Low-intensity pulsed ultrasound activated the anti-tumor immunity by irradiating the spleen of mice in 4 T-1 breast cancer.

Tumor immunotherapy is booming around the world. However, strategies to activate the immune system and alleviate the immunosuppression still need to be refined. Here, we demonstrate for the first time that low-intensity pulsed ultrasound (LIPUS, spatial average time average intensity (Isata) is 200 mW/cm2, frequency is 0.3 MHz, repetition frequency is 1 kHz, and duty cycle is 20%) triggers the immune system and further reverses the immunosuppressive state in the mouse models of breast cancer by irradiating the spleen of mice. LIPUS inhibited tumor growth and extended survival in mice with 4 T-1 tumors. Further studies had previously shown that LIPUS enhanced the activation of CD4+ and CD8+ T cells in the spleen and led to significant changes in cytokines, as well as induced upregulation of mRNA levels involved in multiple immune regulatory pathways in the spleen. In addition, LIPUS promoted tumor-infiltrating lymphocyte accumulation and CD8+ T cell activation and improved the dynamics of cytokines/chemokines in the tumor microenvironment, resulting in a reversal of the immunosuppressive state of the tumor microenvironment. These results suggest a novel approach to activate the immune response by irradiating the spleen with LIPUS.

Long-term re-intervention after USgHIFU and prediction of NPVR in different ages of patients with uterine fibroids.

OBJECTIVE: Long-term re-intervention after ultrasound-guided high intensity focused ultrasound (USgHIFU) ablation was reported, and the prediction of non-perfusion volume ratio (NPVR) in differently aged patients with uterine fibroids (UFs) was explored. MATERIALS AND METHODS: Patients with UFs who underwent USgHIFU ablation from January 2012 to December 2019 were enrolled and divided into < 40-year-old and ≥ 40-year-old groups. Cox regression was used to analyze the influencing factors of re-intervention rate, and receiver operating characteristic (ROC) curve was used to analyze the correlation between NPVR and re-intervention rate. RESULTS: A total of 2141 patients were enrolled, and 1558 patients were successfully followed up. The 10-year cumulative re-intervention rate was 21.9%, and the < 40-year-old group had a significantly higher rate than the ≥ 40-year-old group (30.8% vs. 19.1%, p < 0.001). NPVR was an independent risk factor in both two groups. When the NPVR reached 80.5% in the < 40-year-old group and 75.5% in the ≥ 40-year-old group, the risk of long-term re-intervention was satisfactory. CONCLUSION: The long-term outcome of USgHIFU is promising. The re-intervention rate is related to NPVR in differently aged patients. Young patients need a high NPVR to reduce re-intervention risk.

Achieving NPVR ≥ 80% as technical success of high-intensity focused ultrasound ablation for uterine fibroids: a cohort study.

OBJECTIVE: To report the long-term re-intervention of patients with uterine fibroids after ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation and to analyse the influencing factors of re-intervention in patients in the NPVR ≥ 80% group. MATERIALS AND METHODS: Patients with a single uterine fibroid who underwent USgHIFU at our hospital from January 2012 to December 2019 were enrolled. The patients were divided into four groups according to different nonperfusion volume ratio (NPVR). Kaplan-Meier survival curve was used to analyse long-term re-intervention in different NPVR groups, and Cox regression was used to analyse the influencing factors of re-intervention in the NPVR ≥ 80% group. MAIN RESULTS: A total of 1,257 patients were enrolled, of whom 920 were successfully followed up. The median follow-up time was 88 months, and the median NPVR was 85.0%. The cumulative re-intervention rates at 1, 3, 5, 8 and 10 years after USgHIFU were 3.4%, 11.8%, 16.8%, 22.6% and 24.1%, respectively. The 10-year cumulative re-intervention rate was 37.3% in the NPVR < 70% group, 31.0% in the NPVR 70-79% group, 18.2% in the NPVR 80-89% group and 17.8% in the NPVR ≥ 90% group (P < 0.05). However, no difference was found between the group of NPVR 80-89% and the group of NPVR ≥ 90% (P = 0.499). Age of patients and signal intensity on T2-weighted imaging (T2WI) of tumours were found to be independent risk factors for long-term re-intervention in the NPVR ≥ 80% group. A younger age and greater signal intensity on T2W images corresponded to a greater risk of re-intervention. CONCLUSION: USgHIFU, an alternative treatment for uterine fibroids, has reliable long-term efficacy. NPVR ≥ 80% can be used as a sign of technical success, which can reduce re-intervention rates. However, an important step is to communicate with patients in combination with the age of patients and the signal intensity on T2WI of fibroids. TRIAL REGISTRATION: This retrospective study was approved by the ethics committee at our institution (Registration No. HF2023001; Date: 06/04/2023). The Chinese Clinical Trial Registry provided full approval for the study protocol (Registration No. CHiCTR2300074797; Date: 16/08/2023).

