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PubMed2026

Morphological changes and transcriptomic insights into skeletal development of embryos and larvae of the sea urchin Strongylocentrotus intermedius.

To explore morphological features and molecular dynamics underlying skeletogenesis in the sea urchin Strongylocentrotus intermedius, we conducted combined morphological observation and comparative transcriptome analyses across representative embryonic and larval developmental stages. Morphological results showed that triradiate spicules first emerged at the gastrula stage. The 8-arm pluteus stage was identified as a key phase for skeletal remodeling, during which new three-radiate crystals transformed into complex stereoscopic ossicles including tube feet, spines and test plates. Transcriptomic data indicated that most differentially expressed genes (DEGs) were downregulated from the blastula to gastrula. The altered expression of basal metabolic genes and extracellular matrix genes including Colp2α and calm may be correlated with the linear mineralization of early spicules, which potentially reflects an energy adjustment pattern in developing larvae. During the transition from 6-arm to 8-arm pluteus, expression changes of calmodulin-like, Colp2α and SISin18G001660 suggest potential associations with regional calcium deposition and modifications of skeletal matrix properties. This work systematically characterizes morphological traits and transcriptional dynamics of skeletogenesis in S. intermedius. Its early spiculogenesis follows the conserved developmental pattern of echinoderms, while massive formation of stereoscopic ossicles occurs at the 8-arm pluteus stage. Stage-specific transcriptional changes across key larval skeletogenic stages are uncovered, offering transcriptomic resources for functional verification of skeletal regulatory genes.

Animals↗
PubMed2026

L-glutamine supplementation improves porcine sperm quality and early embryo development during in vitro fertilization.

L-glutamine (Gln), as a key additive in porcine sperm capacitation medium and in vitro fertilization (IVF) systems, has been shown to significantly improve sperm motility and survival rates. However, its precise roles during porcine IVF and subsequent early embryonic development remain elusive. This study utilized an IVF model in pigs to investigate the effects of glutamine on sperm quality and embryonic development. We found that Gln supplementation during sperm treatment significantly improved sperm quality, as evidenced by reduced reactive oxygen species (ROS) production and early apoptosis, while enhancing calcium ion levels and endoplasmic reticulum activity. Supplementing glutamine during embryo culture reduced polyspermy rates, promoted zygotic genome activation (ZGA) and accumulation of 5-ethynyluridine (EU) and histone modifications (H3K4me3 and H3K27ac) at the two-cell and four-cell stages, increased blastocyst formation rates and total cell numbers, while simultaneously reducing DNA damage and early apoptosis during the blastocyst stage. In summary, these findings demonstrate that Gln enhances porcine IVF outcomes by improving sperm quality, reducing polyspermy, and facilitating early embryonic development, thereby providing a basis for optimizing culture systems.

Animals↗
PubMed2026

[Exploring the mechanism underlying the efficacy differences of "Tiaojing Cuyun Acupuncture"for premature ovarian failure based on vaginal microbiota structure].

