Table 1. Candidate genes selected from the literature search.

Apis mellifera	Bombus terrestris	Biological function
Chymotrypsin	Chymotrypsin-1-like (LOC100648122)	Upregulated in bumblebee non-reproductive workers (Pereboom et al., 2005)
Gemini	Upstream binding protein 1-like (LOC100650338)	Upregulated in honeybee reproductive workers (Jarosch et al., 2011)
Cabut	Zinc finger protein 691-like (LOC100642767)	Upregulated in honeybee non- reproductive workers (Cardoen et al., 2011)
Ecdysone 20 monooxygenase	Ecdysone 20 monooxygenase-like (LOC100649449)	Upregulated in honeybee reproductive workers (Cardoen et al., 2011)
Yolkless	Vitellogenin receptor-like (LOC100649042)	Upregulated in honeybee reproductive workers (Cardoen et al., 2011)
Epidermal growth factor receptor	Epidermal growth factor receptor like (LOC100645521)	Upregulation of EGFR initiates ovary activation in queenless honeybee workers (Formesyn et al., 2014)
Ribosomal Protein L26	Ribosomal Protein L26 like (LOC100648461)	Differentially expressed in honeybee reproductive and non-reproductive workers (Thompson et al., 2007)
Odorant receptor2	Or2 odorant receptor 2/Queen mandibular pheromone (QMP) co-receptor (LOC100631089)	Upregulated in honeybee sterile workers (Grozinger et al., 2007)
Dop3 D2-like dopamine receptor	D2 like dopamine receptor (LOC100644210)	Upregulated in honeybee non-reproductive workers (Vergoz, Lim & Oldroyd, 2012)
Megator	Megator TPR like nucleoprotein (LOC100645723)	Upregulated in honeybee reproductive workers (Cardoen et al., 2011)
Ecdysteroid regulated gene E93/Mblk-1 transcription factor	Mushroom body large-type Kenyon cell specific protein 1-like (LOC100645656)	Upregulated in honeybee reproductive workers (Cardoen et al., 2011)
Ecdysone inducible gene L2/ImpL2	Neural/ectodermal development factor IMP-L2-like (LOC100645498)	Upregulated in honeybee non-reproductive workers (Cardoen et al., 2011)

Notes.

NCBI gene IDs are in parentheses.