The response to temperature increase of Andiperla

Abstract

The entire life cycle of Andiperla occurs in ponds and streams within the glaciers of Patagonia at temperatures near 0°C. Unlike other water environments, the temperature of the ice-water mixture in the glaciers remains constant, regardless of the air temperature or season. In a series of 16 independent experiments, we assessed the temperature tolerance of A. morenensis larvae from the Perito Moreno glacier in comparison to other plecopterans from Patagonia, such as Notoperla spp. and Klapopteryx kuscheli, which inhabit streams outside the glaciers. The results showed that the critical thermal maximum (CTM) for A. morenensis was 20.0°C, while Notoperla spp. exhibited a CTM of 25.1°C, and Klapopteryx kuscheli had a CTM of 30.5°C. This suggests that Andiperla has remarkable temperature tolerance, but insects living in water with higher and variable temperatures show increased tolerance. To understand the genetic networks involved in the response to temperature increase in A. morenensis, we conducted RNA sequencing from individual larvae at their CTM and control larvae at 4°C. Analysis of the transcriptome of larvae and adults at 4°C revealed 44 transcripts encoding heat shock proteins, indicating a basal expression level. However, the insects at the CTM showed approximately 16,000 transcripts with altered expression levels compared to the control. Specifically, transcripts encoding Hsp83, Hsp71, and Hsp60A were upregulated, while those of Hsp70, Hsp90, and Hsp105 were downregulated. Additionally, we observed the upregulation of transcripts encoding proteins that modulate the level of juvenile hormone, such as JH esterase, JH epoxide hydrolase 1, and the short neuropeptide F.