ROS-induced moderate autophagy of haemocytes confers resistance of Mercenaria mercenaria to air exposure stress.

Air exposure (AE) is a significant environmental stressor that can lead to desiccation, hypoxia, starvation, and disruption of cellular homeostasis in marine bivalves. Autophagy is a highly conserved catabolic pathway that facilitates the degradation of damaged macromolecules and organelles, thereby supporting cellular stress responses. To date, autophagy-mediated resistance mechanisms to AE stress remain largely elusive in bivalves. In this study, we performed a multi-tool approach to investigate the autophagy-related physiological regulation in hard clams (Mercenaria mercenaria) under different duration of AE (T = 0, 1, 5, 10, 20, 30 days). We observed that autophagy of haemocytes was significantly activated on day 5. However, autophagy activity began to significantly decline from day 10 to day 30. Autophagy was significantly inhibited after antioxidant treatment, indicating that reactive oxygen species (ROS) was an endogenous inducer of autophagy. A significant decline in the survival rate of hard clams was observed after injection of ammonium chloride or carbamazepine during AE stress, suggesting that moderate autophagy was conducive for clam survival under AE stress. We also observed DNA breaks and high levels of apoptosis in haemocytes on day 10. Activation of apoptosis lagged behind autophagy, and the relationship between autophagy and apoptosis might shift from antagonism to synergy with the duration of stress. This study provides novel insights into the stress resistance mechanisms in marine bivalves.

Factors influencing USgHIFU ablation for adenomyosis with NPVR ≥ 50.

OBJECTIVE: To investigate the influencing factors of ultrasound-guided HIFU (USgHIFU) ablation for adenomyosis with a non-perfused volume ratio (NPVR)≥50%. METHODS: A total of 299 patients with adenomyosis who underwent USgHIFU ablation were enrolled. Quantitative signal intensity (SI) analysis was performed on T2WI and dynamic enhancement type. The energy efficiency factor (EEF) was defined as the ultrasound energy delivered for ablating 1 mm3 of tissue. NPVR ≥ 50% was used as the criterion for technical success. Adverse effects and complications were recorded. Logistic regression analyses of variables were conducted to identify the factors affecting NPVR ≥ 50%. RESULTS: The median NPVR was 53.5% (34.7%). There were 159 cases in the NPVR ≥ 50% group and 140 cases in the NPVR < 50% group. The EEF in NPVR < 50.0% group was significantly higher than that in NPVR ≥ 50% group (p < 0.05). The incidence of intraoperative adverse effects and postoperative adverse events in the NPVR < 50% group were higher than those in the NPVR ≥ 50% group (p < 0.05 for both). Logistic regression analysis showed that abdominal wall thickness, SI difference on T2WI between adenomyosis and rectus abdominis, and enhancement type on T1WI were protective factors for NPVR ≥ 50% (p < 0.05), while the history of childbirth was an independent risk factor (p < 0.001). CONCLUSIONS: Compared with NPVR < 50%, NPVR ≥ 50% did not increase the intraprocedural and postprocedural adverse reactions. The possibility of NPVR ≥ 50% was higher in patients with thinner abdominal walls, showed slight enhancement of adenomyosis on T1WI, with a history of childbirth, or in whom the SI difference on T2WI between adenomyosis and rectus abdominis was more minor.

Comparison efficacy of ultrasound-guided HIFU for adenomyosis-associated dysmenorrhea with different signal intensity on T2-weighted MR imaging.