OBJECTIVE: To observe the efficacy of "Tiaojing Cuyun Acupuncture" combined with hormone replacement therapy in the treatment of premature ovarian failure (POF), and to investigate differences in vaginal microbiota among patients with different therapeutic responses, thereby preliminarily exploring the mechanism underlying efficacy differences. METHODS: Ninety-eight patients with POF were randomly divided into an observation group (49 cases, 1 case was eliminated)and a control group (49 cases, 1 case dropped out). The control group was treated with hormone replacement therapy with Femoston, one tablet each time, once daily. On the basis of the control group, the observation group was additionally treated with "Tiaojing Cuyun Acupuncture". Acupoint group 1 included Baihui (GV20), Zhongwan (CV12), Guanyuan (CV4), and bilateral Tianshu (ST25), Zigong (EX-CA1), Dahe (KI12), Zusanli (ST36), Sanyinjiao (SP6), and Taichong (LR3). Acupoint group 2 included Baihui (GV20), bilateral Shenshu (BL23), Ciliao (BL32), and Taixi (KI3). The two acupoint groups were used alternately, beginning with acupoint group 1. Treatment was administered once every other day, three times per week.Both groups were treated for three menstrual cycles. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH),estradiol (E2), and anti-M &#xfc; llerian hormone (AMH) levels on days 3-5 of the menstrual cycle were measured before and after treatment in the two groups. Self-rating anxiety scale (SAS) scores were assessed before and after treatment, and clinical efficacy was evaluated in the two groups. Five effective patients (G0 subgroup) and five ineffective patients (G1 subgroup)were randomly selected from each group, and their vaginal microbiota structure was analyzed using 16S rRNA sequencing. RESULTS: After treatment, FSH levels in both groups were lower than those before treatment (P<0.05); SAS scores in both groups were lower than those before treatment (P<0.05), and the observation group had lower SAS score than the control group (P<0.05). The total effective rate was 77.1% (37/48) in the observation group, which was higher than 56.3% (27/48) in the control group (P<0.05). Vaginal microbiota analysis showed that at the phylum level, the relative abundance of Firmicutes in the G0 subgroup of the control group was higher than that in the G1 subgroup, while the relative abundances of Bacteroidetes, Actinobacteria and Proteobacteria were lowed in the G0 subgroup. In contrast, the observation group exhibited an opposite trend: the G0 subgroup had lower Firmicutes abundance but higher abundances of Actinobacteria, Bacteroidetes and Proteobacteria compared with the G1 subgroup. At the family and genus levels, Bifidobacterium was enriched in the G0 subgroups of both groups, whereas Lactobacillus predominated in the G1 subgroups. The G0 subgroup of the control group showed higher abundance of Gardnerella, while both Lactobacillus and Gardnerella were concurrently elevated in the G1 subgroup of the observation group. Additionally, in the observation group indicated that Clostridiales and Rikenellaceae were significantly more abundant in the G0 subgroup than in the G1 subgroup (P<0.05). CONCLUSION: The "Tiaojing Cuyun Acupuncture" combined with hormone replacement therapy is superior to hormone replacement therapy alone in improving anxiety. There are differences in vaginal microbiota structure among patients with different theraputic efficacy, suggesting that the vaginal microecological environment may be involved in the mechanism of treatment response in POF.

Humans↗
PubMed2026

Factors Associated With Accelerated Fracture Healing in Patients With Traumatic Brain Injury and Extremity Comminuted Fractures: A Retrospective Case-Control Study.

OBJECTIVE: Although traumatic brain injury (TBI) has been clinically associated with accelerated bone healing, the factors that determine which patients experience this phenomenon remain poorly defined, and previous findings are conflicting. This study aimed to investigate the clinical factors associated with accelerated fracture healing in patients with TBI combined with comminuted fractures of the limbs, so as to provide an evidence-based foundation for elucidating the clinical phenomenon of TBI-promoted fracture healing. METHODS: A retrospective case-control study design was employed. Patients between January 2020 and April 2024 with concurrent diagnoses of TBI and comminuted fractures were included. Based on radiographic findings and RUST/mRUST scores, patients were divided into an accelerated healing group (AHG) and a normal/delayed healing group (NDHG). Clinical data including demographics (age, sex, BMI), TBI characteristics (injury site, GCS score), admission laboratory indices (blood count, coagulation function, inflammatory markers), and fracture site/local soft tissue conditions, as well as functional outcomes assessed by the Short Musculoskeletal Function Assessment (SMFA) questionnaire at final follow-up were collected. Univariate analysis and multivariate logistic regression analysis were used to identify independent factors influencing accelerated fracture healing. Receiver operating characteristic (ROC) curves were plotted to evaluate their predictive value. RESULTS: A total of 119 patients were included, with 69 in the AHG and 50 in the NDHG. Significant differences were observed between the two groups in terms of age, BMI, GCS score, and platelet count (p&#x2009;<&#x2009;0.05). Univariate analysis showed that age, BMI, GCS score, red blood cell count, and platelet count were associated with accelerated fracture healing (p&#x2009;<&#x2009;0.20). Multivariate logistic regression analysis indicated that younger age (OR&#x2009;=&#x2009;0.875, 95% CI: 0.821-0.934) and lower GCS score (indicating more severe TBI; OR&#x2009;=&#x2009;0.490, 95% CI: 0.339-0.707) were independent predictors of accelerated fracture healing. ROC curve analysis showed that the area under the curve (AUC) for age and GCS score in predicting accelerated healing were 0.893 and 0.851, respectively. CONCLUSIONS: In patients with TBI combined with comminuted fractures, younger age and greater TBI severity (lower GCS score) are independent predictors of accelerated fracture healing. These findings assist clinicians in the early identification of patients with high healing potential to optimize treatment strategies, facilitate the early identification of high-risk patients, and provide clinical clues for further exploration of the molecular mechanisms underlying neurohumoral regulation of bone regeneration.

