Effects Of Hibernation On Intestinal Transcriptome In The Greater Horseshoe Bat(Rhinolophus Ferrumequinum)

Hibernation is a complex physiological response that helps animals adapt to extreme environmental conditions.During hibernation,animals endure a long period of low temperature and fasting that dramatically affect the gut.To date,no studies have been conducted to assess effects of hibernation on intestine transcriptome.In this study,we generated the first intestine transcriptome in hibernating mammals(the greater horseshoe bat,Rhinolophus ferrumequinum).By looking for genes that are differentially expressed between the two states,we explored the effect of hibernation on the function of the gut.Using two widely used methods(edgeR and DESeq2)and stringent cut-offs in determining differentially expressed genes(DEGs),we identified 78 DEGs related to functional changes of the gut during torpor relative to summer active state.There were 16 genes with high expression during hibernation and 62 genes with low expression(i.e.high expression during summer active state).A total of 521 GO terms were obtained by Gene Ontology enrichment analysis and five of them were significant by setting FDR <0.05.Three of them were related to immune function and the other two were related to extracellular region part and plasma diaphragm part,respectively.Our results confirmed a systemic suppression of immune function in torpor,whereas several aspects of innate immunity were maintained and even increased(six genes that were highly expressed during torpor and are associated with innate immunity are GPC1,ALOX15,CTSL,SMPDL3 A,CDH26,and PGD).In addition,this study revealed 5 upregulated DEGs encoding membrane cytoskeletal linking proteins(ALPK3,LAMB3,LAMC2,KRT19 and PLXNA2)that may preserve the gut integrity during torpor.This study identified two genes related to digestion(LCT and TCN2)were significantly upregulated during hibernation.By comparing the DEGs identified in this study with the ones identified previously in other tissues and other species using either RNA-Seq or proteomics approaches,we found that almost all of the DEGs identified in this study appeared in previous studies,which suggested that hibernating animals might use similar gene regulatory networks or pathways to adapt to hibernation.Our study provides novel insights into changes of gut function associated with adaptation to potential stressors during hibernation.