AIM: To compare the therapeutic efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) in the treatment of adenomyosis with different signal intensity (SI) on T2-weighted images (T2WI). METHODS: A total of 299 adenomyosis patients who underwent HIFU and completed a one-year follow-up were retrospectively reviewed. Based on the SI values of adenomyosis relative to myometrium and endometrium on T2WI MRI, the patients were classified into three groups: the hypointense adenomyosis (Hypo-AM) group, the isointense adenomyosis (Iso-AM) group, and the hyperintense adenomyosis (Hyper-AM) group. The non-perfused volume ratio (NPVr) and relief of dysmenorrhea were used to assess the therapeutic efficacy. Optimal cutpoints (CPs) of NPVr were determined using the postoperative dysmenorrhea score as an anchor. Logistic regression analysis was used to test the relationship between the NPVr and SI. RESULTS: The clinical effectiveness rate was significantly lower in the Hyper-AM group than in the Hypo-AM and Iso-AM groups (P < 0.05 for both). The NPVr in the Hypo-AM and Iso-AM groups were significantly higher than that in the Hyper-AM group (P < 0.05 for both). The optimal CP was 54.0% for NPVr. Logistic regression analysis showed that the SI on T2WI was an effect factor for NPVr (P < 0.05), and the probability of NPVr ≥54.0% decreased continuously as the SI of adenomyosis increased. CONCLUSIONS: The NPVr of 54.0% has a clinically significant impact on dysmenorrhea scores in patients. The efficiency of the Hypo-AM and Iso-AM was better than that of the Hyper-AM.

Tolerance and efficacy of HIFU ablation for uterine fibroids NPVR ≥ 90%: a nested case-control study.

OBJECTIVE: To investigate the tolerance and efficacy of HIFU ablation for uterine fibroids with a non-perfused volume ratio (NPVR) ≥ 90%. METHODS: A prospective cohort study of 2411 patients from 20 clinical centers was available. Contrast-enhanced MRI was used to assess the non-perfused volume ratio (NPVR). The International Society of Interventional Radiotherapy (SIR) complication grading system was used as the tolerance index. Uterine Fibroids-related Symptoms-Quality of Life (UFS-QoL) was used to evaluate the efficacy. RESULTS: A total of 1352 patients underwent USgHIFU ablation treatment enrolled, NPVR was median 91.9% (IQR, 81.4%,100.0%). There was 761 case (56.3%) in the NPVR ≥ 90% group in which 17.5% case experienced SIR-B abdominal pain, 591 cases (43.7%) in NPVR < 90% group in which 9.3% case had SIR-B abdominal pain. There were statistically differences in the improvement degree of UFS at 12 months among the four subgroups (NPVR < 70%, 70%-80%, 80%-90%, 90%-100%) (all p < 0.05). CONCLUSIONS: Patients with NPVR ≥ 90% had a higher incidence of SIR-B lower abdominal pain. NPVR was positively correlated with the degree of symptom relief at 12 months, and NPVR ≥ 90% was more likely to obtain better clinical symptom relief.

The hard clam genome reveals massive expansion and diversification of inhibitors of apoptosis in Bivalvia.

BACKGROUND: Inhibitors of apoptosis (IAPs) are critical regulators of programmed cell death that are essential for development, oncogenesis, and immune and stress responses. However, available knowledge regarding IAP is largely biased toward humans and model species, while the distribution, function, and evolutionary novelties of this gene family remain poorly understood in many taxa, including Mollusca, the second most speciose phylum of Metazoa. RESULTS: Here, we present a chromosome-level genome assembly of an economically significant bivalve, the hard clam Mercenaria mercenaria, which reveals an unexpected and dramatic expansion of the IAP gene family to 159 members, the largest IAP gene repertoire observed in any metazoan. Comparative genome analysis reveals that this massive expansion is characteristic of bivalves more generally. Reconstruction of the evolutionary history of molluscan IAP genes indicates that most originated in early metazoans and greatly expanded in Bivalvia through both lineage-specific tandem duplication and retroposition, with 37.1% of hard clam IAPs located on a single chromosome. The expanded IAPs have been subjected to frequent domain shuffling, which has in turn shaped their architectural diversity. Further, we observed that extant IAPs exhibit dynamic and orchestrated expression patterns among tissues and in response to different environmental stressors. CONCLUSIONS: Our results suggest that sophisticated regulation of apoptosis enabled by the massive expansion and diversification of IAPs has been crucial for the evolutionary success of hard clam and other molluscan lineages, allowing them to cope with local environmental stresses. This study broadens our understanding of IAP proteins and expression diversity and provides novel resources for studying molluscan biology and IAP function and evolution.

RNA-Seq analysis and WGCNA reveal dynamic molecular responses to air exposure in the hard clam Mercenaria mercenaria.

