Transcriptomic analysis elucidates the molecular processes associated with hydrogen peroxide-induced diapause termination in Artemia-encysted embryos.

Bonien Chen,Ming-Chang Hong,Tsung-Meng Wu,Jui-Wen Ma,Wei-Kuang Wang,Kuohsun Chiu,Tah-Wei Chu,Chih-Ming Liang,Michael Schubert

doi:10.1371/journal.pone.0247160

Abstract

Treatment with hydrogen peroxide (H2O2) raises the hatching rate through the development and diapause termination of Artemia cysts. To comprehend the upstream genetic regulation of diapause termination activated by exterior H2O2 elements, an Illumina RNA-seq analysis was performed to recognize and assess comparative transcript amounts to explore the genetic regulation of H2O2 in starting the diapause termination of cysts in Artemia salina. We examined three groupings treated with no H2O2 (control), 180 μM H2O2 (low) and 1800 μM H2O2 (high). The results showed a total of 114,057 unigenes were identified, 41.22% of which were functionally annotated in at least one particular database. When compared to control group, 34 and 98 differentially expressed genes (DEGs) were upregulated in 180 μM and 1800 μM H2O2 treatments, respectively. On the other hand, 162 and 30 DEGs were downregulated in the 180 μM and 1800 μM H2O2 treatments, respectively. Cluster analysis of DEGs demonstrated significant patterns among these types of 3 groups. GO and KEGG enrichment analysis showed the DEGs involved in the regulation of blood coagulation (GO: 0030193; GO: 0050818), regulation of wound healing (GO:0061041), regulation of hemostasis (GO: 1900046), antigen processing and presentation (KO04612), the Hippo signaling pathway (KO04391), as well as the MAPK signaling pathway (KO04010). This research helped to define the diapause-related transcriptomes of Artemia cysts using RNA-seq technology, which might fill up a gap in the prevailing body of knowledge.

Highlights

During Artemia diapause, the metabolic process of egg cells reduces [1], thereby decreasing energy consumption; molecular chaperones are accustomed to prevent or decrease protein denaturation
The results showed that the hatching rate was 3.1 ± 0.90% in control group (0 μM H2O2); 47.5 ± 5.31% in low-H2O2 group (180 μM), and 4.4 ± 1.30% in high-H2O2 group (1800 μM)
Robbins et al [4] and Hong et al [9] have demonstrated that H2O2 increases the hatching rates of Artemia cysts and the hatching rates decreased in higher H2O2 than in lower H2O2 treatments

Summary

Introduction

During Artemia diapause, the metabolic process of egg cells reduces [1], thereby decreasing energy consumption; molecular chaperones are accustomed to prevent or decrease protein denaturation. Brine shrimp possess a solid, semipermeable outer shell that protects their embryos while making sure embryo contact with external circumstances. Brine shrimp contain trehalose, which exhibits a fluid retention capacity that protects embryos from lethal harm due to dehydration [2, 3]. Diapause termination of Artemia cysts was proven to be regulated by environmental elements. Robbins et al [4] indicated that the hatching rate of Artemia cysts improved by 50% when subjected to 180 μM hydrogen peroxide (H2O2). Based on the experimental outcomes obtained by these studies, chemical methods may be employed to terminate cyst diapause. The mechanism of diapause termination has not been elucidated and is a subject that warrants in-depth investigation

Methods

Results

Conclusion