Transcriptome analysis reveals the effects of temperature on growth in tadpoles of spiny-bellied frog (Quasipaa boulengeri)

Quasipaa boulengeri is consumed as a valuable delicacy in many places in the world. Recent studies showed that water temperature is a very important environmental factor that influences the growth and metamorphosis of reared frog tadpoles. However, the molecular mechanisms of tadpoles in response to water temperature are still unknown. In this study, physiological changes and transcriptomes of tadpoles reared under different water temperatures were analyzed. The results showed that the body length, width, weight, and growth hormone content of tadpoles under 21°C were significantly higher than of those reared at 15°C or 27°C, indicating that frog tadpoles were highly sensitive to water temperature. Further comparative transcriptome analysis of these three groups of tadpoles identified a total of 2001 differentially expressed genes, which were predominantly related to energy metabolism and growth revealed by GO and KEGG enrichment. Importantly, in the GH/IGF signaling pathway, several key genes, including PI3K , ERK1/2 , and AMPK , were expressed significantly differently among the three groups, and the expression levels coincided with the changes of phenotype and hormone level. Together, our study provided a suitable rearing temperature (21°C) for tadpoles and contributed to the knowledge of molecular mechanisms underlying tadpoles in response to rearing temperature.