Intertidal bivalves are constantly exposed to air due to daily and seasonal tidal cycles. The hard clam Mercenaria mercenaria is an economically important bivalve species and often subjected to air exposure for more than 10 days during long-distance transportation. Hard clam exhibits remarkable tolerance to air exposure. In this study, we performed RNA sequencing on hemocytes of M. mercenaria exposed to air for 0, 1, 5, 10, 20 and 30 days. The overall and dynamic molecular responses of hard clams to air exposure were revealed by different transcriptomic analysis strategies. As a result, most cytochrome P450 1A and 3A, and monocarboxylate transporter family members were up-regulated during air exposure. Additionally, the dominant molecular process in response to 5-d, 10-d, 20-d and 30-d air exposure was refolding of misfolded proteins in endoplasmic reticulum, lysosome-mediated degradation of phospholipids, protein metabolism and reorganization of cytoskeleton, and activation of anti-apoptotic process, respectively. Our results facilitated comprehensive understanding of the tolerance mechanisms of intertidal bivalves to air exposure.

De novo assembly transcriptome analysis reveals the preliminary molecular mechanism of pigmentation in juveniles of the hard clam Mercenaria mercenaria.

Color plays a vital function in camouflage, sexual selection, immunity, and evolution. Mollusca possess vivid shell colors and pigmentation starts at the juvenile stage. The hard clam Mercenaria mercenaria is a widely cultivated bivalve of high economic value. To explore the molecular mechanism of pigmentation in juvenile clams, here, we performed RNA-Seq analysis on non-pigmented, white, and red M. mercenaria specimens. Clean reads were assembled into 358,285 transcripts and 149,234 unigenes, whose N50 lengths were 2107 bp and 1567 bp, respectively. Differentially expressed genes were identified and analyzed for KEGG enrichment. "Melanoma/Melanogenesis", "ABC transporters", and "Porphyrin and chlorophyll metabolism" pathways appeared to be associated with pigmentation. Pathways related to carotenoid metabolism seemed to also play a vital role in pigmentation in juveniles. Our results provide new insights into the formation of shell color in juvenile hard clams.

Case report: Antisynthetase syndrome with positive anti-PL7/SSA/RO52 antibodies.

Background: Antisynthetase syndrome (ASS) is a rare autoimmune disease characterized by the immune system attacking specific synthetase in the body. Due to the difficulty in clinical diagnosis, there is still a lack of effective treatment. Methods: We report a case of a 50-year-old man who presented with progressive, symmetric limb weakness, starting from the lower limbs and gradually affecting the upper limbs. He was admitted to the intensive care unit (ICU) for treatment due to recurrent fever and coma. When he was admitted to the ICU, his limbs were almost unable to move, and the levels of creatine phosphokinase and muscle glycogen were significantly elevated (2449 u/l and 1857 ng/ml). The electromyogram showed myogenic injury, and the anti-PL7 antibody, anti-SSA antibody, and anti-Ro52 antibody were positive. Pathological biopsy of the left biceps brachii showed striated muscle necrosis and macrophage infiltration. He was finally diagnosed with ASS and received treatment with methylprednisolone (subsequently changed to prednisone) and traditional Chinese medicine (Buzhongyiqi Decoction and Shenlingbaizhu powder). Results: After receiving 2 weeks of glucocorticoid and traditional Chinese medicine treatment, his muscle strength had basically recovered, reaching grade 5 in his limb muscles strength. During the 3-month follow-up period, his activity tolerance continued to improve. Conclusion: We present a case of severe anti-PL7 positive ASS with positive anti-SSA/Ro52 antibody. The disease was relieved by glucocorticoid and traditional Chinese medicine treatment. This provides an effective approach for managing ASS.

Children's bone age development is delayed with increasing altitude: a multicenter study.

