Metabolomics analysis for skin ulceration syndrome of Apostichopus japonicus based on UPLC/Q-TOF MS

Skin ulceration syndrome(SUS)is the main diseases aff ected the development of sea cucumber(Apostichopus japonicus)culture industries.To better observe the changes in the sea cucumber A.japonicus with SUS and understand the pathogenesis of the disease,activities of superoxide dismutase(SOD),catalase(CAT),and level of malondialdehyde(MDA)in coelomic fluid were detected using the Assay Kit and metabolites in the body wall were assessed using ultra-performance liquid chromatography and quadrupole-time of flight mass spectrometry.The results indicated that level of MDA was increased during SUS compared with healthy individuals(P<0.01),but activities of SOD and CAT were reduced(P<0.05).In metabolomics analysis,metabolites,such as adenosine,choline,betaine aldehyde,palmitic acid,and taurine,were found to be upregulated and 2-oxoadipic acid,anthranilic acid(vitamin L1),thioetheramide-PC,cholesterol-3-sulfate,and pentadecanoic acid were downregulated(VIP>1 and P<0.1).Pathway enrichment analysis indicated most enrichment of KEGG pathways were mainly related to energy metabolism,immunity,and osmoregulation such as ABC transporters,glycine,serine and threonine metabolism,tryptophan metabolism and neuroactive ligand-receptor interaction.Our study reflected the difference in enzyme activity and metabolites between A.japonicus with SUS and those without,which will provide reference data for investigating SUS.

Molecular characterization and expression of the SiUCP2 gene in sea urchin Strongylocentrotus intermedius

Uncoupling protein 2 (UCP2) is a proton transporter located in the inner mitochondrial membrane, and inhibits the formation of adenosine triphosphate and reactive oxygen species by uncoupling oxidative phosphorylation. To provide a theoretical basis for the role of SiUCP2 in lipid metabolism, a 2 341-bp full-length cDNA of SiUCP2 from sea urchin Strongylocentrotus intermedius , which encodes 323 amino acids (predicted MW 36.11 kDa) was obtained, and the structure and function of the SiUCP2 gene and its expression at the mRNA and protein level were studied. SiUCP2 had high homology with UCP2 of other species. Expression of SiUCP2 was detected in the order of tube feet > gonads > coelomocytes > intestines. The expression level was the highest in prismatic larvae and lowest in the two-cell stage. Moreover, using in-situ hybridization, we found that SiUCP2 protein was expressed in the gonads and intestine. This study provided a theoretical basis for subsequent studies on the role of SiUCP2 and its regulatory mechanism in lipid metabolism, and for the improvement of gonad quality to obtain a higher economic value from sea urchins.

Fine‑mapping and association analysis of candidate genes for papilla number in sea cucumber,Apostichopus japonicus

The papilla number is one of the most economically important traits of sea cucumber in the China marketing trade.However,the genetic basis for papilla number diversity in holothurians is still scarce.In the present study,we conducted genomewide association studies(GWAS)for the trait papilla number of sea cucumbers utilizing a set of 400,186 high-quality SNPs derived from 200 sea cucumbers.Two significant trait-associated SNPs that passed Bonferroni correction(P<1.25E−7)were located in the intergenic region near PATS1 and the genic region of EIF4G,which were reported to play a pivotal role in cell growth and proliferation.The fine-mapping regions around the top two lead SNPs provided precise causative loci/genes related to papilla formation and cellular activity,including PPP2R3C,GBP1,and BCAS3.Potential SNPs with P<1E−4 were acquired for the following GO and KEGG enrichment analysis.Moreover,the two lead SNPs were verified in another population of sea cucumber,and the expressive detection of three potential candidate genes PATS1,PPP2R3C,and EIF4G that near or cover the two lead SNPs was conducted in papilla tissue of TG(Top papilla number group)and BG(Bottom papilla number group)by qRT-PCR.We found the significantly higher expression profile of PATS1(3.34-fold),PPP2R3C(4.90-fold),and EIF4G(4.23-fold)in TG,implying their potential function in papilla polymorphism.The present results provide valuable information to decipher the phenotype differences of the papilla trait and will provide a scientific basis for selective breeding in sea cucumbers.

Higher dietary protein increases growth performance,anti-oxidative enzymes activity and transcription of heat shock protein 70 in the juvenile sea urchin(Strongylocentrotus intermedius)under a heat stress

This study was conducted to investigate the effect of dietary protein concentration(12%,18%,24%,30% and 36%)on the growth performance,activity of anti-oxidative enzymes and heat shock protein 70(HSP70)transcription in the sea urchin(Strongylocentrotus intermedius)under a heat stress.After 112 days of feeding trial the sea urchins were heat stressed(26
C)and the coelomic fluid and intestine sampled at time 0 and 15 min,2 h and 6 h.The results showed that an increase in dietary protein(12%-24%),significantly increased(p<0.05)the sea urchin weight gain rate(WGR).As dietary protein increased(from 18% to 36%),the gonadosomatic index(GI)of juvenile sea urchins also significantly increased(p<0.05)from 18.0%to 22.6%.Superoxide dismutase(SOD)activity increased with dietary protein increase(12%-30%)and the enzyme activity was significantly higher(p<0.05)in the coelomic fluid of sea urchins that were fed with 30% diets when compared to 12% and 36% protein diets at all time points after the heat stress.Catalase(CAT)activity showed a similar tendency with the increase in dietary protein concentration at time 0 and 15 min after the heat stress(p<0.05).Transcription of HSP70 in the intestine also showed a similar trend to SOD and was highest in the animals that were fed with 30% protein diets(p<0.05).Our results suggest that 24% protein diets could meet the requirements for growth performance but a 30% protein diet resulted in improved gonad development and anti-heat stress capacity in this sea urchin species.