摘要: Extracellular membrane proteins are crucial for mediating cell attachment, recognition, and signal transduction in the testicular microenvironment, particularly germline stem cells. Cadherin 18(CDH18), a type Ⅱ classical cadherin, is primarily expressed in the nervous and reproductive systems. Here, we investigated the expression of CDH18in neonatal porcine prospermatogonia(ProSGs) and murine spermatogonial stem cells(SSCs). Disruption of CDH18 expression did not adversely affect cell morphology, proliferation, self-renewal, or differentiation in cultured porcine ProSGs, but enhanced cell adhesion and prolonged cell maintenance. Transcriptomic analysis indicated that the down-regulation of CDH18 in ProSGs significantly up-regulated genes and signaling pathways associated with cell adhesion. To further elucidate the function of CDH18 in germ cells, Cdh18 knockout mice were generated, which exhibited normal testicular morphology,histology,andspermatogenesis.Transcriptomic analysis showed increased expression of genes associated with adhesion, consistent with the observations in porcine ProSGs. The interaction of CDH18with β-catenin and JAK2 in both porcine ProSGs and murine SSCs suggested an inhibitory effect on the canonical Wnt and JAK-STAT signaling pathways during CDH18 deficiency. Collectively, these findings highlight the crucial role of CDH18 in regulating cell adhesion in porcine ProSGs and mouse SSCs. Understanding this regulatory mechanism provides significant insights into the testicular niche.

摘要: The structural integrity of the sperm flagellum is essential for proper sperm function. Flagellar defects can result in male infertility, yet the precise mechanisms underlying this relationship are not fully understood. CCDC181, a coiledcoil domain-containing protein, is known to localize on sperm flagella and at the basal regions of motile cilia.Despite this knowledge, the specific functions of CCDC181in flagellum biogenesis remain unclear. In this study,Ccdc181 knockout mice were generated. The absence of CCDC181 led to defective sperm head shaping and flagellum formation. Furthermore, the Ccdc181 knockout mice exhibited extremely low sperm counts, grossly aberrant sperm morphologies, markedly diminished sperm motility, and typical multiple morphological abnormalities of the flagella(MMAF). Additionally, an interaction between CCDC181 and the MMAF-related protein LRRC46 was identified, with CCDC181 regulating the localization of LRRC46 within sperm flagella. These findings suggest that CCDC181 plays a crucial role in both manchette formation and sperm flagellum biogenesis.

摘要: The hypothalamic-pituitary-ovarian(HPO) axis represents a central neuroendocrine network essential for reproductive function. Despite its critical role, the intrinsic heterogeneity within the HPO axis across vertebrates and the complex intercellular interactions remain poorly defined. This study provides the first comprehensive,unbiased, cell type-specific molecular profiling of all three components of the HPO axis in adult Lohmann layers and Liangshan Yanying chickens. Within the hypothalamus,pituitary, and ovary, seven, 12, and 13 distinct cell types were identified, respectively. Results indicated that the pituitary adenylate cyclase activating polypeptide(PACAP), follicle-stimulating hormone(FSH), and prolactin(PRL) signaling pathways may modulate the synthesis and secretion of gonadotropin-releasing hormone(GnRH),FSH, and luteinizing hormone(LH) within the hypothalamus and pituitary. In the ovary, interactions between granulosa cells and oocytes involved the KIT,CD99, LIFR, FN1, and ANGPTL signaling pathways, which collectively regulate follicular maturation. The SEMA4signaling pathway emerged as a critical mediator across all three tissues of the HPO axis. Additionally, gene expression analysis revealed that relaxin 3(RLN3),gastrin-releasing peptide(GRP), and cocaine-and amphetamine regulated transcripts(CART, also known as CARTPT) may function as novel endocrine hormones,influencing the HPO axis through autocrine, paracrine, and endocrine pathways. Comparative analyses between Lohmann layers and Liangshan Yanying chickens demonstrated higher expression levels of GRP, RLN3,CARTPT, LHCGR, FSHR, and GRPR in the ovaries of Lohmann layers, potentially contributing to their superior reproductive performance. In conclusion, this study provides a detailed molecular characterization of the HPO axis, offering novel insights into the regulatory mechanisms underlying reproductive biology.

