title: Improved tolerance of metals in contaminated oyster larvae.
abstract: Environmental stress experienced by parents may make a significant difference in the response of their offspring. However, relevant studies on marine bivalves are very limited especially for the field populations. In the present study, we examined the relative metal tolerance of offspring produced by four natural populations of oyster Crassostrea sikamea that were contaminated by metals to different degrees. We demonstrated that the resistance of oyster offspring to copper and zinc was correlated with the level of metal pollution experienced by the parent oysters. Specifically, the oyster embryo and larvae produced by adult oysters from contaminated sites had a much higher tolerance to metal stress than those from the reference sites. Furthermore, tissue concentration-dependent maternal transfer of Cu and Zn was found in this study, and the metallothionein concentrations in eggs were positively related to the total concentrations of maternally transferred Cu and Zn. Thus, the maternally transferred metals inducing high level of MT synthesis in eggs was one of the possible mechanisms responsible for the enhanced metal tolerance of oyster embryos and larvae from heavily contaminated sites. We concluded that environmental exposure history of adult oysters significantly influenced the ability of their offspring to cope with metal stress. Our findings offered the field evidence of the possible transfer of metal tolerance from adults to offspring in marine bivalves.
authors.affiliation: State Key Laboratory for Marine Environmental Science, College of Environment and Ecology, Xiamen University, Xiamen 361005, China.
authors.forename: Nanyan
authors.initials: N
authors.lastname: Weng
authors.affiliation: State Key Laboratory for Marine Environmental Science, College of Environment and Ecology, Xiamen University, Xiamen 361005, China; Division of Life Science, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Kowloon, Hong Kong. Electronic address: wwang@ust.hk.
authors.forename: Wen-Xiong
authors.initials: WX
authors.lastname: Wang
mesh_terms: D000818:Animals; D003300:Copper / Q000378:metabolism / Q000633:toxicity*; D049896:Crassostrea / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism; D010063:Ovum / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D015032:Zinc / Q000378:metabolism / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper; D008668:Metallothionein; D015032:Zinc
keywords: Copper; Crassostrea sikamea; Exposure history; Metallothionein; Tolerance; Zinc