OBJECTIVES: To investigate the bone age (BA) characteristics of children living at high-altitude regions and determine the impact of altitude on the development of BA. METHODS: From June 2014 to July 2022, 1,318 children with left hand-wrist radiographs were retrospectively enrolled from three different geographical altitudes (Beijing 43.5 m above sea level [asl], Lhasa 3650 m asl, and Nagqu 4500 m asl). The predicted age difference (PAD), defined as the difference between BA and chronologic age (CA), was considered the indicator for delayed or advanced growth. The PAD of children from the three regions in total and according to different age groups, genders, and ethnicities were compared. The linear regression model was used to assess the effect of altitude on PAD. RESULTS: A total of 1284 children (CA: 12.00 [6.45, 15.72] years; male: 837/1284, 65.2%) were included in the study with 407 from Beijing, 491 from Lhasa, and 386 from Nagqu. The PAD for Beijing, Lhasa, and Nagqu were 0.1 [-0.30, 0.65], -0.40 [-1.20, 0.27], and -1.42 [-2.32, -0.51] years, respectively. A linear regression analysis showed that altitude significantly contributed to PAD (compared to Beijing, Lhasa coefficient = -0.57, P < 0.001; Nagqu coefficient = -1.55, P < 0.001). CONCLUSIONS: High altitude might be an independent contributor to the delayed BA development of children. ADVANCES IN KNOWLEDGE: The impact of altitude on BA development was revealed for the first time, highlighting the necessity of considering the altitude of the area when evaluating BA development for children residing in high-altitude regions.

The safety and efficacy of myomectomy in the treatment of recurrent uterine fibroids after HIFU.

OBJECTIVE: To evaluate the safety and efficacy of myomectomy for recurrent uterine fibroids (UFs) after high-intensity focused ultrasound (HIFU) ablation. METHODS: This was a retrospective study. Patients who underwent abdominal myomectomy (AM) and laparoscopic myomectomy (LM) from January 2018 to December 2021 at the Three Gorges Hospital of Chongqing University were included. Among them, 73 had undergone prior HIFU ablation (Group 1), while 120 had not undergone HIFU (Group 2). Outcome measures included operating time, estimated blood loss (EBL), blood transfusion, postoperative activity times (PAT), duration of hospital stay (DOHS), and complications. RESULTS: The operating time was 90.0 min (70.5, 115.0) for Group 1 and 110.0 min (81.5, 130.0) for Group 2 (P < 0.05). During all AM pathways, there were no significant differences observed between the two groups in EBL, blood transfusion, PAT, DOHS, and complications; however, operating time was shorter in Group 1. The operating time, EBL, blood transfusion, PAT, DOHS, and complications were similar in both groups during LM pathway. During the follow-up 40 (range: 24-53) months, the rate of relief, recurrence, and reintervention in Groups 1 and 2 was 78.1% versus 74.1%, 14.6% versus 16.4%, and 3.7% versus 2.6%, respectively (P > 0.05). CONCLUSION: Myomectomy is a safe and effective surgical method for treating recurrent UFs after HIFU. Myomectomy for treating recurrent UFs resulted in a shorter operative and hospital stay, reduced blood loss, faster postoperative recovery, and fewer complications, better symptom relief rates, and lower risk of recurrence or reintervention. These findings indicate that previous HIFU ablation does not worsen the outcomes of the subsequent myomectomy.

An artificial intelligence-based bone age assessment model for Han and Tibetan children.

Background: Manual bone age assessment (BAA) is associated with longer interpretation time and higher cost and variability, thus posing challenges in areas with restricted medical facilities, such as the high-altitude Tibetan Plateau. The application of artificial intelligence (AI) for automating BAA could facilitate resolving this issue. This study aimed to develop an AI-based BAA model for Han and Tibetan children. Methods: A model named "EVG-BANet" was trained using three datasets, including the Radiology Society of North America (RSNA) dataset (training set n = 12611, validation set n = 1425, and test set n = 200), the Radiological Hand Pose Estimation (RHPE) dataset (training set n = 5491, validation set n = 713, and test set n = 79), and a self-established local dataset [training set n = 825 and test set n = 351 (Han n = 216 and Tibetan n = 135)]. An open-access state-of-the-art model BoNet was used for comparison. The accuracy and generalizability of the two models were evaluated using the abovementioned three test sets and an external test set (n = 256, all were Tibetan). Mean absolute difference (MAD) and accuracy within 1 year were used as indicators. Bias was evaluated by comparing the MAD between the demographic groups. Results: EVG-BANet outperformed BoNet in the MAD on the RHPE test set (0.52 vs. 0.63 years, p < 0.001), the local test set (0.47 vs. 0.62 years, p < 0.001), and the external test set (0.53 vs. 0.66 years, p < 0.001) and exhibited a comparable MAD on the RSNA test set (0.34 vs. 0.35 years, p = 0.934). EVG-BANet achieved accuracy within 1 year of 97.7% on the local test set (BoNet 90%, p < 0.001) and 89.5% on the external test set (BoNet 85.5%, p = 0.066). EVG-BANet showed no bias in the local test set but exhibited a bias related to chronological age in the external test set. Conclusion: EVG-BANet can accurately predict the bone age (BA) for both Han children and Tibetan children living in the Tibetan Plateau with limited healthcare facilities.

