. Study site and period of research: T. sinense populations in LMNR in China in 2018. Methods: The population structure and quantity dynamics of four typical patches were studied using static life tables, survival curves, survival analyses, and time series analyses. Results: The age structures of the T. sinense populations were spindle-shaped, with few seedlings and saplings, and Deevey type II and III survival curves. The mortality rate (q x ) of each patch increased quickly, and then plateaued, finally increasing again. Survival rate (S x ) showed a contrary trend to q x . Trends in cumulative mortality rate (F (i) ), killing power (K x ), mortality density (f (ti) ), and hazard rate (λ (ti) ) with increasing age class were similar: increasing at a younger age, gradually stabilizing in middle age, and then increasing slightly in older age. The number of individuals in these T. sinense populations was predicted to decrease sharply in future, with younger individuals being seriously deficient. The results showed that the natural populations of T. sinense in the LMNR were relatively stable but were in an early stage of decline. Conclusions: The lack of younger individuals might reflect a bottleneck for regeneration of T. sinense populations, leading to a decline in population size.

Resumen Antecedentes: El conocimiento de la estructura poblacional de una planta facilita su conservación, manejo y utilización. Pregunta de investigación: ¿Cuál es el estado actual de las poblaciones naturales de Tetracentron sinense en la Reserva Natural de la Montaña Leigong (LMNR) y qué tendencias futuras de desarrollo de la población se pueden predecir? Especies estudiadas: Tetracentron sinense. Sitio y período de investigación: Poblaciones en LMNR, China, 2018. Métodos: Se usaron tablas de vida estáticas, curvas de supervivencia, análisis de supervivencia y análisis de series de tiempo para el análisis de la estructura poblacional y dinámica de parches. Resultados: Las estructuras de edad de las poblaciones de T. sinense mostraron forma de huso, con pocas plántulas y juveniles. Curvas de supervivencia Deevey tipo II y III. La tasa de mortalidad (q x ) de cada parche aumentó rápidamente, para estabilizarse y finalmente aumentar nuevamente. La tasa de supervivencia (S x ) mostró una tendencia contraria a q x . Las tendencias en las tasas de mortalidad acumulada (F (i) ), mortalidad (K x ), densidad de mortalidad (f (ti) ), y tasa de riesgo (λ (ti) ) fueron similares con el aumento de la clase de edad. Las poblaciones naturales de T. sinense en el LMNR eran relativamente estables, aunque en etapa temprana de disminución. El número de individuos en poblaciones de T. sinense disminuirá drásticamente en el futuro, donde los más jóvenes mostrarán serias deficiencias. Conclusiones: La ausencia de individuos más jóvenes podría reflejar un cuello de botella para la regeneración de las poblaciones de T. sinense, lo que lleva a una disminución en el tamaño de la población.

Background: Cyclophilin A (CypA), a receptor for the immunosuppressive agent cyclosporin A (CsA), is a cis-trans peptidyl-prolyl isomerase (PPIase) which accelerates the cis-trans isomerization of prolyl-peptide bonds and interacts with a variety of proteins to regulate their activities. Results: The full-length cDNA of crab Eriocheir sinensis CypA (EsCypA) was cloned by EST and RACE technique. The complete sequence of EsCypA cDNA contained a 5' untranslated region (UTR) of 50 bp, a 3’ UTR of 233 bp with a polyA tail, and an open reading frame (ORF) of 495 bp encoding a polypeptide of 164 amino acids with the predicted molecular weight of 17.36 kDa. The deduced amino acid sequence of EsCypA contained two highly conserved signature sequences of peptidyl-prolyl cis-trans isomerase and a pro-isomerase domain. The mRNA transcripts of EsCypA were detectable in all the examined tissues, including haemocytes, gill, hepatopancreas, gonad, muscle and heart, with higher expression level in hepatopancreas and gonad. No significant difference in the relative mRNA expression level of EsCypA was observed during the whole course of bacteria challenge, whereas it was up-regulated during fungi challenge. The purified recombinant protein rEsCypA exhibited a significant PPIase activity and an antifungal activity. Conclusions: All these results indicated that it was a typical CypA member and potentially involved in the innate immune responses of crab.