Genome-wide identification and expression analysis of Sox gene family in the Manila clam (Ruditapes philippinarum).

Sox transcription factors are vital in numerous fundamental biological processes. In this study, nine Sox gene family members were discovered in the Ruditapes philippinarum genome, classified into the SoxB1, SoxB2, SoxC, SoxD, SoxE, and SoxF groups, marking the first genome-wide identification of this gene family in R. philippinarum. Analyses of phylogeny, exon-intron structures, and domains bolster the support for their categorization and annotation. Furthermore, transcriptomic analyses across various developmental stages revealed that RpSox4, RpSox5, RpSox9, and RpSox11 were significantly expressed in the D-larval stage. Additionally, investigations into transcriptomes of clams with different shell colors indicated that most sox genes exhibited their highest expression levels in orange clams, followed by zebra, white zebra, and white clams, and the results of transcriptomes analysis in different tissues indicated that 8 Sox genes (except RpSox17) were highly expressed in the mantle tissue. Moreover, qPCR was used to detect the expression of Sox gene in R. philippinarum at different developmental periods, different shell colors and different tissues, and the results showed consistency with those of the transcriptomes. This study's findings lay the groundwork for additional exploration into the role of the Sox gene in melanin production in R. philippinarum shells.

Physiological and transcriptomic analysis provides new insights into osmoregulation mechanism of Ruditapes philippinarum under low and high salinity stress.

The Manila clam (Ruditapes philippinarum) is a commercially important marine bivalve, which inhabits the estuarine and mudflat areas. The osmoregulation is of great significance for molluscs adaptation to salinity fluctuations. In this study, we investigated the effects of low salinity (10 psu) and high salinity (40 psu) stress on survival and osmoregulation of the R. philippinarum. The results of physiological parameters showed that the ion (Na+, K+, Cl-) concentrations and Na+/K+-ATPase (NKA) activity of R. philippinarum decreased significantly under low salinity stress, but increased significantly under high salinity stress, indicating that there are differences in physiological adaptation of osmoregulation of R. philippinarum. In addition, we conducted the transcriptome analysis in the gills of R. philippinarum exposed to low (10 psu) and high (40 psu) salinity challenge for 48 h using RNA-seq technology. A total of 153 and 640 differentially expressed genes (DEGs) were identified in the low salinity (LS) group and high salinity (HS) group, respectively. The immune (IAP, TLR6, C1QL4, Ank3), ion transport (Slc34a2, SLC39A14), energy metabolism (PCK1, LDLRA, ACOX1) and DNA damage repair-related genes (Gadd45g, HSP70B2, GATA4) as well as FoxO, protein processing in endoplasmic reticulum and endocytosis pathways were involved in osmoregulation under low salinity stress of R. philippinarum. Conversely, the ion transport (SLC6A7, SLC6A9, SLC6A14, TRPM2), amino acid metabolism (GS, TauD, ABAT, ALDH4A1) and immune-related genes (MAP2K6, BIRC7A, CTSK, GVIN1), and amino acid metabolism pathways (beta-Alanine, Alanine, aspartate and glutamate, Glutathione) were involved in the process of osmoregulation under high salinity stress. The results obtained here revealed the difference of osmoregulation mechanism of R. philippinarum under low and high salinity stress through physiological and molecular levels. This study contributes to the assessment of salinity adaptation of bivalves in the context of climate change and provides useful information for marine resource conservation and aquaculture.

The lgi-miR-2d is Potentially Involved in Shell Melanin Synthesis by Targeting mitf in Manila Clam Ruditapes philippinarum.

Shell color as an important economic trait is also the crucial target trait for breeding and production. MicroRNA (miRNA) is an endogenous small non-coding RNA that can post-transcriptionally regulate the expression of target genes, it plays important roles in many life activities and physiological processes, such as shell color, stress response, and disease traits. In this study, we investigated the function of lgi-miR-2d in shell melanin formation and the expression patterns of lgi-miR-2d and target gene Rpmitf in Manila clam Ruditapes philippinarum. We further explored and verified the relationship between Rpmitf and lgi-miR-2d and identified the expression level of shell color-related gene changes by RNAi and injecting the antagomir of lgi-miR-2d, respectively. Our results indicated that lgi-miR-2d antagomir affected the expression of its target gene Rpmitf. In addition, the dual-luciferase reporter assay was conducted to confirm the direct interaction between lgi-miR-2d and Rpmitf. The results showed that the expression levels of melanin-related genes such as Rpmitf and tyr were significantly decreased in the positive treatment group compared with the blank control group after the Rpmitf dsRNA injection, indicating Rpmitf plays a crucial role in the melanin synthesis pathway. Taken together, we speculated that lgi-miR-2d might be negatively modulating Rpmitf, which might regulate other shell color-related genes, thereby affecting melanin synthesis in R. philippinarum.

