Transcriptomic Changes in Hot Spring Frog Tadpoles (Buergeria otai) in Response to Heat Stress

Shohei Komaki,Jhan-Wei Lin,Masatoshi Matsunami,Yen-Po Lin,Takeshi Igawa,Si-Min Lin,Yu Lee,Ko-Huan Lee

doi:10.3389/fevo.2021.706887

Abstract

Buergeria frog tadpoles exhibit high thermal tolerance and are occasionally found in water pools that temporarily exceed 40°C. With the aim of understanding how they can cope with the severe heat stress, we performed RNA-seq of three heat-treated (38°C) and three control (25°C) tadpoles and compared their transcriptomic profiles. We identified 382 differentially expressed transcripts. A protein-protein interaction (PPI) network analysis of these transcripts further identified hub proteins involved in protein degradation, stress granule assembly, and global suppression of DNA transcription and mRNA translation. Along with the avoidance behavior against high water temperature, these endurance mechanisms potentially support tadpoles to survive in high temperatures for short periods of time. Similar mechanisms may exist in many other amphibian species whose habitats are prone to high temperatures.

Highlights

In their natural environment, organisms face various environmental stressors such as ultraviolet light, low and high pH, osmotic pressure, freezing, and heat
Based on the log-likelihood ratio test q-value and log2 fold change thresholds from differential expression analyses, we found 147 and 235 significantly upregulated and downregulated transcripts in response to the heat stress, respectively (Figure 2 and Supplementary Table 2)
Knowledge-based analyses imply that our transcriptome analyses detected sets of genes with important functions in coping with the heat stress

Summary

Introduction

Organisms face various environmental stressors such as ultraviolet light, low and high pH, osmotic pressure, freezing, and heat. Organisms exhibit various responses to such stressors at multiple biological levels, including changes in morphology, physiology, behavior, and life history (Crespi et al, 2013; Wingfield, 2013; Gormally and Romero, 2020). Most of these responses are initially caused by intracellular regulations mediated by the neural and hormonal system (Mastrangelo et al, 2012; Crespi et al, 2013; Wingfield, 2013; Gormally and Romero, 2020). The survival and distribution of organisms are largely determined by temperature, whereby an appropriate response to thermal stress is essential for their survival

Methods

Results

Conclusion