Humans↗
PubMed2026

Perinatal depression, maternal thyroid status and fetus/infant health and development: A systematic review.

BACKGROUND: Thyroid hormones are known to influence both maternal depression and child developmental outcomes, while maternal depression independently affects child outcomes. The potential interaction between thyroid dysfunction and depression in shaping child development remains insufficiently explored. The present study addresses such interplay. METHODS: Following PRISMA 2020 and JBI guidelines, three databases were searched through December 2025 for primary studies on maternal thyroid status, perinatal depression, and child development. Risk of bias (RoB) was assessed using validated tools. Due to clinical and methodological heterogeneity, data were synthesized narratively following SWiM guidelines. RESULTS: Eleven studies were included. Beyond independent risks for preterm birth and behavioral problems, limited evidence supports a synergistic model, while most studies likely reflect the simple co-occurrence of risks. Maternal thyroid peroxidase antibodies (TPO-Ab) were associated with child externalizing problems exclusively in the presence of clinical depression. High depressive symptoms also attenuated the cognitive benefits of prenatal iodine supplementation. Thyroid status appears to function as a risk moderator rather than a mediator. However, 50% of observational studies presented high RoB, primarily due to participant attrition. CONCLUSION: Findings are still scarce to support a synergistic risk model where specific maternal thyroid parameters (i.e. thyroid autoimmunity and iodine status) may moderate the impact of depressive symptoms on child development. Despite the high RoB in half of the studies, results highlight the need for integrated screening protocols. Simultaneously assessing mental health and thyroid status may optimize risk stratification for high-risk mother-infant dyads.

Female↗
PubMed2026

Heat stress in cereal crops: reproductive development and grain filling.

Increasingly frequent extreme heat events threaten cereal production and food security under a changing climate. The reproductive-to-grain formation continuum of cereals is particularly vulnerable to elevated temperatures, as heat stress disrupts developmental processes from inflorescence formation and fertilization to grain filling and quality establishment. These disruptions reduce reproductive success, impair yield formation, and compromise grain quality. A comprehensive understanding of the developmental, physiological, molecular, and genetic basis of cereal heat tolerance is therefore essential for developing climate-adapted crops. This review summarizes recent advances in understanding heat stress during cereal reproduction and grain filling across major cereal crops. We first discuss how heat stress affects sequential developmental processes, including inflorescence development, gametophyte development, flowering and pollination, fertilization, and grain filling. We then integrate emerging evidence on cross-cutting mechanisms that connect stage-specific heat responses, focusing on hormonal and redox homeostasis, carbohydrate metabolism and source-sink coordination, proteostasis and endomembrane organization, and genome stability and multilayered gene regulation. Finally, we summarize the genetic basis of cereal heat tolerance by highlighting genetic determinants, favorable alleles, and their potential applications in breeding. We further discuss current bottlenecks and future opportunities for breeding heat-tolerant cereals.

Cereals↗
PubMed2026

Genomic identification and functional characterization of the nuclear receptor gene family in relation to sex determination and gonad development in the Pacific oyster (Crassostrea gigas).

Nuclear receptors (NRs) are a large superfamily of transcription factors that control a wide range of physiological processes by modulating the expression of downstream target genes. Numerous studies have confirmed that NR family members play critical and conserved roles in sex determination and gonadal development across metazoans. However, in mollusks, systematic characterization of NRs and their potential functions in gonadal regulation remain largely unexplored. In this study, 46 NR gene family members in the Pacific oyster (Crassostrea gigas) were identified and assigned to eight subfamilies. All NR family members contain at least one of the two core domains (DNA-binding domain, DBD; ligand-binding domain, LBD), and conserved exon-intron structures were observed within the same subgroup, indicating their evolutionary conservation. Furthermore, expression profiling revealed high expression of CgNR2F, CgNR5A1-1, and CgNR0B1 in undifferentiated gonads, suggesting their potential involvement in sex determination. CgNR1A and CgNR2E5 were specifically expressed in female gonads and exhibited female-biased expression patterns, indicating a putative role in ovarian development. Moreover, CgNR3A and CgNR3B showed high expression levels during the undifferentiated stage and early male development stage, implying their possible participation in male gonadal development and gametogenesis. These results expand the understanding of the NR gene family in C. gigas and help elucidate the potential functions of NR genes in sex determination and gonadal development.