Deciphering the molecular toolkit: regulatory elements governing shell biomineralization in marine molluscs.

The intricate process of shell biomineralization in marine molluscs is governed by a complex interplay of regulatory elements, encompassing secretomes, transporters, and noncoding RNA. This review delves into recent advancements in understanding these regulatory mechanisms, emphasizing their significance in elucidating the functions and evolutionary dynamics of the molluscan shell biomineralization process. Central to this intricate orchestration are secretomes with diverse functional domains, selectively exported to the extrapallial space, which directly regulate crystal growth and morphology. Transporters are crucial for substrate transportation in the calcification and maintenance of cellular homeostasis. Beyond proteins and transporters, noncoding RNA molecules are integral components influencing shell biomineralization. This review underscores the nonnegligible roles played by these genetic elements at the molecular level. To comprehend the complexity of biomineralization in mollusc, we explore the origin and evolutionary history of regulatory elements, primarily secretomes. While some elements have recently evolved, others are ancient genes that have been co-opted into the biomineralization toolkit. These elements undergo structural and functional evolution through rapidly evolving repetitive low-complexity domains and domain gain/loss/rearrangements, ultimately shaping a distinctive set of secretomes characterized by both conserved features and evolutionary innovations. This comprehensive review enhances our understanding of molluscan biomineralization at the molecular and genetic levels.

Autophagy contributes to increase the content of intracellular free amino acids in hard clam (Mercenaria mercenaria) during prolonged exposure to hypersaline environments.

Marine bivalves in intertidal zones and land-based seawater ponds are constantly subjected to a wide range of salinity fluctuations due to heavy rainfall, intense drought, and human activities. As osmoconformers, bivalves rely primarily on rapid release or accumulation of free amino acids (FAAs) for osmoregulation. Euryhaline bivalves are capable of withstanding hyposaline and hypersaline environments through regulation of physiology, metabolism, and gene expression. However, current understanding of the molecular mechanisms underlying osmoregulation and salinity adaptation in euryhaline bivalves remains largely limited. In this study, RNA-seq, WGCNA and flow cytometric analysis were performed to investigate the physiological responses of hard clams (Mercenaria mercenaria) to acute short-term hyposalinity (AL) and hypersalinity (AH), and chronic long-term hyposalinity (CL) and hypersalinity (CH) stress. We found that amino acids biosynthesis was significantly inhibited and aminoacyl-tRNA biosynthesis was augmented to decrease intracellular osmolarity during hyposaline exposure. Under CH, numerous autophagy-related genes (ATGs) were highly expressed, and the autophagy activity of gill cells were significantly up-regulated. A significant decrease in total FAAs content was observed in gills after NH4Cl treatment, indicating that autophagy was crucial for osmoregulation in hard clams during prolonged exposure to hypersaline environments. To prevent premature or unnecessary apoptosis, the expression of cathepsin L was inhibited under AL and AH, and inhibitors of apoptosis was augmented under CL and CH. Additionally, neuroendocrine regulation was involved in salinity adaption in hard clams. This study provides novel insights into the physiological responses of euryhaline marine bivalves to hyposaline and hypersaline environments.

Chromosome-level genome assembly of the caenogastropod snail Rapana venosa.

The carnivorous gastropod Rapana venosa (Valenciennes, 1846) is one of the most notorious ecological invaders worldwide. Here, we present the first high-quality chromosome-scale reference R. venosa genome obtained via PacBio sequencing, Illumina paired-end sequencing, and high-throughput chromosome conformation capture scaffolding. The assembled genome has a size of 2.30 Gb, with a scaffold N50 length of 64.63 Mb, and is anchored to 35 chromosomes. It contains 29,649 protein-coding genes, 77.22% of which were functionally annotated. Given its high heterozygosity (1.41%) and large proportion of repeat sequences (57.72%), it is one of the most complex genome assemblies. This chromosome-level genome assembly of R. venosa is an important resource for understanding molluscan evolutionary adaption and provides a genetic basis for its biological invasion control.