Transcriptome analysis provides new insights into the immune response of Ruditapes philippinarum infected with Vibrio alginolyticus.

Manila clam (Ruditapes philippinarum) is a bivalve species with commercial value, but it is easily infected by pathogenic microorganisms in aquaculture, which restricts the shellfish industry. Notably, the impact of Vibrio alginolyticus on clam culture is obvious. In this study, RNA-seq was performed to analyze clam hepatopancreas tissue in 48 h (challenge group, G48h) and 96 h (challenge group, G96h) after infection with V. alginolyticus and 0 h after injection of PBS (control group, C). The results showed that a total of 1670 differentially expressed genes were detected in the G48h vs C group, and 1427 differentially expressed genes were detected in the G96h vs C group. In addition, KEGG analysis showed that DEGs were significantly enriched in pathways such as Lysosome and Mitophagy. Moreover, 15 immune related DEGs were selected for qRT-PCR analysis to verify the accuracy of RNA-seq, and the results showed that the expression level of DEGs was consistent with that of RNA-seq. Therefore, the results obtained in this study provides a preliminary understanding of the immune defense of R. philippinarum and molecular insights for genetic breeding of V. alginolyticus resistance in Manila clam.

Comprehensive analysis of differentially expressed mRNA, lncRNA and miRNA, and their ceRNA networks in the regulation of shell color in the Manila clam (Ruditapes philippinarum).

The regulatory mechanism of ceRNA network plays an important role in molecular function and biological processes, however, the molecular mechanism in the shell color of Ruditapes philippinarum has not yet been reported. In this study, we performed transcriptome sequencing on the mantle of R. philippinarum with different shell colors, and screened for mRNA, miRNA, and lncRNA. A total of 61 mRNAs, 3725 lncRNAs and 90 miRNAs were obtained from all the shell color comparison groups (all mRNAs, lncRNAs and miRNAs P < 0.05), and 7 mRNAs, 8 lncRNAs, and 4 miRNAs of the porphyrin pathway and melanin pathway were screened for competitive endogenous RNA (ceRNA) network construction. The results indicate that the ceRNA network composed of mRNA and lncRNA, centered around efu-miR-101, mle-bantam-3p, egr-miR-9-5p, and sma-miR-75p, may play a crucial regulatory role in shell color formation. This study reveals for the first time the mechanism of ceRNA regulatory networks in the shell color of R. philippinarum and providing important reference data for molecular breeding of shell color in R. philippinarum.

Sustainable development of urban agglomeration based on material metabolism: a case study on Fujian Delta, China.

As highly concentrated urbanized areas, urban agglomerations bear increasing resource depletion and environmental pressures, which threaten the regional sustainable development. Resource and environmental problems arising from the process of urbanization can be attributed to the dislocation or maladjustment of material metabolism in time or space. Conducting research on material metabolism at the level of urban agglomerations is helpful in finding the root causes of environmental problems to provide support for the reduction of regional resource consumption and pollution emissions. The material metabolism characteristics of the urban agglomeration and internal cities of the Fujian Delta Urban Agglomeration (FDUA) in China are evaluated using the material flow analysis. The following results are observed. (1) The economic development of the FDUA is still at risk of resource consumption, and a large proportion of hidden flow (HF > 80%) drags down the overall metabolic efficiency and sustainable development. (2) The discharge of various pollutants in the FDUA generally shows a downward trend. Improving metabolic efficiency, delayed MCI growth, and improved overall regional environmental quality are observed. (3) Cities that have relatively scarce land resources but are economically developed, such as Xiamen, still bear a relatively heavy ecological burden (ECdmc > 1). (4) Regional collaboration is conducive to the sustainable development of multiple regions. On the one hand, the results of this study provide decision-making basis for the sustainable development of the national ecological civilization demonstration area. On the other hand, this work guides the establishment of a comprehensive industrial linkage and cooperation mechanism for the same type of small- and medium-sized urban agglomerations.