Animals↗
PubMed2026

The circadian clock proteins PRR modulate root hair development via the RHD6/RSL module in Arabidopsis.

Root hairs, derived from trichoblasts, are critical for plant growth and environmental adaptation. Although environmental cues are known to influence root hair development, how endogenous timing systems such as the circadian clock integrate into the core transcriptional network governing root hair formation remains unclear. Here, we show that the circadian clock-associated protein PSEUDO-RESPONSE REGULATOR5 (PRR5) physically interacts with ROOT HAIR DEFECTIVE6 (RHD6) and RHD6 LIKE1 (RSL1), two basic helix-loop-helix transcription factors essential for root hair initiation. Genetic analyses suggest that PRR proteins contribute to root hair development under long-day conditions in Arabidopsis thaliana. Simultaneous disruption of PRR5, PRR7, and PRR9 results in defective root hairs, whereas PRR5 overexpression markedly increases root hair density and length. Transcriptomic and RT-qPCR analyses reveal that PRRs enhance the expression of RHD6, RSL1, and multiple downstream root hair-responsive genes, while modulating their temporal expression patterns. Furthermore, PRR5-mediated root hair promotion requires RHD6/RSL1, and PRR proteins enhance RHD6-dependent activation of the RSL4 promoter. PRRs also contribute to root hair development under phosphate-deficient and salt-stress conditions. Together, these findings establish a molecular framework in which PRR proteins regulate the RHD6/RSL network to coordinate root hair development and environmental responses.

Arabidopsis↗
PubMed2026

Genital surgery in children with differences of sex development (DSD): Strengths and concerns across diverging regulations in four European countries.

Differences of Sex Development (DSD) is a collective term for a heterogeneous group of rare congenital conditions characterized by atypical genetic, gonadal, or genital sexual development. The treatment of children with DSD, particularly the indications for and timing of surgical interventions, has been the subject of debate for decades. In recent years, social developments emphasizing children's rights to self-determination and bodily integrity, along with increasing societal acceptance of atypical sex characteristics, have encouraged a more cautious approach toward early genital surgery in children with DSD. In 2019, the European Parliament adopted a resolution urging Member States to enact legislation prohibiting elective genital surgical interventions on intersex infants and children. Since then, several countries have indeed implemented restrictive measures, including legal bans on early surgical procedures. In this paper, we share the experiences and insights gained in recent years as pediatric urologists working in four neighboring countries in multidisciplinary university centers specializing in DSD care and research. We focus on current approaches to the care of children with DSD, the evolution of relevant national policies over time, and the nature and impact of recently introduced restrictive regulations on early surgical interventions. By presenting perspectives from pediatric urologists across these four countries, we aim to contribute to ongoing discussions on the alignment and refinement of surgical treatment practices for children with DSD.

Humans↗
PubMed2026

Effects of rumen fluid transplantation on longissimus dorsi muscle development in Xizang sheep: An association analysis based on transcriptomic and serum metabolomic profiles.

This study aimed to investigate the effects of rumen fluid transplantation (RFT) on the growth and development of the longissimus dorsi muscle in female Xizang sheep. After RFT, muscle lightness differed significantly between the two groups, with the LDC group showing significantly higher lightness than the LDT group. In contrast, no significant differences were observed between groups in other muscle phenotypic traits, including drip loss, pH, cooking loss, shear force, redness, and yellowness. Antioxidant-related indices (SOD, GSH-PX, MDA, CAT, and T-AOC) also showed no significant differences between groups. Histological analysis revealed that muscle fiber length, width, and density were significantly greater in the experimental group than in the control group. Transcriptomic analysis identified 515 differentially expressed genes (DEGs), of which 419 were downregulated. KEGG analysis indicated that genes involved in muscle development-related pathways, such as cell adhesion and the PI3K-Akt signaling pathway, were predominantly downregulated. Key serum metabolites (L-kynurenine, IPA, allantoin, and propionylcarnitine) showed highly significant positive correlations with muscle fiber growth indices. In contrast, metabolites such as l-carnitine, acetylcarnitine, and citrulline were negatively correlated with muscle fiber growth, but positively correlated with the expression of muscle structure-related genes (COL11A1 and EFNA5) and with meat lightness. Overall, this study provides new insights into the potential molecular basis by which RFT influences muscle growth and development. However, the mechanisms by which RFT affects muscle development and meat quality-related traits remain unclear and warrant further investigation.

