Journal
AQUATIC TOXICOLOGY
Volume 224, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.aquatox.2020.105503
Keywords
Tributyltin; Zebrafish; Spermatogenesis; Reproductive behavior; Gene expression
Categories
Funding
- Chongqing Research Program of Basic Research and Frontier Technology [cstc2016jcyjA0133]
- Scientific and Technological Research Program of Chongqing Municipal Education Commission [KJ1600308]
- Key laboratory of Freshwater Fish Reproduction and development (Ministry of Education, China), China [FFRD-2015-02]
- State Key Laboratory of Freshwater Ecology and Biotechnology, China [2019FB03]
Ask authors/readers for more resources
Tributyltin (TBT) was reported to affect sexual behavior and gametogenesis in fish. However, the modes of action involved are largely unclear. In order to elucidate the toxicological mechanisms of TBT in reproduction, zebrafish (Danio rerio) males were exposed to TBT at concentrations of 100 and 500 ng/L for 28 days. After exposure, the sperm count of the treated fish was sharply decreased though the testis weight and gonadosomatic index remained unchanged. Moreover, reduced number of spermatogonia and spermatozoa and increased spermatocytes were observed in TBT-treated fish by histological observation and PCNA-immunostaining. Increased number of apoptotic-positive spermatocytes was also present in TBT-treated fish, indicating an enhanced apoptosis in these cells. Consistent to decreased number of spermatogonia, down-regulated expressions of genes responsible for germ cell proliferation (cyclind1 and pcna) were observed in TBT-treated fish. In contrast, TBT elevated the expressions of genes involved in meiotic entry and maintenance (aldhla2, sycp3 and dmc1) while suppressed the mRNA level of gene responsible for terminus of meiotic entry (cyp26a1), in agreement with arrested meiosis and reduced sperm count. Furthermore, TBT significantly elevated the ratios of bax/bcl-2 and mfrsf1a/mftsf1b in testis, which are markers for intrinsic- and extrinsic-apoptotic pathways, consistent with the enhanced TUNEL positive signals in spermatocytes. Moreover, TBT also significantly affected the parameter of reproductive behaviors in treated fish (reflected by decreased frequency of meeting, visits and time spent in spawning area). Consistently, the expressions of genes responsible for the modulation of reproductive behaviors in brain (such as cyp19a1b, kiss2, gnrh3 and ompb) were significantly down-regulated in treated-fish. Interestingly, disrupted reproductive behaviors of untreated female fish were also observed in the present study. The present study indicated that TBT might affect the reproduction of zebrafish male by disrupting the spermatogenesis and reproductive behavior of the fish.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available