1a. Objectives (from AD-416):
The objective of this cooperative research is to raise and manipulate M. rotundata females nesting in field cages so as to capture the bees while performing specific behaviors related to different behavioral and physiological states. Genetic analysis of bees collected in the different states will be performed to determine any differential gene expression between states. This study is part of a larger sociogenomic study for exploring the molecular evolution of sociality in Hymenoptera.
1b. Approach (from AD-416):
Megachile rotundata adults will be reared in the ARS laboratory. The adult bees will then be released into field cages where their nesting activities will be monitored and manipulated for obtaining bees of different behavioral and physiological states. Freezer-killed adults will be shipped/transported to University of Illinois where bees will be dissected and genetic analyses will be performed.
3. Progress Report:
This study is part of a larger socio-genomic study for exploring the molecular evolution of sociality in Hymenoptera. We evaluated the effect of larval diet on larval and adult gene expression, physiology and behavior by manipulating M. rotundata larval food provisions to. Physiological and genomic analysis of larvae and adults collected from different experiments are being performed at the ARS lab in Logan, UT, and at the University of Illinois. The collaborator reared M. rotundata at the ARS facility, and performed both laboratory and field-cage studies. The collaborator reared larvae on pollen provisions that had been manipulated in the lab, then monitored the behavior of bees when building nests in field cages. We also evaluated which females underwent diapause. The bees in the experiment were frozen and shipped to the University of Illinois to determine their physiological state, and for gene expression analyses. We determined that larval nutrition affected the proportion of larvae that entered diapause, in particular, when normal larval provisions were supplemented with honey bee royal jelly, the proportion increased. We also found that some of the genes that are expressed differentially between larval honey bee queens and workers are also differentially expressed among M. rotundata larvae reared in different nutritional environments.