TY - JOUR
T1 - Effects of environmental contaminants on hemoglobin gene expression in daphnia magna
T2 - A potential biomarker for freshwater quality monitoring
AU - Ha, Mi Hee
AU - Choi, Jinhee
PY - 2009/8
Y1 - 2009/8
N2 - Daphnia hemoglobin (Hb) is one of the widely investigated invertebrate respiratory pigment. In this study, alteration of Daphnia magna Hb was evaluated in terms of its gene expression, using four D. magna Hb open reading frames (ORFs), by exposure of various chemicals, such as nonylphenol (NP), bisphenol A (BPA), benzo[a]pyrene (B[a]P), chloropyriphos (CP), paraquat dichloride (PQ), and lead nitrate (Pb), under laboratory conditions. A Daphnia reproduction test was also conducted to test the ecotoxicological relevance of chemical-induced Daphnia Hb gene expression. Daphnia Hb gene expression increased by most of tested chemicals. Nonylphenol induced all four Hb ORFs, and an increase in D. magna hemoglobin 2 (dmhb2), dmhb3, and dmhb4 gene expression was exposure concentration dependent. Although BPA and B[a]P also induced most of the Hb genes, the degree of increase was less than two-fold compared to the control. For CP and Pb exposure, an increase in dmhb2 and dmhb4 gene expression was the most significant among the four Daphnia Hb ORFs. Each ORF might exhibit different sensitivities to chemical stress; of the four ORFs studied, an increase in dmhb2 and dmhb4 gene expression was the most significant. It seems clear that Daphnia Hb has a considerable potential as a biomarker for freshwater toxicity monitoring, as an increase in Hb gene expression seems to be correlated with a decrease in reproduction in this animal. The results suggest that Daphnia Hb could give useful information to diagnose general health conditions in a freshwater ecosystem. Considering the potential of D. magna as a biomonitoring species and the physiological particularities of its respiratory pigments, Daphnia Hb could be developed as a biomarker for ecotoxicity monitoring.
AB - Daphnia hemoglobin (Hb) is one of the widely investigated invertebrate respiratory pigment. In this study, alteration of Daphnia magna Hb was evaluated in terms of its gene expression, using four D. magna Hb open reading frames (ORFs), by exposure of various chemicals, such as nonylphenol (NP), bisphenol A (BPA), benzo[a]pyrene (B[a]P), chloropyriphos (CP), paraquat dichloride (PQ), and lead nitrate (Pb), under laboratory conditions. A Daphnia reproduction test was also conducted to test the ecotoxicological relevance of chemical-induced Daphnia Hb gene expression. Daphnia Hb gene expression increased by most of tested chemicals. Nonylphenol induced all four Hb ORFs, and an increase in D. magna hemoglobin 2 (dmhb2), dmhb3, and dmhb4 gene expression was exposure concentration dependent. Although BPA and B[a]P also induced most of the Hb genes, the degree of increase was less than two-fold compared to the control. For CP and Pb exposure, an increase in dmhb2 and dmhb4 gene expression was the most significant among the four Daphnia Hb ORFs. Each ORF might exhibit different sensitivities to chemical stress; of the four ORFs studied, an increase in dmhb2 and dmhb4 gene expression was the most significant. It seems clear that Daphnia Hb has a considerable potential as a biomarker for freshwater toxicity monitoring, as an increase in Hb gene expression seems to be correlated with a decrease in reproduction in this animal. The results suggest that Daphnia Hb could give useful information to diagnose general health conditions in a freshwater ecosystem. Considering the potential of D. magna as a biomonitoring species and the physiological particularities of its respiratory pigments, Daphnia Hb could be developed as a biomarker for ecotoxicity monitoring.
UR - http://www.scopus.com/inward/record.url?scp=67651166623&partnerID=8YFLogxK
U2 - 10.1007/s00244-007-9079-0
DO - 10.1007/s00244-007-9079-0
M3 - Article
C2 - 19471991
AN - SCOPUS:67651166623
SN - 0090-4341
VL - 57
SP - 330
EP - 337
JO - Archives of Environmental Contamination and Toxicology
JF - Archives of Environmental Contamination and Toxicology
IS - 2
ER -