Biology Reference
In-Depth Information
ries. h is showed that they could respond to signals that initiate re-
productive activation. It is also likely that they were producing ecdys-
teroids and acting on the fat body, resulting in production of Vg.
Colin Brent, a former postdoc in my lab, showed that worker honey
bee ovaries produce ecdysteroids and that bigger ovaries produce
more. h is could be the mechanism linking ovaries to vitellogenin
and behavior.
We then set up a test to see whether the bees with extra ovaries
behaved dif erently. We implanted extra ovaries into 50 bees and im-
munologically inert glass beads of approximately the same weight
into an equal number of control bees. h e bees were placed in an ob-
servation hive, and my graduate student Adam Siegel watched them
as they passed through their behavioral changes, culminating in the
initiation of foraging. h e bees with ovary implants made the within-
hive behavioral transitions earlier and initiated foraging earlier in life
than the controls, as expected. We were unable to do a foraging be-
havior study because the surgical procedure was too demanding to
produce a sui cient number of bees. A sui cient statistical sample to
distinguish between groups of foragers usually requires several hun-
dred bees.
7.5.6 Verii cation of Genetic Architecture with
Africanized Honey Bees
Adam Siegel used bees from the European and Africanized bee back-
cross discussed in Section 6.6 and looked at the relationship between
foraging behavior and the number of ovarioles. He found a signii cant
relationship between the number of ovarioles and both the amount of
nectar collected and the sugar concentration of the nectar. In other
words, the size of the ovary was af ecting the perception of the nectar
reward. h is was a signii cant result because the bees for the mapping
study and the bees for the behavioral study came from the same
sources, and these sources were not derived from the high and low
strains. Hence he independently coni rmed the QTL, ovary, and behav-
ior relationships found in the selected strains.