Molecular evidence for the adaptive evolution in euryhaline bivalves.

Marine bivalves inhabiting intertidal and estuarine areas are frequently exposed to salinity stress due to persistent rainfall and drought. Through prolonged adaptive evolution, numerous bivalves have developed eurysalinity, which are capable of tolerating a wide range of salinity fluctuations through the sophisticated regulation of physiological metabolism. Current research has predominantly focused on investigating the physiological responses of bivalves to salinity stress, leaving a significant gap in our understanding of the adaptive evolutionary characteristics in euryhaline bivalves. Here, comparative genomics analyses were performed in two groups of bivalve species, including 7 euryhaline species and 5 stenohaline species. We identified 24 significantly expanded gene families and 659 positively selected genes in euryhaline bivalves. A significant co-expansion of solute carrier family 23 (SLC23) facilitates the transmembrane transport of ascorbic acids in euryhaline bivalves. Positive selection of antioxidant genes, such as GST and TXNRD, augments the capacity of active oxygen species (ROS) scavenging under salinity stress. Additionally, we found that the positively selected genes were significantly enriched in KEGG pathways associated with carbohydrates, lipids and amino acids metabolism (ALDH, ADH, and GLS), as well as GO terms related to transmembrane transport and inorganic anion transport (SLC22, CLCND, and VDCC). Positive selection of MCT might contribute to prevent excessive accumulation of intracellular lactic acids during anaerobic metabolism. Positive selection of PLA2 potentially promote the removal of damaged membranes lipids under salinity stress. Our findings suggest that adaptive evolution has occurred in osmoregulation, ROS scavenging, energy metabolism, and membrane lipids adjustments in euryhaline bivalves. This study enhances our understanding of the molecular mechanisms underlying the remarkable salinity adaption of euryhaline bivalves.

Molecular response and developmental speculations in metamorphosis of the veined rapa whelk, Rapana venosa.

Metamorphosis is the short developmental stage characterized by dramatic ontogenetic changes that occurs in most animals. However, this important process remains largely unclear in marine invertebrates. In this study, we performed the sequential RNA sequencing of a representative mollusk, the rapa whelk (Rapana venosa), that is undergoing metamorphosis and conducted differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) to investigate the overall and dynamic transcriptome responses. The results revealed that the expression of cytochrome P450 2A and 3A were upregulated during metamorphosis, while the expression of H/ACA ribonucleoproteins increased 4 h after metamorphosis induction (M4 stage), indicating that R. venosa mainly responded to the pelagobenthic changes. At the M24 stage, the enrichment of V-type proton ATPase and insulin indicated the complete development of secretory organs and initiation of hormone secretion. Furthermore, at the M48 stage, the enrichment of zinc metalloproteinase and conotoxin indicated a well-developed predation system that requires exogenous nutrition. Finally, during the PL stage, the genes associated with growth control were highly enriched, implying that R. venosa had completed metamorphosis and has entered the period of rapid growth. Therefore, our study provides useful transcriptomic resources for R. venosa and contributes new insights that may assist in elucidating the mechanisms underlying metamorphosis in marine invertebrates.

Integrated mRNA and miRNA transcriptomic analysis reveals the response of Rapana venosa to the metamorphic inducer (juvenile oysters).

Metamorphosis, as a critical developmental event, controls the population dynamics of most marine invertebrates, especially some carnivorous gastropods that feed on bivalves, whose population dynamics not only affect the maintenance of the ecological balance but also impact the protection of bivalve resources; therefore, the metamorphosis of carnivorous gastropods deserve attention. Here, we investigated the mechanism underlying the response of the carnivorous gastropod Rapana venosa to its metamorphic inducer juvenile oysters through integrated analysis of miRNA and mRNA profiles. According to the results, we speculated that the AMPK signaling pathway may be the critical regulator in the response to juvenile oysters in R. venosa competent larvae. The NF-kB and JAK-STAT signaling pathways that regulated apoptosis were also activated by the metamorphic inducer, which may result in the degeneration of the velum. Additionally, the significant changes in the expression of the SARP-19 precursor gene and protein cibby homolog 1-like gene may indicate that these signaling pathways also regulate growth and development during metamorphosis. This study provides further evidence that juvenile oysters can induce metamorphosis of R. venosa at the transcriptional level, which expands our understanding of the metamorphosis mechanism in carnivorous gastropods.