title: WAFs lead molting retardation of naupliar stages with down-regulated expression profiles of chitin metabolic pathway and related genes in the copepod Tigriopus japonicus.
abstract: Oil pollution is considered being disastrous to marine organisms and ecosystems. As molting is critical in the developmental process of arthropods in general and copepods, in particular, the impact will be adverse if the target of spilled oil is on molting. Thus, we investigated the harmful effects of water accommodated fractions (WAFs) of crude oil with an emphasis on inhibition of chitin metabolic pathways related genes and developmental retardation in the copepod Tigriopus japonicus. Also, we analysed the ontology and domain of chitin metabolic pathway genes and mRNA expression patterns of developmental stage-specific genes. Further, the developmental retardation followed by transcriptional modulations in nuclear receptor genes (NR) and chitin metabolic pathway-related genes were observed in the WAFs-exposed T. japonicus. As a result, the developmental time was found significantly (P<0.05) delayed in response to 40% WAFs in comparison with that of control. Moreover, the NR gene, HR3 and chitinases (CHT9 and CHT10) were up-regulated in N4-5 stages, while chitin synthase genes (CHS-1, CHS-2-1, and CHS-2-2) down-regulated in response to WAFs. In brief, a high concentration of WAFs repressed nuclear receptor genes but elicited activation of some of the transcription factors at low concentration of WAFs, resulting in suppression of chitin synthesis. Thus, we suggest that WAF can lead molting retardation of naupliar stages in T. japonicus through down-regulations of chitin metabolism. These findings will provide a better understanding of the mode of action of chitin biosynthesis associated with molting mechanism in WAF-exposed T. japonicus.
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Hwang
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
authors.forename: Min-Chul
authors.initials: MC
authors.lastname: Lee
authors.affiliation: Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 04763, South Korea.
authors.forename: Do-Hyun
authors.initials: DH
authors.lastname: Kyung
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
authors.forename: Hui-Su
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
authors.forename: Jeonghoon
authors.initials: J
authors.lastname: Han
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 21990, South Korea.
authors.forename: Il-Chan
authors.initials: IC
authors.lastname: Kim
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea. Electronic address: Jayeshp24@skku.edu.
authors.forename: Jayesh
authors.initials: J
authors.lastname: Puthumana
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea. Electronic address: jslee2@skku.edu.
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000818:Animals; D002686:Chitin / Q000378:metabolism*; D033342:Copepoda / Q000187:drug effects* / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects* / Q000235:genetics; D053858:Metabolic Networks and Pathways / Q000187:drug effects* / Q000235:genetics; D018978:Molting / Q000187:drug effects* / Q000235:genetics; D010578:Petroleum / Q000009:adverse effects; D059392:Petroleum Pollution / Q000009:adverse effects; D059467:Transcriptome / Q000187:drug effects* / Q000235:genetics; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical; D014867:Water; D002686:Chitin
keywords: Chitin metabolic pathway; Copepod; Molting; Nuclear receptor; Tigriopus japonicus; Water accommodated fraction (WAF)