Animals↗
PubMed2026

Handle with care: packaging the oocyte epigenome for the next generation.

During oocyte growth, substantial epigenetic programming occurs to establish a distinctive epigenome including appropriately patterned DNA methylation and histone modifications. Oocyte epigenetic programming must be tightly spatiotemporally regulated to ensure that a wide variety of epigenetic modifiers correctly establish their respective modifications to mediate precise control of gene expression. Furthermore, epigenetic modifications in oocytes include canonical and non-canonical genomic imprints, which are transmitted through meiosis to offspring. Significantly, disruptions in oocyte epigenetic programming can cause aberrant developmental outcomes in the next generation mediated by altered imprinting. Polycomb repressive complex 2 is an important epigenetic modifier that establishes histone 3 lysine 27 trimethylation and non-canonical imprints during mouse oogenesis, which are important for normal offspring development. While it is widely recognised that altered oocyte epigenetic programming can disrupt offspring development, mechanisms controlling maternal epigenetic inheritance remain poorly understood. The possibility remains that non-canonical imprinting exists in humans, although this requires confirmation. This review discusses mouse and human oocyte epigenetic programming including interactions between various epigenetic modifiers and modifications that form the unique oocyte epigenome. Understanding how oocyte epigenetic programming is regulated will be crucial in discerning how changes to the oocyte epigenome can disrupt epigenetic memory and alter developmental outcomes in offspring.

Animals↗
PubMed2026

Pathogenic Variants in HEPACAM Alter Protein Localization and Interactome in Astrocytes of the Developing Mouse Cortex.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly, white matter edema, seizures, and motor and cognitive decline. Approximately 25% of MLC patients carry HEPACAM pathogenic variants, many of which are dominant missense variants causing remitting MLC Type 2b. HEPACAM encodes hepatic and glial cell adhesion molecule (hepaCAM), also known as GlialCAM, an astrocyte-enriched transmembrane protein with important roles in astrocyte territory establishment, gap junction coupling, branching organization, synaptic function, and development of the gliovascular unit. The molecular mechanisms through which pathogenic variants in HEPACAM alter hepaCAM protein function in&#xa0;vivo and facilitate MLC pathogenesis during brain development remain largely unknown. Here, we used new viral tools and proximity-based proteomics to examine how three different dominant pathogenic variants alter hepaCAM subcellular localization and protein interactome in astrocytes of the developing mouse cortex. We found dramatic changes in hepaCAM distribution throughout the astrocyte, which were common to all mutants tested. We also observed significant changes in protein interactome between wild type and mutant hepaCAM, including decreased association with previously described hepaCAM-interacting proteins Connexin 43 and CLC-2. Moreover, we identified the epilepsy-associate potassium channel KCNQ2 as a novel hepaCAM interaction partner and found reduced association between KCNQ2 and pathogenic variants. Collectively, our data provide new insights into hepaCAM protein function in astrocytes during brain development, reveal altered protein dynamics of pathogenic variants, and provide a new resource to explore the molecular underpinnings of MLC pathogenesis.

Animals↗
PubMed2026

New Horizons in the Development of Treatments for Substance Use Disorders.

Substance use disorders (SUDs) are a major public health problem in the United States and cause substantial morbidity and mortality. There are meaningful gaps in the available SUD treatment options, and the development of new therapies is urgently needed. While medications with U.S. Food and Drug Administration approval are available for alcohol, nicotine, and opioid use disorders, there are no approved pharmacotherapies for cannabis, cocaine, or methamphetamine use disorders. Behavioral treatments for SUDs have significant limitations in effectiveness and accessibility, and there is a need for the development of both new behavioral treatment options and new models of treatment delivery. The next generation of treatments for SUDs will likely come from a diverse set of interventions, including new drug classes, new technologies, and new methods of delivery.

Humans↗
PubMed2026

Pre-treatment polyfunctionality percentage (PFA) of CD8+ T cells is associated with development of immune-related adverse events (irAEs) in patients receiving immune checkpoint inhibitors (ICIs).

