Conservation of biological processes associated with diapause across insect species
GO terms found to be associated with diapause in bumble bees (Bombus terrestris ) (Amsalem, E. et al., 2015), an oil-collecting bee Tetrapedia diversipes (Santos, P. K. F. et al., 2018), alfalfa leaf-cutting bees (Megachile rotundata ) (Yocum, G. D. et al., 2018), and across 11 insect species spanning Diptera, Lepidoptera, and Hymenoptera (Ragland, G. J. & Keep, E., 2017) were compiled from previous studies. We compared these terms with those associated with DEGs between summer and winter bees in our study. We found that one category from fat bodies, dendrite morphogenesis (GO:0048813), overlapped, and two categories, neurogenesis (GO:0022008) and morphogenesis of an epithelium (GO:0002009), from flight muscle tissues overlapped with previous studies.
Among genes related to dendrite morphogenesis, 31 were differentially regulated between winter and summer bees in the fat bodies, while 39 were differentially regulated in the flight muscles (though note that this was not a significantly enriched GO category in this tissue). In total, 49 genes associated with dendrite morphogenesis were differentially regulated across both tissues between winter and summer bees, including homologs of genes encoding TGF-beta signaling pathway components DAF-1, DAF-4, and DAF-8 (TGF-beta receptor type 1 [LOC550930 ], activin receptor type 2A [LOC412471 ], and mothers against decapentaplegic homolog 3 [LOC412601 ]).
Among genes related to neurogenesis, 3 were differentially regulated between winter and summer bees in the fat bodies, while 4 were differentially regulated in the flight muscles. In total, 6 genes associated with neurogenesis were differentially regulated across both tissues between winter and summer bees, including epidermal growth factor receptor-like [LOC100577393 ], histone-lysine N-methyltransferase E(z) [LOC552235 ], sn1-specific diacylglycerol lipase alpha [LOC413224 ], protein gooseberry-neuro-like [LOC411374 ], BTB/POZ domain-containing protein 6-B [LOC100578209 ], and putative glutathione-specific gamma-glutamylcyclotransferase 2 [LOC408369 ].
Lastly, 6 genes related to morphogenesis of an epithelium were differentially regulated between winter and summer bees in the fat bodies, while 5 were differentially regulated in the flight muscles. In total, 6 genes associated with morphogenesis of an epithelium were differentially regulated across both tissues between winter and summer bees, including epidermal growth factor receptor-like [LOC100577393 ], cyclin-dependent kinase 14 [LOC552617 ], radixin homolog 1 [LOC412799 ], mitochondrial electron transfer flavoprotein subunit alpha [LOC551710 ], and dystroglycan [LOC408826 ].