Spontaneous circadian rhythms in a cold-adapted natural isolate of Aureobasidium pullulans

FRANCO D. L.; CANESA P.; BELLORA N; RISAU GUSMAN S; OLIVARES YANES C; PÉREZ-LARA R; LIBKIND D; LARRONDO L; MARPEGAN L

Valparaiso

Simposio; XIV Latin American Symposium on Chronobiology; 2017

Circadiansystems enable organisms to synchronize their physiology to daily and seasonalenvironmental changes relying on endogenous pacemakers that oscillate with aperiod close to 24 h even in the absence of external timing cues. Theoscillations are achieved by intracellular transcriptional/translationalfeedback loops thoroughly characterized for many organisms, but still little is known about the presence and characteristicsof circadian clocks in fungi other than Neurospora crassa. We sought tocharacterize the circadian system of a natural isolate of Aureobasidiumpullulans, a cold-adapted yeast bearing great biotechnologicalpotential. A.pullulans formed daily concentric rings that were synchronized by light/dark cycles andwere also formed in constant darkness with a period of 24.5 h. Moreover, theserhythms were temperature compensated, as evidenced by experiments conducted attemperatures as low as 10 °C. Finally, theexpression of clock-essential genes, frequency, white collar-1, white collar-2 and vividwas confirmed. Insummary, our results indicate the existence of a functional circadianclock in A. pullulans, capable of sustaining rhythms at very lowtemperatures and, based on the presence of conserved clock-gene homologues,suggest a molecular and functional relationship to well-described circadiansystems