Reproductive gene expression in a coral reef fish exposed to increasing temperature across generations

Abstract

We explored the potential underlying mechanisms of improved reproduction in a coral reef fish when exposed to a step-wise increase in temperature across generations. Expression of reproductive genes revealed that gonadotropin receptor genes, Lhcgr and Fshr, in male gonads are associated with reproductive plasticity.

From gametogenesis to spawning: How climate‐driven warming affects teleost reproductive biology

“…Downstream of gnrh , down‐regulation of pituitary follicle stimulating hormone (Fsh) gene fshβ has been noted for some species (Elisio et al ., 2012; Pérez et al ., 2011; Veilleux et al ., 2018), though there are exceptions, such as T. trichopterus females maintained with reproductively active males (Levy et al ., 2011). Interestingly, S. salar reared at 22°C have higher levels of plasma Fsh relative to those at 14°C in the months preceding ovulation (Anderson, Swanson, et al ., 2012).…”

“…Although TGP has been studied from one generation to the next (Shama et al ., 2014; Thorn et al ., 2019) or after several generations in teleosts (Donelson et al ., 2012, 2016; Fuxjäger et al ., 2019; Loisel et al ., 2019; Ryu et al ., 2020; Veilleux et al ., 2018), few studies have investigated reproductive function and success. In the following sections, studies on G. aculeatus and A. polyacanthus will be discussed, as significant progress on understanding TGP in the context of reproductive function has been made for these species.…”

“…In the second species, A. polyacanthus , a similar experimental approach was used: a 1.5°C increase in two successive generations (stepwise increase, SWI) or a 3°C increase in the F1, followed by maintenance at the same temperature in the F2 (single transgenerational increase, STGI) (Donelson et al ., 2010, 2016; Ryu et al ., 2018, 2020; Veilleux et al ., 2018). Under SWI across generations, some reproductive traits were positively ( e.g ., breeding proportion and egg number) or negatively ( e.g ., clutch size) impacted (Donelson et al ., 2016).…”

“…Under SWI across generations, some reproductive traits were positively ( e.g ., breeding proportion and egg number) or negatively ( e.g ., clutch size) impacted (Donelson et al ., 2016). These impacts appear to be mediated by changes in gene expression, for example fshβ , lhr , fshr (Veilleux et al ., 2018). Although the STGI regime resulted in negative transgenerational response (inhibition of reproduction), reproductive inhibition was reversible and reproductive function was partially restored once individuals were maintained at a lower temperature (Donelson et al ., 2016).…”

“…(2016), more species‐specific work is needed on TGP, especially in species with ecological or fisheries importance, to better understand the biological mechanisms involved under climate change. In addition, TGP can be mediated by either paternal or maternal mechanisms at elevated temperature (Shama et al ., 2014; for review, see Donelson et al ., 2018; Veilleux et al ., 2018; Fuxjäger et al ., 2019), highlighting the importance of studying both sexes in the context of global warming. Finally, Donelson et al .…”