Identification of hypoxia biomarker candidates from sea urchin (Strongylocentrotus nudus) coelomocyte by cDNA microarray.

Abstract

Dissolved oxygen is one of the most important factors controlling growth in aquatic organisms. Hypoxia is generally defined as dissolved oxygen less than 2.8 mg O2/L(equivalent to 2 mL O2/L or 91.4 mM). In this study, Increasing of red spherule cell and gene expression change by microarray analysis in sea urchin (Strongylocentrotus nudus) coelomocytes was accomplished to identify cellular stress of hypoxia condition. Adult sea urchins S. nudus were exposed to dissolved oxygen levels of 7.6 mg O2/L (normoxia), 4.7 mg O2/L and 1.8 mg O2/L (hypoxia), at 15°C and 33‰. The each coelomocytes of S. nudus were harvested at 0 hr, 6 hr, 12 hr and 24 hr. A significant increasing of the red spherule cells was observed hypoxic condition sample at 24 hr. To process molecular work, microarray analysis was investigated. This result showed that several genes in hypoxia group (24 hr) were significantly reduced than control group (normoxia, 0 hr). These genes (RNA processing and modification related genes: RNA helicase and pyrophosphatase DCP2, transcription related genes: CDP1 and GATA-4/5/6, Cell cycle control related gene: spindle pole body, Defence mechanism related gene: C-typelectin) were confirmed by qReal-time PCR. We identified that gene expression of hypoxia group was reduced by up to 20%-80% compared to normoxia group at 24 hr. RNA helicase and GATA-4/5/6 expression rate were also analyzed in thspherule cell and gene expression change by microarray analysis in sea urchin (Strongylocentrotus nudus) coelomocytes was accomplished to identify cellular stress of hypoxia condition. Adult sea urchins S. nudus were exposed to dissolved oxygen levels of 7.6 mg O2/L (normoxia), 4.7 mg O2/L and 1.8 mg O2/L (hypoxia), at 15°C and 33‰. The each coelomocytes of S. nudus were harvested at 0 hr, 6 hr, 12 hr and 24 hr. A significant increasing of the red spherule cells was observed hypoxic condition sample at 24 hr. To process molecular work, micr