摘要: Zebrafish serve as a valuable model organism for studying germ cell biology and reproductive processes. The AB strain of zebrafish is proposed to exhibit a polygenic sex determination system, where most males initially develop juvenile ovaries before committing to male fate. In species with chromosomal sex determination, gonadal somatic cells are recognized as key determinants of germ cell fate.Notably, the loss of germ cells in zebrafish leads to masculinization, implying that germ cells harbor an intrinsic feminization signal. However, the specific signal triggering oogenesis in zebrafish remains unclear. In the present study, we identified foxl2l as an oocyte progenitor-specific gene essential for initiating oogenesis in germ cells.Results showed that foxl2l-knockout zebrafish bypassed the juvenile ovary stage and exclusively developed into fertile males. Further analysis revealed that loss of foxl2l hindered the initiation of oocyte-specific meiosis and prevented entry into oogenesis, leading to premature spermatogenesis during early gonadal development.Furthermore, while mutation of the pro-male gene dmrt1led to fertile female differentiation, simultaneous disruption of foxl2l in dmrt1 mutants completely blocked oogenesis,with a large proportion of germ cells arrested as germline stem cells, highlighting the crucial role of foxl2l in oogenesis. Overall, this study highlights the unique function of foxl2l as a germ cell-intrinsic gatekeeper of oogenesis in zebrafish.

摘要: Unraveling the phylogeographic histories of species remains a key endeavor for comprehending the evolutionary processes contributing to the rich biodiversity and high endemism found in East Asia. In this study, we explored the phylogeographic patterns and demographic histories of three endemic fishfly and dobsonfly species(Neochauliodes formosanus, Protohermes costalis, and Neoneuromus orientalis) belonging to the holometabolan order Megaloptera. These species, which share a broad and largely overlapping distribution, were analyzed using comprehensive mitogenomic data. Our findings revealed a consistent influence of vicariance on the population isolation of Neoc. formosanus and P. costalis between Hainan, Taiwan, and the East Asian mainland during the early Pleistocene, potentially hindering subsequent colonization of the later diverged Neon. orientalis to these islands. Additionally, we unveiled the dual function of the major mountain ranges in East Asia, serving both as barriers and conduits, in shaping the population structure of all three species. Notably, we demonstrated that these co-distributed species originated from Southwest,Southern, and eastern Central China, respectively, then subsequently migrated along multi-directional routes,leading to their sympatric distribution on the East Asian mainland. Furthermore, our results highlighted the significance of Pleistocene land bridges along the eastern coast of East Asia in facilitating the dispersal of mountaindwelling insects with low dispersal ability. Overall, this study provides novel insight into the synergistic impact of Pleistocene geological and climatic events in shaping the diversity and distribution of aquatic insects in East Asia.

摘要: Horseshoe bats (genus Rhinolophus,family Rhinolophidae) represent an important group within chiropteran phylogeny due to their distinctive traits,including constant high-frequency echolocation,rapid karyotype evolution,and unique immune system.Advances in evolutionary biology,supported by highquality reference genomes and comprehensive wholegenome data,have significantly enhanced our understanding of species origins,speciation mechanisms,adaptive evolutionary processes,and phenotypic diversity.However,genomic research and understanding of the evolutionary patterns of Rhinolophus are severely constrained by limited data,with only a single published genome of R.ferrumequinum currently available.In this study,we constructed a high-quality chromosome-level reference genome for the intermediate horseshoe bat (R.affinis).Comparative genomic analyses revealed potential genetic characteristics associated with virus tolerance in Rhinolophidae.Notably,we observed expansions in several immune-related gene families and identified various genes functionally associated with the SARS-Co V-2 signaling pathway,DNA repair,and apoptosis,which displayed signs of rapid evolution.In addition,we observed an expansion of the major histocompatibility complex class II (MHC-II) region and a higher copy number of the HLA-DQB2 gene in horseshoe bats compared to other chiropteran species.Based on whole-genome resequencing and population genomic analyses,we identified multiple candidate loci (e.g.,GLI3) associated with variations in echolocation call frequency across R.affinis subspecies.This research not only expands our understanding of the genetic characteristics of the Rhinolophus genus but also establishes a valuable foundation for future research.

摘要: In reptiles, such as the red-eared slider turtle(Trachemys scripta elegans), gonadal sex determination is highly dependent on the environmental temperature during embryonic stages. This complex process, which leads to differentiation into either testes or ovaries, is governed by the finely tuned expression of upstream genes, notably the testis-promoting gene Dmrt1 and the ovary-promoting gene Foxl2. Recent studies have identified epigenetic regulation as a crucial factor in testis development, with the H3K27me3 demethylase KDM6B being essential for Dmrt1 expression in T. s. elegans. However, whether KDM6B alone can induce testicular differentiation remains unclear. In this study, we found that overexpression of Kdm6b in T. s. elegans embryos induced the male development pathway, accompanied by a rapid increase in the gonadal expression of Dmrt1 at 31°C, a temperature typically resulting in female development. Notably, this sex reversal could be entirely rescued by Dmrt1 knockdown.These findings demonstrate that Kdm6b is sufficient for commitment to the male pathway, underscoring its role as a critical epigenetic regulator in the sex determination of the red-eared slider turtle.

