Seahorses epitomize the exuberance of evolution. They have the unique characteristic of male pregnancy, which includes the carrying of many embryos in a brood pouch that incubates and nourishes the embryos, similar to the mammalian placenta. The male pregnancy of seahorses is unique, but their reproductive response to environmental disturbances has not yet been clarified. Tributyltin (TBT) is known to have an endocrine disrupting effect on the reproductive system of coastal marine organisms.
Recently, researchers led by Prof. LIN Qiang from the South China Sea Institute of Oceanology (SCSIO) of the Chinese Academy of Sciences evaluated the potential effects of exposure to environmentally relevant concentrations of TBT on the development of gonads and brood pouch of the lined seahorse (Hippocampus erectus). This work was published in Journal of Hazardous Materials on December 16th, 2020.
Physiological, histological, and transcriptional analyses were conducted, and results showed that high levels of TBT bioaccumulation occurred in male and female seahorses. TBT led to ovarian follicular atresia and apoptosis with the elevation of androgen levels, accompanied by the induction of genes associated with lysosomes and autophagosomes. Comparative transcriptional analyses revealed the likely inhibition of spermatogenesis via the suppression of cyclic AMP and androgen synthesis. Notably, the transcriptional profiles showed that TBT potentially affects the immune system, angiogenesis, and embryo nourishment of the brood pouch, which indicates that it has negative effects on the male reproductive system of seahorses.
In summary, this study reveals that environmental levels of TBT have the potential to affect the reproductive efficiency of seahorses, possibly leading to a reduction in their populations in coastal environments.
Fig. Effects of tributyltin on gonad and brood pouch development of male pregnant lined seahorse (Hippocampus erectus) at environmentally relevant concentrations
Information: Tang, L., Liu, Y.L., Qin, G., Lin, Q., Zhang Y.H., Effects of tributyltin on gonad and brood pouch development of male pregnant lined seahorse (Hippocampus erectus) at environmentally relevant concentrations, Journal of Hazardous Materials (2020), doi: https://doi.org/10.1016/j.jhazmat.2020.124854.
https://authors.elsevier.com/sd/article/S0304-3894(20)32845-4
Contact
LIN Qiang
South China Sea Institute of Oceanology, Chinese Academy of Sciences
E-mail: linqiang@scsio.ac.cn
