Regional differences in thermal adaptation of a cold-water fish Rhynchocypris oxycephalus revealed by thermal tolerance and transcriptomic responses

Abstract

Understanding how populations adapt to different thermal environments is an important issue for biodiversity conservation in the context of recent global warming. To test the hypothesis that populations from southern region are more sensitive to climate change than northern region in cold-water species, we determined the thermal tolerance of two geographical populations of a cold-water fish, Rhynchocypris oxycephalus: the Hangzhou population from southern region and the Gaizhou population from northern region, then compared their transcriptomic responses between a control and a high temperature treatment. The results showed that the thermal tolerance range and thermal tolerance polygon area of Hangzhou population were narrower than the Gaizhou population, indicating populations from southern region were possibly more vulnerable. Further transcriptomic analysis revealed that the Gaizhou population expressed more temperature responding genes than the Hangzhou population (583 VS. 484), corresponding with their higher thermal tolerance, while some of these genes (e.g. heat shock protein) showed higher expression in the Hangzhou population under control condition, suggesting individuals from southern region possibly have already responded to the present higher environmental temperature pressure. Therefore, these results confirm the prediction that populations from southern region are more sensitive to global warming, and will be important for their future conservation.

Hyperthermic stress resistance of bumblebee males: test case of Belgian species

“…Since there are differences between males and other sex/castes in body size and physiology, further studies on queens and workers should be conducted to compare thermal sensitivity between castes in social bees. Local adaptation at a large spatial scale is also possible like it was demonstrated in other organisms (Schoville et al 2012;Yu et al 2018;Collier et al 2019). However, as suggested by our results, there is no significative relation between body size of males (ITD), collecting sites, and the corresponding THS recorded for the specimen.…”

Effects of increased temperature on arctic slimy sculpin Cottus cognatus is mediated by food availability: Implications for climate change

“…In contrast, other studies suggest northern populations are more tolerant of high temperatures (e.g. Gaitán‐Espitia et al., 2014; Yu et al., 2018), and even still, others have found no evidence for thermal adaptation among populations (reviewed in Elliot & Elliot, 2010). The climatic variability hypothesis (Levins, 1969; Stevens, 1989) predicts that individuals at higher latitudes have greater physiological plasticity, because they experience a broader range of temperature variation.…”

Transcriptome Analysis of Yamame (Oncorhynchus masou) in Normal Conditions after Heat Stress

“…Heat stress induces protein unfolding, which plays an important role in promoting protein refolding by stimulating HSFs to regulate HSPs, such as HSP70 and HSP90 [10]. Additionally, HSP70 and HSP90 are the primary sensors of misfolded proteins that facilitate protein folding and prevent protein aggregation during encounters with heat stress [7,18]. Pei et al [41] reported that HSP proteins partially returned to a normal level after a nine-week recovery from heat stress in rabbit testis.…”

“…Many studies have investigated the differentially expressed genes (DEGs) during the response to heat stress in fish; for instance, gene expression of Chinese minnow from the northern region showed greater thermal tolerance than the southern species [18], and the specific regulation patterns indicated a difference between imported rainbow trout and a local breeding strain [16,19]. The thermal-tolerant rainbow trout showed higher expression levels of HSPs than the low thermal-tolerant group under heat stress in fin and gill tissues [9,20].…”