International Union for the Study of Social Insects (IUSSI2018), August 5-10, 2018 in Guarujá, Brazil.

only days left!
Find us: Ft

Gene expression and larval caste differentiation in social and socially parasitic bumble bees

Author(s):
David Henry Collins, David Henry Collins , Anders Wirén , Marjorie Labédan , Michael Smith , Irina Mohorianu , David Charles Prince , Tamas Dalmay , Andrew Frederick George Bourke
Institution(s):
University of East Anglia, Norwich, United Kingdom; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom ; University of East Anglia, Norwich, United Kingdom
Bumble bees (Bombus spp.) include eusocial species, i.e. species with queen and worker castes, and socially parasitic species that have secondarily lost the worker caste. To investigate the molecular basis of caste determination in eusocial insects, we used RNA-Seq to profile gene expression during female larval development in the eusocial B. terrestris and the socially parasitic B. vestalis. In B. terrestris, caste is determined when female larvae that are initially totipotent (i.e. that can develop into queens or workers) go through two critical phases in which their caste becomes fixed. In B. vestalis, female larvae were hypothesised to follow the same developmental trajectory as queen-destined larvae in eusocial Bombus. Our specific aims were twofold: 1) in B. terrestris, to isolate the genes associated with the critical phases of caste determination and compare them with other eusocial insects such as the honey bee Apis mellifera; and 2) in B. vestalis, to determine whether the loss of the worker caste is associated with the loss and/or silencing of worker-specific genes and whether gene expression during female larval development mirrors that of queen-destined B. terrestris larvae. We used RNA-Seq to isolate the genes critically associated with caste fate in B. terrestris and further investigated their expression patterns in B. vestalis. Preliminary results include the findings that genes associated with the Juvenile Hormone signalling pathway are strongly associated with queen determination in B. terrestris and that B. terrestris does not resemble A. mellifera in the molecular basis of caste determination. B. vestalis females’ gene expression profiles differed from those of both queen and worker-destined larvae in B. terrestris, suggesting that the evolution of social parasitism in Bombus involves more than the simple loss of the worker caste.
Back