Microbiota assembly during early ontogeny in teleost fish plays a central role in shaping immune maturation and establishing host-microbe homeostasis, yet the regulatory mechanisms driving microbial succession across key developmental windows remain poorly understood. In this study, Larimichthys crocea was used to delineate microbiota assembly dynamics and the impact of stochastic and deterministic processes. Results indicated that community assembly peaked at day 18 post-hatching (DPH18), coinciding with the highest neutral model fit (R 2=0.71) and migration rate (m=0.88). Alpha (α)-diversity exhibited a hump-shaped pattern, with Comamonas dominance inversely correlating with Vibrio at DPH18. Microbial source tracking indicated that host-associated taxa played a more prominent role than dietary or environmental sources. Transcriptomic profiling revealed pronounced immune modulation during early development. Pro-inflammatory signaling, including IL-17 pathway activation, was elevated prior to DPH18, while anti-inflammatory regulators, such as transforming growth factor beta 2 ( tgfb2), declined over time, consistent with a transient reduction in immune restraint. Immune constraints in dexamethasone-treated zebrafish produced intestinal barrier impairment and microbial dysbiosis, demonstrating functional consequences of compromised early immune regulation. Collectively, these patterns defined DPH3-DPH18 as a critical colonization window in L. crocea, during which reduced immune constraint facilitates niche establishment by early colonizers. This temporally restricted window optimizes microbial resilience and long-term resistance to dysbiosis, providing a mechanistic basis for early-life microbiota-directed strategies in teleost development.

Rodents play a pivotal role in the maintenance and transmission of zoonotic viruses. The Yili River Valley, one of the most biodiverse regions in Xinjiang, functions as a critical biogeographic corridor linking China with Central and Western Asia, and historically with Europe via the ancient Silk Road. Despite its significance, the viral landscape of this region remains largely unexplored. To elucidate the virological landscape of this understudied region, meta-transcriptomic sequencing was conducted on wild rodent samples collected between 2020 and 2023, encompassing multiple host species and tissue types (liver, lung, spleen, and intestine). Analysis identified 18 vertebrate-associated viral families, including several of known zoonotic or evolutionary relevance, such as Arteriviridae, Coronaviridae, Flaviviridae, Hantaviridae, Hepeviridae, Hepadnaviridae, and Picornaviridae. Remarkably, over 80% of the detected viruses represented putative novel species, highlighting the vast and previously undocumented viral diversity harbored by rodents in this region. Viral community composition exhibited clear host- and tissue-specific patterns. Critically, novel rodent-derived arteriviruses (RtArteVs) in Microtus obscurus were identified, exhibiting approximately 86% nucleotide identity with porcine reproductive and respiratory syndrome virus 1 (PRRSV1). Additionally, phylogenetic and recombination analyses support the hypothesis that PRRSV1 emerged through ancestral recombination among divergent RtArteVs, implicating rodents as the likely origin of this economically significant swine pathogen. These findings expand current understanding of rodent viromes in an important biodiversity hotspot, revealing a substantial yet largely uncharted viral diversity. Furthermore, this study underscores the critical need for continued surveillance of viral groups with potential for viral spillover to humans and domestic animals, including Arteriviridae, Flaviviridae, Hantaviridae, Hepeviridae, and Hepadnaviridae.

Gene loss represents a powerful driver of adaptive evolution. Cetaceans, which underwent a profound transition from terrestrial to fully aquatic life, provide an excellent model for investigating this process. Comparative genomic analysis of the cold-sensitive ion channel transient receptor potential ankyrin 1 ( TRPA1) revealed lineage-specific patterns of degeneration across cetaceans. In toothed whales, the ancestral lineage exhibited extensive exon loss within the TRPA1 locus, whereas baleen whales showed signatures consistent with markedly reduced or absent TRPA1 expression. These molecular alterations were inferred to disrupt or abolish TRPA1 protein function across cetaceans. Integration of these findings with established experimental evidence from human and murine TRPA1 studies supported several adaptive hypotheses for TRPA1 gene loss, including tolerance to abrupt thermal fluctuations, attenuation of nociceptive responses in aquatic environments, specialization of integumentary sensory systems, and the emergence of echolocation-associated sensory trade-offs in toothed whales. Collectively, these findings expand the gene loss repertoire of cetaceans and provide novel insights into the molecular underpinnings of secondary aquatic adaptation in mammals.

Embryo implantation requires coordinated interactions between the embryo and the maternal endometrium. Endometrial organoids (EOs) have emerged as promising in vitro models for studying this process. At present, however, mouse-derived EOs (mEOs) are predominantly composed of a single epithelial cell type and lack a functional luminal epithelium (LE), cellular diversity, and hormonally responsive architecture, limiting their capacity to recapitulate the dynamic receptive phase of the endometrium. In this study, a robust three-dimensional mouse endometrial assembloid model was established by co-culturing endometrial gland-like organoids (GLOs) with primary endometrial stromal cells (ESCs) under air-liquid interface (ALI) conditions. Optimization of the GLO culture was achieved by fine-tuning the concentrations of Wnt3a and R-Spondin1, while stromal viability and functionality were enhanced by supplementation with hydrocortisone, L-ascorbic acid, and ITS-X. Comparative analysis demonstrated that ALI conditions significantly enhanced epithelial proliferation, gland morphogenesis, and metabolic activity across both epithelial and stromal compartments. Notably, the resulting ALI-grown mouse endometrial assembloids (ALI-mEnAOs) developed a well-defined LE layer and recapitulated molecular and cellular features characteristic of both pre-receptive and receptive endometrial states in vivo. Compared to existing mEOs, analyses confirmed that ALI-mEnAOs closely mimic in vivo endometrial architecture, lineage composition, phase-specific gene expression signatures, and dynamic hormonal response. This model offers a physiologically relevant platform for mechanistic investigation of endometrial function and embryo implantation dynamics.