摘要: The tree shrew(Tupaia belangeri) has long been proposed as a suitable alternative to non-human primates(NHPs) in biomedical and laboratory research due to its close evolutionary relationship with primates. In recent years,significant advances have facilitated tree shrew studies,including the determination of the tree shrew genome,genetic manipulation using spermatogonial stem cells, viral vector-mediated gene delivery, and mapping of the tree shrew brain atlas. However, the limited availability of tree shrews globally remains a substantial challenge in the field. Additionally, determining the key questions best answered using tree shrews constitutes another difficulty.Tree shrew models have historically been used to study hepatitis B virus(HBV) and hepatitis C virus(HCV)infection, myopia, and psychosocial stress-induced depression, with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases. Despite these efforts, the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research. This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model. We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies. The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models, meeting the increasing demands of life science and biomedical research.

摘要: SIL1, an endoplasmic reticulum(ER)-resident protein, is reported to play a protective role in Alzheimer's disease(AD). However, the effect of SIL1 on amyloid precursor protein(APP) processing remains unclear. In this study,the role of SIL1 in APP processing was explored both in vitro and in vivo. In the in vitro experiment, SIL1 was either overexpressed or knocked down in cells stably expressing the human Swedish mutant APP695. In the in vivo experiment, AAV-SIL1-EGFP or AAV-EGFP was microinjected into APP23/PS45 mice and their wild-type littermates. Western blotting(WB), immunohistochemistry,RNA sequencing(RNA-seq), and behavioral experiments were performed to evaluate the relevant parameters.Results indicated that SIL1 expression decreased in APP23/PS45 mice. Overexpression of SIL1 significantly decreased the protein levels of APP, presenilin-1(PS1),and C-terminal fragments(CTFs) of APP in vivo and in vitro. Conversely, knockdown of SIL1 increased the protein levels of APP, β-site APP cleavage enzyme 1(BACE1),PS1, and CTFs, as well as APP mRNA expression in2EB2 cells. Furthermore, SIL1 overexpression reduced the number of senile plaques in APP23/PS45 mice.Importantly, Y-maze and Morris Water maze tests demonstrated that SIL1 overexpression improved cognitive impairment in APP23/PS45 mice. These findings indicate that SIL1 improves cognitive impairment in APP23/PS45mice by inhibiting APP amyloidogenic processing and suggest that SIL1 is a potential therapeutic target for AD by modulating APP processing.

摘要: Emerging evidence indicates that sleep deprivation（SD） can lead to Alzheimer's disease（AD）-related pathological changes and cognitive decline. However, the underlying mechanisms remain obscure. In the present study, we identified the existence of a microbiota-gut-brain axis in cognitive deficits resulting from chronic SD and revealed a potential pathway by which gut microbiota affects cognitive functioning in chronic SD. Our findings demonstrated that chronic SD in mice not only led to cognitive decline but also induced gut microbiota dysbiosis, elevated NLRP3 inflammasome expression, GSK-3β activation, autophagy dysfunction, and tau hyperphosphorylation in the hippocampus. Colonization with the “SD microbiota” replicated the pathological and behavioral abnormalities observed in chronic sleep-deprived mice. Remarkably,both the deletion of NLRP3 in NLRP3^-/- mice and specific knockdown of NLRP3 in the hippocampus restored autophagic flux, suppressed tau hyperphosphorylation,and ameliorated cognitive deficits induced by chronic SD,while GSK-3β activity was not regulated by the NLRP3 inflammasome in chronic SD. Notably, deletion of NLRP3 reversed NLRP3 inflammasome activation, autophagy deficits, and tau hyperphosphorylation induced by GSK-3β activation in primary hippocampal neurons, suggesting that GSK-3β, as a regulator of NLRP3-mediated autophagy dysfunction, plays a significant role in promoting tau hyperphosphorylation. Thus, gut microbiota dysbiosis was identified as a contributor to chronic SD-induced tau pathology via NLRP3-mediated autophagy dysfunction,ultimately leading to cognitive deficits. Overall, these findings highlight GSK-3β as a regulator of NLRP3-mediated autophagy dysfunction, playing a critical role in promoting tau hyperphosphorylation.