Hibernation with rhythmicity:the circadian clock and hormonal adaptations of the hibernating Asiatic toads(Bufo gargarizans)  

作　　者：Zhigang XIE Ibrahim M.AHMAD Lirong ZUO Feng XIAO Yongpeng WANG Dongming LI 

机构地区：[1]Zhejiang Academy of Agricultural Sciences,Hangzhou,China [2]College of Chemistry and Life Science,Zhejiang Normal University,Jinhua,China [3]Ministry of Education Key Laboratory of Molecular and Cellular Biology,Key Laboratory of Animal Physiology,Biochemistry and Molecular Biology of Hebei Province,College of Life Sciences,Hebei Normal University,Shijiazhuang,China

出　　处：《Integrative Zoology》2022年第4期656-669,共14页整合动物学（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(NSFC,31270457,30800129 to Z.X.),NSFC(31971413);the Natural Science Foundation of Hebei Province(NSFHB,C2020205038 to D.L).

摘　　要：Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rhythms of key hormones,melatonin(MT),corticosterone(CORT),triiodothyronine(T3),and thyroxine(T4),and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ectotherms.Here,a terrestrial hibernating species,Asiatic toad(Bufo gargarizans),was employed to investigate the plasma CORT,MT,T3,and T4;and the retina,brain,and liver mRNA expression of the core clock genes,including circadian locomotor output cycles kaput(Clock),brain and muscle ARNT-like 1(Bmal1),cryptochrome(Cry)1 and 2,and period(Per)1 and 2,at 7-time points over a 24-h period under acute cold(1 day at 4℃),and hibernation(45 days at 4℃).Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina,unlike the brain and liver.In contrast,during hibernation,the liver clock genes displayed significant circadian oscillations,while those in the retina and brain stopped ticking.Furthermore,plasma CORT expressed circadian oscillations in both groups,and T3 in acute cold exposure group,whereas T4 and MT did not.Our results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not,indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.

关 键 词：Asiatic toad circadian rhythm clock genes cold exposure HIBERNATION metabolic hormones 

分 类 号：Q958.117[生物学—动物学]