Heterozygous variants in ARR3, encoding cone arrestin, have emerged as a frequent cause of early-onset high myopia with a unique X-linked female-limited inheritance pattern. However, the mechanistic basis for this unusual anti-X-linked pattern is still unclear. Developmental expression profiling in mice demonstrated robust Arr3 expression in the retina from postnatal day 14 onward, with localization confined predominantly to outer segments of cones marked by red/green opsins, including a subset co-labeled with both red/green and blue opsins. Retinal flatmounts from Arr3 mutation knock-in mice and Arr3 knockout rats revealed a mosaic pattern of Arr3 expression in heterozygous individuals. Retinal single-cell RNA sequencing revealed significant shifts in cone subtype proportions in Arr3 +/- rats, with a marked reduction in M/S cones and a corresponding increase in S cones. Among differentially expressed genes, Pde6h was the only transcript altered in M/S cones across both Arr3 +/+ vs. Arr3 +/- and Arr3 -/0 vs. Arr3 +/- comparisons but not in Arr3 +/+ vs. Arr3 -/0 . These findings suggest that heterozygous Arr3 deficiency induces cone mosaicism that may mimic retinal defocus-like signals during phototransduction, potentially driving the development of high myopia under this distinctive inheritance model.

Body shape evolution in vertebrates frequently involves modifications in vertebral number or patterns of vertebral fusion, with distinct lineages displaying divergent trajectories. This study investigated the morphological and genetic basis of body shape variation between Hebao red carp (HB, Cyprinus carpio wuyuanensis) and Yellow River carp (YR, Cyprinus carpio haematopterus). Although both subspecies share an identical vertebral count (35), the compressed morphology of HB was attributable to skeletal anomalies, including vertebral shortening and fusion. Genome-wide association and population genetic analyses were performed on F1 and F2 hybrid cohorts to identify loci associated with this phenotype. A total of 231 selective sweep regions were detected across chromosomes A06, A08, A16, B05, and B06, with a prominent locus on chromosome A08 (15.99-16.39 Mb) strongly correlated with body shape traits. Transcriptomic analysis revealed haplotype-dependent expression of rflna within this interval, implicating rflna in axial skeletal patterning. Functional validation using CRISPR/Cas9-mediated knockout of rfln in zebrafish ( Danio rerio) induced vertebral malformations, including axial shortening, kyphosis, fusion, and a rounded abdominal profile. These results delineate the morphological and molecular framework governing axial remodeling in HB and highlight a conserved regulatory role for rflna in teleost skeletal development.

Arrhythmogenic cardiomyopathy (ACM) confers elevated risk of ventricular arrhythmias and sudden cardiac death, yet limitations in early lesion sampling and model development continue to hinder mechanistic and translational research. Clinical, pathological, and mutational profiles were examined in 24 individuals with ACM harboring PKP2 variants. Among these, a patient carrying the c.1132C>T mutation exhibited the earliest onset and presented both structural cardiac abnormalities and major adverse cardiovascular events. To facilitate disease modeling, the c.1147C>T variant-a previously reported pathogenic substitution located proximal to position c.1132 in PKP2-was selected to enhance the feasibility of generating a porcine model. The BE3 gene editing system was used to induce C>T mutation. Two single guide RNAs targeting the PKP2 gene were designed (sgRNA1 for c.1132C>T and sgRNA2 for c.1147C>T), yielding editing efficiencies of 42.9% and 25.9%, respectively. SgRNA1 was used to generate PKP2 +/- porcine fetal fibroblasts. A total of 14 cloned piglets were produced, including 11 viable and three stillborn PKP2 +/- individuals. By 24 months of age, PKP2 +/- pigs developed premature ventricular contractions and right ventricular dilatation. Histological analysis revealed adipocyte infiltration within the right ventricular wall, and electron microscopy demonstrated reduced desmosomal length and electron density consistent with desmosomal dysfunction. Transcriptomic profiling showed high expression of genes associated with lipid catabolic processes. This study established the first PKP2 +/- porcine model of ACM using BE3-mediated base editing, providing a valuable platform for elucidating early pathogenic mechanisms and evaluating therapeutic interventions.

Trichoplax adhaerens, one of the simplest multicellular organisms belonging to the phylum Placozoa, occupies a basal position within Metazoa and serves as a critical model for investigating early multicellular evolution. Despite its significance, the absence of functional genetic tools has limited research to comparative genomics, ultrastructural characterization, and behavioral observation. Developing methodologies such as transgenesis and gene editing would substantially expand experimental capabilities. However, the absence of sexual reproduction precludes the use of conventional approaches like single-cell microinjection. To overcome these limitations, the present study established a transgenic method for expressing exogenous genes in T. adhaerens. Systematic evaluation of multiple transfection techniques identified electroporation as the most effective strategy for inducing ectopic gene expression in this species. Electroporation parameters were optimized to maximize efficiency while minimizing cytotoxicity. Using this approach, robust expression of green fluorescent protein (GFP) was achieved using various promoters. Ectopic expression of the puromycin acetyltransferase ( PAC) gene conferred increased resistance to puromycin exposure, suggesting a potential strategy for generating stable transgenic lines in the future. This work introduces a reliable framework for ectopic gene expression in T. adhaerens, enabling molecular and functional analyses in one of the earliest-diverging metazoan lineages.