Genome-Wide Identification and Characterization of MITF Genes in Ruditapes philippinarum and Their Involvement in the Immune Response to Vibrio anguillarum Infection.

Studies have shown that the shellfish have innate immune system, which is a very important immune form of shellfish, and they rely on the innate immune system to resist diseases. As a transcription factor, Microphthalmia-associated transcription factor (MITF) plays a regulatory role in immune response and the shell color is also an important index for the breeding of excellent varieties of R. philippinarum. The research on immune response mechanism of RPMITFs can provide important reference data for the breeding of excellent clam varieties. In the genome of R. philippinarum, the RPMITF genes family of shell color-related gene family was selected as the target gene of this experiment. There are 12 RpMITF genes named RpMITF1, RpMITF2, RpMITF3, RpMITF4, RpMITF5, RpMITF6, RpMITF7, RpMITF8, RpMITF9, RpMITF10, RpMITF11, and RpMITF12. The open reading frame length is 639, 1233, 996, 1239, 675, 624, 816, 1365, 612, 1614, 1122, and 486 bp, encoding 212, 410, 331, 412, 224, 207, 271, 454, 203, 537, 373, and 161 aa, respectively. The predicted molecular weight range of amino acids is 18.85-62.61 kda, and the isoelectric point range is 5.26-9.44. Real-time quantitative PCR was used to detect the gene expression of RpMITF gene family in hepatopancreas tissues of two populations of Manila clam at 6 time points (0, 3, 6, 12, 24, and 48 h) after Vibrio anguillarum stress. The results show that RpMITF gene family was significantly expressed in hepatopancreas of two clam populations after V. anguillarum stress (P < 0.05).

Revealing the potential regulatory relationship between HSP70, HSP90 and HSF genes under temperature stress.

Heat Shock Protein (HSPs) gene family members play fundamental roles in different environmental stress tolerances, protect the structure and function of cells, and perform a significant task in cellular homeostasis. In this study, we conducted a genome-wide identification, evolutionary relationship analysis and gene expression analysis of the HSP70, HSP90, and HSF gene families in Ruditapes philippinarum. We identified 83 RpHSP70, 6 RpHSP90, and 3 RpHSF genes in R. philippinarum. The structural characteristics, chromosomal localization, and the gene structure map were constructed to reveal the characteristics of protein structures. Furthermore, the expression profiling of transcriptome data showed the expression pattern of HSP70, HSP90 and HSF genes in Manila clam from different populations, and under high and low temperature stress. In addition, we performed protein-protein interaction network analysis between HSP70, HSP90, and HSF gene family which enabled us to recognize the regulatory relationship between the two HSP gene families and the HSF gene family. Furthermore, the predicted sub-cellular location revealed a diversified subcellular distribution of HSP70, HSP90, and HSF proteins, which may be directly or indirectly associated with functional diversification under heat stress condition.

iTRAQ-based proteomic analysis reveals proteins associated with cold stress response in two different populations of Manila clam (Ruditapes philippinarum).

Water temperature is one of the key environmental factors for marine ectotherms and a change in temperature beyond and organism's capacity limits can cause a series of changes to physiological state and damage to the organism. Understanding how organisms adapt to complex environments is a central goal of evolutionary biology and ecology. Ruditapes philippinarum is an ecologically and scientifically important marine bivalve species. To uncover the molecular mechanisms of acclimation of R. philippinarum to low-temperature stress, iTRAQ-based quantitative proteomics was conducted to compare the proteomes of the north and south populations of R. philippinarum under low-temperature stress. The results showed a total of 6355 and 6352 proteins were identified in two populations, respectively. Among these, 94 and 83 were differentially abundant proteins (DAPs), and most of DAPs were related to oxidation-process, protein binding, or an integral component of membrane. According to the results of KEGG pathway enrichment analysis, most of DAPs in both populations are involved in immune-related pathways, while other population-specific significant abundance proteins of south population and north population were enriched in biosynthesis of amino acids (Enolase, Glutamine synthetase) and unsaturated fatty acids pathways (3-ketoacyl-CoA thiolase, Stearoyl-CoA desaturase), respectively, indicating that two population of clams may have different cold-stress regulation mechanisms. Our study provides new insights into different cold stress tolerance mechanisms in northern and southern populations of R. philippinarum using iTRAQ-based proteomics. This work contributes to a better understanding of molecular basis on cold stress response and adaptations, which shed lights on evolutionary biology and general ecophysiology of R. philippinarum.

