Effects of 17 beta-estradiol injection and red-spectrum light on eyestalk hormones and vitellogenesis of the ornamental cleaner shrimp Lysmata amboinensis (De Man, 1888) (Decapoda: Caridea: Lysmatidae)
JOURNAL OF CRUSTACEAN BIOLOGY
Authors: Choi, Ji Yong; Choi, Cheol Young; Jung, Min-Min
Abstract
We analyzed the effects of 17 beta-estradiol (E-2) injection and red light on the sexual maturation and vitellogenesis of the cleaner shrimp Lysmata amboinensis (De Man, 1888) by measuring the change of mRNA expression levels of eyestalk and vitellogenesis-related hormones induced by both factors. We examined the eyestalk crustacean hyperglycemic hormone (CHH) and vitellogenesis-inhibiting hormone (VIH) genes. The E-2 injection did not affect changes of eyestalk hormones. The red light, however, caused a significant increase (P < 0.05) of CHH promoting maturity and a significant decrease of VIH, which suppressed vitellogenesis. The vitellogenin receptor (VTG-R) and mRNA expression (in situ hybridization) also caused the E-2 injection and red-wavelength irradiation to induce synthesis of vitellogenin (VTG). Red-light-induced gonadal maturation, promoting hormone and VTG synthesis, but E-2 did not change the eyestalk hormone. Red-light irradiation could thus be used as a novel, maturity-promoting alternative method in the culture of the species, which is different from the eyestalk-ablation method that has so far been used.
Underlying mechanisms of reproductive toxicity caused by multigenerational exposure of 2, bromo-4, 6-dinitroaniline (BDNA) to Zebrafish (Danio rerio) at environmental relevant levels
AQUATIC TOXICOLOGY
Authors: Xie, Xianyi; Jin, Yaru; Ma, Zhiyuan; Tang, Song; Peng, Hui; Giesy, John P.; Liu, Hongling
Abstract
2-bromo-4, 6-dinitroaniline (BDNA) is a mutagenic aromatic amine involved in the production and degradation of Disperse blue 79, one of the most extensively used brominated azo dyes. In our previous study, a multi-generational exposure of BDNA (0.5, 5, 50 and 500 mu g/L) to zebrafish from F-0 adult to F-2 larvae including a recovery group in F-2 larvae was conducted. The effects on apical points observed in individuals and the long-term effects predicted on population were all related to reproduction. In this study, we performed molecular analysis to elucidate the underlying mechanisms of the reproductive toxicity of BDNA. In F-1 generation, measurement of vitellogenin and transcription levels of genes associated with hypothalamus-pituitary-gland (HPG) axis, estrogen receptor (ER) and androgen receptor (AR) were conducted. There was a decrease in VTG level in the blood of F-1 female fish and transcription of genes related to ER was more affected than that of genes related to AR. These results were consistent with adverse effects that sexual differentiation was biased towards males and fecundity was impaired in a concentration-dependent manner in adults of F-1 generation after 150 days exposure. In F-2 generation, global gene transcriptions of F-2 larvae were investigated. It was uncovered that processes related to apoptosis, development and DNA damage were strongly affected. Alterations to these biological pathways accounted for the irreversible parental influence on a significant decrease in hatchability and increase in abnormality of F-2 larvae. All evidence suggested that the multigenerational exposure of BDNA posed lasting effects transmitted from parents to offspring that persisted after exposure ceased.