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have improved cancer survival, but immune-related adverse events (irAEs) occur frequently and can have devastating consequences. There are no validated methods to evaluate risk of irAEs prior to initiation of ICIs. MATERIALS AND METHODS: We conducted a pilot study evaluating the ability of blood-based, single-cell secretomic analysis to characterize irAEs. A total of 10 patients with thoracic malignancies who were scheduled to receive ICIs were enrolled. Each patient had a pre-ICI blood sample drawn as well as a sample at the time of irAE development or 12 weeks after ICI initiation, whichever came first. Utilizing IsoPlexis's IsoLight system, polyfunctionality percentages (PFAs) and strength indices (PSIs) were analyzed for CD4+ and CD8+ T cells. RESULTS: Five patients developed irAEs and 5 patients did not develop irAEs. Pre- and post-ICI CD8+ T cell PFA was significantly elevated in patients who developed irAEs compared with those who did not (p = 0.017 and p = 0.014, respectively). CONCLUSIONS: In this pilot study, pre-ICI CD8+ T cell PFA was associated with development of irAEs. While this is a pilot study, this is a first step toward developing a blood-based, streamlined assay to assess risk of irAEs prior to initiation of ICIs. Validation in larger cohorts is warranted.

Humans↗
PubMed2026

Estrone disrupts early reproductive development in juvenile male Siniperca chuatsi and is associated with brain and gonadal responses.

Whether estrone (E1)-associated disruption of early reproductive development in fish is accompanied by brain responses in addition to direct gonadal effects remains unclear. Here, juvenile Siniperca chuatsi, a non-model but economically important freshwater species, were exposed for 60 d to 0, 0.01, 0.1, and 1.0&#xa0;&#x3bc;g/L E1, spanning environmentally reported and elevated concentrations. By integrating waterborne concentration monitoring, histopathology, transcriptomics, and quantitative real-time PCR (qPCR) validation, we evaluated E1-associated changes in brain and gonadal tissues during early reproductive development. Waterborne E1 concentrations remained generally stable throughout the exposure period. At the highest tested concentration (1.0&#xa0;&#x3bc;g/L), E1 caused neuronal vacuolation and pyknosis in the hypothalamic region and induced distinct ovarian-like structures in the gonads of genetic males. In the brain, cyp19a1, crhr1, and adcy2a were significantly upregulated, whereas egr1 was significantly downregulated, indicating transcriptional changes in genes associated with local estrogen conversion, stress-response/cAMP signaling, and neuronal activity-related regulation within a broader injury/stress-response background. In the gonad, RNA-seq analysis showed significant downregulation of star2, hsd3b1, cyp17a1, and cyp11b and significant upregulation of hsd17b1, suggesting alterations in steroidogenesis-related gene expression at the transcriptomic level. qPCR analysis of selected gonadal candidate genes showed expression directions generally consistent with the RNA-seq results, and these molecular patterns were consistent with the feminized histological phenotype. Together, these results indicate that E1 can disrupt early reproductive development in juvenile S. chuatsi and support a cautious working model in which E1 exposure is accompanied by concurrent brain and gonadal responses. This study provides new evidence for understanding the toxic effects and ecological risk implications of natural estrogen E1 during early fish development.

Animals↗
PubMed2026

Comprehensive identification and evolutionary analysis of the Wnt gene family in bivalves: Insights into the larval development of the noble scallop Chlamys nobilis.

The Wnt gene family regulates fundamental developmental processes in metazoans, but its evolutionary composition and developmental deployment in bivalves remain largely unresolved. Here, we performed a comparative genomic analysis of Wnt genes in 19 bivalve species and examined developmental expression profiles in the noble scallop Chlamys nobilis, with Crassostrea gigas and Chlamys farreri used for cross-species comparison. A total of 235 Wnt genes were identified and assigned to 12 subfamilies. No reliable Wnt3 ortholog was detected in any analyzed bivalve, supporting the view that Wnt3 loss occurred early during lophotrochozoan evolution rather than representing a lineage-specific absence. Most Wnt proteins retained the conserved WNT domain, indicating strong structural conservation, whereas lineage-specific copy-number variation and gene loss were observed among species. C. farreri and C. gigas each retained 12 Wnt genes and lacked Wnt3, whereas C. nobilis lacked Wnt3, Wnt7, and Wnt16. Developmental transcriptome analysis and RT-qPCR revealed clear stage-specific expression patterns. In C. gigas, Wnt2/10/A were highly expressed during earlydevelopment and peaked around the D-shaped larval stage, while Wnt8 and Wnt11 showed distinct stage-specific peaks. By contrast, Wnt1/5/6/9 were more active during later larval development or juvenile formation. These results provide a comparative framework for bivalve Wnt evolution and identify candidate Wnt genes potentially involved in larval development and aquaculture-relevant developmental transitions.

Animals↗