Transient receptor potential (TRP) channels in the Manila clam (Ruditapes philippinarum): Characterization and expression patterns of the TRP gene family under heat stress in Manila clams based on genome-wide identification.

In this study, we identified a total of 40 transient receptor potential genes (RpTRP) in Manila clam by genome-wide identification and classified them into four categories (TRPV, TRPA, TRPM, TRPC) based on gene structure and subfamily relationships. The protein length of RpTRP genes ranges from 281 amino acids to 1601 amino acids. Molecular weight and theoretical PI values range from 182.82 kDa to 32.43 kDa, respectively, with PI values between 5.17 and 9.25. By comparing the expression profiles of TRP genes during heat stress in Manila clams at different latitudes, we found that most genes in the TRP gene family were up-regulated in expression during heat challenge. Therefore, we determined that TRP genes have an important role in the heat stress of Manila clams. This work provides a basis for further studies on the molecular mechanisms of TRP-mediated heat tolerance in Manila clam and for explaining differences in heat tolerance in Manila clam at different latitudes through key differential TRP genes at the molecular level.

Metabolomic analysis provides new insights into the heat-hardening response of Manila clam (Ruditapes philippinarum) to high temperature stress.

The temperature has always been a key environmental factor in Manila clam (Ruditapes philippinarum) culture. In this study, the Manila clam was treated to different temperature pre-heat (28 °C, 30 °C) and gained heat tolerance after recover of 12 h, and a survival rate (14.7 %-49.1 %) advantage after high temperature challenge (30 and 32 °C). To further investigate the physiological and metabolism changes in Manila clam that had experienced a heat stress, non-targeted metabolomics (LC-MS/MS) was used to analyze the metabolic responses of gills in three group Manila clams during the heat challenge. Metabolic profiles revealed that high temperature caused changes in fatty acid composition, energy metabolism, antioxidant metabolites, hydroxyl compounds, and amino acids in heat-hardened clams compared to non-hardened clams. We found a number of significantly enriched pathways, including cAMP signaling pathway, serotonergic synapse, and biosynthesis of unsaturated fatty acids in heat-hardened Manila clam compared with non-hardened and untreated Manila clam. After a brief high temperature treatment, the physiological maintenance ability of Manila clam was improved. Combined with metabolomics analysis, heat hardening treatment may improve the energy metabolism and antioxidant ability of Manila clam. These results provide new insights into the cellular and metabolic responses of Manila clams following high temperature stress.

Genome-wide investigation and expression analysis of TLR gene family reveals its immune role in Vibrio tolerance challenge of Manila clam.

Toll-like receptors (TLRs) play key roles in activating immune responses during infection. In this study, we identified TLR genes in Manila clam at the genome-wide level and characterized it into 9 types according to the Ruditapes philippinarum genome annotation, including TLR1 (1-10), TLR2 (1-10), TLR2-2 (1-5), TLR3 (1-3), TLR4 (1-9), TLR5, TLR6 (1-5), TLR7 (1-2), and TLR13 (1-4). The length of TLR proteins varied from 128 to 1257 amino acids. The molecular weights and theoretical isoelectric point (pI) values ranged from 14.63 to 143.32 kDa and 4.47 to 9.45, respectively. TLR genes showed universal expression levels in adductor muscle (AM), mantle (M), foot (F), gill (GI), pipe (P), digestive gland (DG), gonad (GO) and labial palp (L). Transcriptome analysis revealed that the expression level of TLR4, TLR5, TLR7 and TLR13 genes are significantly highly expressed in resistant individuals of Manila clam under Vibrio anguillarum challenge, indicating these TLR genes may play significant roles in response to invading pathogens. The results obtained in this work will provide valuable insights into the immune function of TLR gene in R. philippinarum.

Effects of high water temperature on physiology, survival, and resistance to high temperature air-exposure in the Manila clam Ruditapes philippinarum.

