Vitellogenin expression in wild cyprinid Petroleuciscus esfahani as a biomarker of endocrine disruption along the Zayandeh Roud River, Iran

Abstract

Aquatic environments are the ultimate sink for most of anthropogenic pollutants. The Zayandeh Roud River is the most important river in the central Iranian Plateau, supplying water to a large population. In order to determine the potential occurrence and in vivo effects of Endocrine Disrupting Chemicals (EDCs) with estrogenic or anti-androgenic properties we analyzed the wild populations of an extensively distributed endemic fish species, Petroleuciscus esfahani. For this purpose, specimens were caught from two sites upstream and two sites downstream of the expected major anthropogenic pollution sources. P. esfahani full-length cDNAs for vitellogenin (vtg), with 4177 base pairs (bp) encoding a 1339 amino acids (aa), and for β-actin (actb), with 1776 bp encoding a 375 aa, were amplified and cloned. Hepatic vtg mRNA expression levels were measured by quantitative real-time PCR. Condition factor, gonadosomatic index and sex ratio were calculated and compared with vtg expression. Gonad histology was performed to study the possible presence of intersex condition. Detection of vtg transcripts in male individuals from the two downstream sampling sites supports the hypothesis of exposure to EDCs in these regions. Higher vtg expression in male individuals, together with reduced gonad size and condition factor, in specimens from the site located downstream of the major steel mill plant suggest a major endocrine disruption in this area.

Reproductive Toxicity of 3,4-dichloroaniline (3,4-DCA) on Javanese Medaka (Oryziasjavanicus, Bleeker 1854)

“…The GSI of males and females exposed to the highest concentration (250 µg/L) was lower, which indicated a stress symptom. The decrease in GSI might be associated with endocrine-active substances [47,48]. Similarly, GSI was not affected in Javanese medaka exposed to estrone, an EDC [43].…”

Carp (Cyprinus carpio) lipovitellin is a highly stable phospholipoglycoprotein with the same immunogenicity as vitellogenin

“…However, males and juvenile fish can also synthesize Vtg if exposed to exogenous oestrogen or oestrogen mimics (Bjorkblom, Salste, Katsiadaki, Wiklund & Kronberg, 2008). Thus, elevated Vtg levels in males and juveniles have been proposed as an excellent biomarker for environmental oestrogens (Gilannejad et al, 2016;Vajda et al, 2011). To date, numerous methods mainly employing immunoassays based on purified Vtg and its antibody have been developed for the quantification of piscine Vtg (Garnayak, Mohanty, Rao, Sahoo & Sahoo, 2013;Maltais & Roy, 2009).…”

Differential effects of zinc exposure on male and female oysters (Crassostrea angulata) as revealed by label-free quantitative proteomics

“…Many studies have reported that Vtg also plays nonreproductive roles as an immune-related molecule that is associated with defense reactions and by participating in environmental stress responses by recognizing cell damage through membrane binding and improving cell oxidative stress tolerance [66][67][68]. As such, Vtg is a biomarker for environmental stress, particularly for endocrine-disrupting chemicals [69,70]. In the present study, Vtg translation was upregulated by approximately 20-fold in the gonads of female oysters exposed to 500 mg L À1 Zn for 30 d.…”