A Potential Role of Bone Morphogenetic Protein 7 in Shell Formation and Growth in the Razor Clam Sinonovacula constricta

Abstract

Bone morphogenetic proteins (BMPs) not only play essential roles in bone development but also are involved in embryonic growth, organogenesis cell proliferation and differentiation. However, the previous studies on the functions of shellfish BMPs genes are still very limited. To better understand its molecular structure and biological function, BMP7 of the razor clam Sinonovacula constricta ( Sc-BMP 7) was cloned and characterized in this study. The full length of Sc-BMP7 is 2252 bp, including an open reading frame (ORF) of 1257 bp encoding 418 amino acids. The protein sequence included a signal peptide (1–32 aa), a prodomain (38–270 aa) and a TGF-β domain (317–418 aa). The quantitative expression of eleven adult tissues showed that Sc-BMP 7 was significantly higher expressed in the gill, foot, and mantle ( P < 0.05), but lower in hemocytes and hepatopancreas. In the early development stages, low expression was detected in the stages of unfertilized mature eggs, fertilized eggs, 4-cell embryos, blastula, gastrulae, whereas it increased after the stage of trochophore and demonstrated the highest expression in umbo larvae ( P < 0.01). In shell repair experiment, Sc-BMP 7 showed increasing expression level after 12 h. The higher expression of Sc-BMP 7 was detected while Ca 2+ concentration was reduced in seawater. After inhibiting Sc-BMP 7 expression using RNA interference (RNAi) technology, expression of Sc-BMP 7 mRNA and protein were significantly down-regulated ( P < 0.05) in the central zone of mantle (nacre formation related tissue) and the pallial zone of mantle (prismatic layer formation related tissue). Association analysis identified two shared SNPs in exon of Sc-BMP 7 gene from 246 individuals of two groups. These results indicated that BMP 7 might be involved in shell formation and growth. These results would contribute to clarify the role of Sc-BMP 7 in the regulation of growth and shell formation, and provide growth-related markers for molecular marker assisted breeding of this species.

Vital Role of Glutamate Dehydrogenase Gene in Ammonia Detoxification and the Association Between its SNPs and Ammonia Tolerance in Sinonovacula constricta

“…It has been proposed that SNP, a molecular genetic marker of the third generation, has a good application prospect in population genetic analysis of aquatic animal, molecular marker–assisted selection (MAS) and biological evolution ( Wenne, 2017 ). Increasing evidence has shown that some SNPs are associated with growth, disease resistance, and other economic traits of clams ( He et al, 2012 ; Siva et al, 2012 , 2016 ; Nie et al, 2015 ; Niu et al, 2015 ; Yao et al, 2020 ; Zhao et al, 2020 ). For instance, a synonymous mutation SNP c.852A > G of insulin-like growth factor 2 mRNA-binding protein gene in Patinopecten yessoensis showed a significant association with the growth traits ( Ning et al, 2018 ), while two SNPs HbIIA-E2-146 and HbIIB-E2-23 of the hemoglobin gene ( Hb ) in Tegillarca granosa were associated with the Vibrio parahaemolyticus resistance ( Bao et al, 2013 ).…”

Characterizing the Role of Glutamine synthetase Gene on Ammonia Nitrogen Detoxification Metabolism of the Razor Clam Sinonovacula constricta

“…In addition, dsRNA of PfN23 gene was injected into the adult pearl oyster (Pinctada fucata), resulting in a disordered of nacre surface, suggesting that PfN23 gene may be a key accelerator in the control of crystal growth in nacre (Fang et al, 2012). Similarly, the expression of the BMP7 gene was successfully suppressed by injecting dsRNA into the razor clam, indicating that the BMP7 gene plays a vital role in repairing shell damage (Zhao et al, 2020). Moreover, in our previous study, the silencing of Glutamate dehydrogenase, a gene related to ammonia nitrogen detoxification, was induced by the injection of specific siRNA into the razor clam (Sun et al, 2021).…”

Molecular Characterization and Function of Bone Morphogenetic Protein 7 (BMP7) in the Pacific Abalone, Haliotis discus hannai

“…The TGF-β superfamily includes TGF-βs, growth differentiation factors (GDFs), bone morphogenetic proteins (BMPs), Inhibins/Activins, and Nodal. All members of the TGF-β superfamily release mature polypeptides by division of precursors at specific sites, and the activity relies on the formation of dimers from the same or different subunits [ 6 , 7 ]. Although the TGF-β family contains many diverse factors, they all signal via conserved signaling pathways.…”

“…The interaction between Smads and other signaling proteins mediates regulatory signals, controlling the expression of target genes, the translation of mRNA translation, and the regulation of cytoplasmic protein [ 8 , 9 , 10 , 11 ]. In recent years, the TGF-β superfamily has been found to play a critical role in the growth and development of shellfish [ 7 , 12 , 13 , 14 ].…”

“…BMPs are widely expressed during the development of mammals, with many biological activities, such as development, proliferation, etc. [ 7 , 16 ]. BMPs can distinguish between serine and threonine kinase receptors and bind to them, and the subsequent signaling is mediated by Smad-dependent and -independent pathways [ 7 , 17 , 18 ].…”