Ruditapes philippinarum is a typical burrowing shellfish, living in the intertidal zone. In natural conditions, the mortality of R. philippinarum is most affected by high water temperatures, high temperature air-exposure, and other environmental stresses. In this study, the mortality rates of the two populations of R. philippinarum under high water temperature stress were recorded, and catalase (CAT), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) antioxidant enzyme activities in the hepatopancreas were analyzed. The results showed that the survival times of cultured clams were longer than those of wild clams after acute high temperature stress. CAT, SOD, and T-AOC activities increased after acute high water temperature and high temperature air-exposure stress. These antioxidant enzyme activities gradually decreased to their initial levels after 2 days of recovery from these high temperature stresses. Based on these experimental results, we found that the cultured clam population had better heat and high temperature air-exposure resistances than the wild clams. CAT, SOD, and T-AOC enzymes play an important role in the antioxidant processes of R. philippinarum in response to high water temperature and high temperature air-exposure. This study provided a theoretical basis for the development of healthy aquacultural practices for these shellfish.

Examination of the potential roles of insulin-like peptide receptor in regulating the growth of Manila clam Ruditapes philippinarum.

The role of insulin/insulin-like growth factor (IGF) signaling pathway in the growth regulation of marine invertebrates has not been fully studied. In this study, the economically important species Ruditapes philippinarum was sacrificed to clarify the role of IGF system in the growth regulation of R. philippinarum by real-time quantitative PCR. Systematic bioinformatics analysis can identify the major genes of IGF signaling pathway and insulin-like peptide receptor (ILPR) - mediated signaling pathway in R. philippinarum. The expression levels of IGF and its downstream signaling pathway genes in larger clams were significantly higher than those in small clams, indicating that they were involved in the growth regulation of R. philippinarum. These results suggest that IGF signaling pathway and ILPR mediated signaling pathway to regulate the growth of R. philippinarum.

Comparative transcriptomic analysis revealed dynamic changes of distinct classes of genes during development of the Manila clam (Ruditapes philippinarum).

BACKGROUND: The Manila clam Ruditapesphilippinarum is one of the most economically important marine shellfish. However, the molecular mechanisms of early development in Manila clams are largely unknown. In this study, we collected samples from 13 stages of early development in Manila clam and compared the mRNA expression pattern between samples by RNA-seq techniques. RESULTS: We applied RNA-seq technology to 13 embryonic and larval stages of the Manila clam to identify critical genes and pathways involved in their development and biological characteristics. Important genes associated with different morphologies during the early fertilized egg, cell division, cell differentiation, hatching, and metamorphosis stages were identified. We detected the highest number of differentially expressed genes in the comparison of the pediveliger and single pipe juvenile stages, which is a time when biological characteristics greatly change during metamorphosis. Gene Ontology (GO) enrichment analysis showed that expression levels of microtubule protein-related molecules and Rho genes were upregulated and that GO terms such as ribosome, translation, and organelle were enriched in the early development stages of the Manila clam. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the foxo, wnt, and transforming growth factor-beta pathways were significantly enriched during early development. These results provide insights into the molecular mechanisms at work during different periods of early development of Manila clams. CONCLUSION: These transcriptomic data provide clues to the molecular mechanisms underlying the development of Manila clam larvae. These results will help to improve Manila clam reproduction and development.

A high-quality chromosome-level genome assembly of the bivalve mollusk Mactra veneriformis.

Mactra veneriformis (Bivalvia: Mactridae) is a bivalve mollusk of major economic importance in China. Decreased natural yields of M. veneriformis have led to an urgent need for genomic resources. To address this problem and the currently limited knowledge of molecular evolution in this genus, we here report a high-quality chromosome-level genome assembly of M. veneriformis. Our approach yielded a 939.32 Mb assembled genome with an N50 contig length of 7,977.84 kb. Hi-C scaffolding of the genome resulted in assembly of 19 pseudochromosomes. Repetitive elements made up ∼51.79% of the genome assembly. A total of 29,315 protein-coding genes (PCGs) were predicted in M. veneriformis. Construction of a genome-level phylogenetic tree demonstrated that M. veneriformis and Ruditapes philippinarum diverged around 231 million years ago (MYA). Inter-species comparisons revealed that 493 gene families have undergone expansion and 449 have undergone contraction in the M. veneriformis genome. Chromosome-based macrosynteny analysis revealed a high degree of synteny between the 19 chromosomes of M. veneriformis and those of Patinopecten yessoensis. These results suggested that M. veneriformis has a similar karyotype to that of P. yessoensis, and that a highly conserved 19-chromosome karyotype was formed in the early differentiation stages of bivalves. In summary, the genomic resources generated in this work serve as a valuable reference for investigating the molecular mechanisms underlying biological functions in M. veneriformis and will facilitate future genetic improvement and disease treatment in this economically important species. Furthermore, the assembled genome greatly improves our understanding of early genomic evolution of the Bivalvia.

