RESUMEN
The impact of progestins (i.e. synthetic forms of progesterone) on aquatic organisms has drawn increasing attention due to their widespread occurrence in the aquatic environments and potential effects on the endocrine system of fish. In this study, the effects of norethindrone (NET, a progestin) on the reproductive behavior, sex hormone production and transcriptional expressions were evaluated by exposing female zebrafish to NET at 0, 3.1, 36.2 and 398.6 ng L-1 for 60 days. Results showed that NET impaired the mating behaviors of female at 36.2 and 398.6 ng L-1 exhibited by males and increased the frequency of atretic follicular cells in the ovary exposed to NET at 398.6 ng L-1. As for sex hormones, plasma testosterone concentration in zebrafish increased, while estradiol concentration decreased. Up-regulation of genes (Npr, Mpra, Mprß, Fshß, Lß, Tshb, Nis and Dio2) was detected in the brain of fish exposed to NET at 398.6 ng L-1. The transcriptional levels of genes (Esr1, Vtg1, Ar, Cyp19a, Cyp11b and Ptgs2) were generally inhibited in the ovary of zebrafish by NET at 398.6 ng L-1. Moreover, the transcripts of genes (Vtg1, Esr1, Ar and Pgr) in the liver were reduced by NET at 36.2 and 398.6 ng L-1. Our findings suggest that NET can potentially diminish the of fish populations not only by damaging their reproductive organs, but also by altering their mating behavior through the changes in the expressions of genes responsible for the production of sex hormones.
Asunto(s)
Hormonas Esteroides Gonadales/sangre , Noretindrona/toxicidad , Ovario/efectos de los fármacos , Conducta Sexual Animal/efectos de los fármacos , Transcripción Genética/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Pez Cebra/fisiología , Animales , Sistema Endocrino/efectos de los fármacos , Femenino , Hormonas Esteroides Gonadales/genética , Masculino , Ovario/patología , Progesterona/metabolismo , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/metabolismoRESUMEN
Using a network approach, we estimate the output loss due to the lockdown of the Hubei province triggered by the coronavirus disease (COVID-19). Based on our most conservative estimate, China suffers about 4% loss of output from labor loss, and global output drops by 1% per period due to the economic contraction in China. About 40% of the impact is indirect, coming from spillovers through the supply chain inside and outside China. (JEL E23, E24, F62).