Arsenic impairs embryo development via down-regulating Dvr1 expression in zebrafish

Zebrafish as a Model for Developmental Neurotoxicity Assessment: The Application of the Zebrafish in Defining the Effects of Arsenic, Methylmercury, or Lead on Early Neurodevelopment

“…The results of this study showed a decrease in Dvr1 expression in 2 mM sodium arsenite treated embryos compared to those in the control group at 6 hpf in both of the experiments [191]. To further investigate the association between Dvr1 function and early development of the zebrafish nervous system, researchers injected a Dvr1 morpholino (MO) with or without plasmids encoding Dvr1 homolog (e.g., mouse GDF1) [191]. By performing this simple MO injection into the embryo, expression of a specific gene of interest can be silenced in the zebrafish.…”

“…In this study, quantitative polymerase chain reaction (qPCR) and whole mount in situ hybridization techniques were utilized to detect the levels of Dvr1 expression in the developing zebrafish. The results of this study showed a decrease in Dvr1 expression in 2 mM sodium arsenite treated embryos compared to those in the control group at 6 hpf in both of the experiments [191]. To further investigate the association between Dvr1 function and early development of the zebrafish nervous system, researchers injected a Dvr1 morpholino (MO) with or without plasmids encoding Dvr1 homolog (e.g., mouse GDF1) [191].…”

“…To generalize this assumption, however, additional investigations into the molecular mechanism of arsenite DNT need to be performed to clarify that the effects observed in the zebrafish are the consequences of DNT and not of teratogenicity. A follow-up study by Li et al [191] investigated the mechanisms of arsenic DNT with a focus on the activity of zebrafish Dvr1, which is involved in axis formation (known as growth differentiation factor 1 (GDF1) in mammals). In this study, quantitative polymerase chain reaction (qPCR) and whole mount in situ hybridization techniques were utilized to detect the levels of Dvr1 expression in the developing zebrafish.…”

“…By performing this simple MO injection into the embryo, expression of a specific gene of interest can be silenced in the zebrafish. The generated Dvr1 morphants were then subjected to α-AT staining at 48 hpf and showed impaired neural development in the brain, trunk, and tail compared to embryos in the control treatment (i.e., not genetically manipulated embryos) [191]. In the same immunostaining experiment using embryos co-treated with Dvr1 MO and plasmids, the expression of mouse GDF1 alleviated the neurodevelopmental effects of Dvr1 knockdown, suggesting the involvement of Dvr1 in the mechanism of arsenic DNT in the zebrafish [191].…”

Arsenic and human health effects: A review

“…A recent study with zebra fish animal model revealed that arsenic exposure impaired embryonic development through down regulation of Dvr1 expression, a key player in establishing left-right embryo asymmetry. It indicates arsenic induced embryo toxicity and its relationship with Dvr1(Li et al, 2012). But, only few studies have shown a direct relationship between arsenic exposure and reproductive health in human beings(Golub et al, 1998; Hopenhayn-Rich et al, 2000; Kwok et al, 2006).During the time of pregnancy, arsenic exposure (<50 µg/L) via drinking water affects uterus and placental growth results in progeny birth weight(Hopenhayn et al, 2003).…”