Genome-wide identification and analysis of HECT E3 ubiquitin ligase gene family in Ruditapes philippinarum and their involvement in the response to heat stress and Vibrio anguillarum infection.

E3 ubiquitin ligase (E3s) plays an important role in ubiquitin proteasome pathway, proteins containing homologous E6-AP carboxyl terminus (HECT) domains. However, the role of HECT E3 ubiquitin ligase in mollusk was rarely explored. In this study, we performed a genome-wide analysis of the HECT domain-containing gene in Ruditapes philippinarum to identify and predict the structural and functional characterization of HECT genes in response to abiotic and biotic stress. A total of sixteen members of HECT gene family were identified and analyzed for the gene structure, phylogenetic relation, three-dimensional structure, protein interaction network, and expression patterns. Experimental results demonstrated that Rph.HUWE1, Rph.HECTD1, Rph.Ubr5 were significantly up-regulated in response to heat stress and bacterial challenge. Taken together, our data provide insights into the potential function of HECT E3 ligase in heat stress and Vibrio anguillarum infection.

Apextrin from Ruditapes philippinarum functions as pattern recognition receptor and modulates NF-κB pathway.

Apextrin belongs to ApeC-containing proteins (ACPs) and features a signal-peptide, an N-terminal membrane attack complex component/perforin (MACPF) domain, and a C-terminal ApeC domain. Recently, apextrin-like proteins were identified as pattern recognition receptor (PRR), which recognize the bacterial cell wall component and participate in innate immunity. Here, an apextrin (Rpape) was identified and characterized in Ruditapes philippinarum. Our results showed that Rpape mRNA was significantly induced under bacterial challenges. The Rpape recombinant protein exhibited a significant inhibitory effect on gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and bound with Vibrio anguillarum, S. aureus and B. subtilis. We found Rpape protein positively activated the NF-κB signaling cascade and increased the activity of Nitric oxide (NO). This study revealed the immunity role of apextrin in R. philippinarum and provided a reference for further study on the role of apextrin in bivalves.

Molecular Mechanisms Underlying Vibrio Tolerance in Ruditapes philippinarum Revealed by Comparative Transcriptome Profiling.

The clam Ruditapes philippinarum is an important species in the marine aquaculture industry in China. However, in recent years, the aquaculture of R. philippinarum has been negatively impacted by various bacterial pathogens. In this study, the transcriptome libraries of R. philippinarum showing different levels of resistance to challenge with Vibrio anguillarum were constructed and RNA-seq was performed using the Illumina sequencing platform. Host immune factors were identified that responded to V. anguillarum infection, including C-type lectin domain, glutathione S-transferase 9, lysozyme, methyltransferase FkbM domain, heat shock 70 kDa protein, Ras-like GTP-binding protein RHO, C1q, F-box and BTB/POZ domain protein zf-C2H2. Ten genes were selected and verified by RT-qPCR, and nine of the gene expression results were consistent with those of RNA-seq. The lectin gene in the phagosome pathway was expressed at a significantly higher level after V. anguillarum infection, which might indicate the role of lectin in the immune response to V. anguillarum. Comparing the results from R. philippinarum resistant and nonresistant to V. anguillarum increases our understanding of the resistant genes and key pathways related to Vibrio challenge in this species. The results obtained here provide a reference for future immunological research focusing on the response of R. philippinarum to V. anguillarum infection.

Gene Co-Expression Network Analysis Reveals the Correlation Patterns Among Genes in Different Temperature Stress Adaptation of Manila Clam.

The Manila clam (Ruditapes philippinarum) is one of the most important aquaculture species and widely distributed along the coasts of China, Japan, and Korea. Due to its wide distribution, it can tolerate a wide range of temperature. Studying the gene expression profiles of clam gills had found differentially expressed genes (DEGs) and pathway involved in temperature stress tolerance. A systematic study of cellular response to temperature stress may provide insights into the mechanism of acquired tolerance. Here, weighted gene co-expression network analysis (WGCNA) was carried out using RNA-seq data from gill transcriptome in response to high and low temperature stress. There are a total 32 gene modules, of which 18 gene modules were identified as temperature-related modules. Blue module was one significantly correlated with temperature which was associated with cellular metabolism, apoptosis pathway, ER stress, and others.