Biology Reference
In-Depth Information
more ovarioles than low-strain larvae regardless of the nurse bees rais-
ing them. However, when high-strain workers were raised in low-strain
colonies by low-strain nurses, they had more ovarioles than when they
were raised by nurses of their own strain. h is demonstrates that the
nurse module for development af ected ovary development and dif-
fered between the high and low strains (Figure 8.4).
8.2.3 Starvation Experiments
Because nutrition af ects JH titers throughout larval development, and
the JH titers during the fourth and early i t h instars are critical for
rescuing ovarioles from programmed cell death, we starved early i t h-
instar larvae. We were interested in the nutritional sensitivity of larvae
during dif erent stages of development in order to better understand
how nurse bees might control development. Ying Wang and Osman
Kat anoglu (unpublished data) removed combs with larvae from colo-
nies and placed them in an incubator for 6 hours. During this time they
were not fed. Control larvae continued to be fed by nurse bees. h e
frames with the larvae were then returned to the hive, where they com-
pleted development. h e 6 hours of “starvation” (6 hours out of a total
of 6 days of larval development) had a profound ef ect on ovary devel-
opment. Control bees had an average of about nine ovarioles while
starved bees had an average of about i ve, a reduction of nearly 50 per-
cent. h is suggests that the timing of food delivery to developing larvae
at this stage may be a mechanism whereby the nurse bees control
ovary development in developing larvae, part of the nurse bee module
(Figure 8.4).
8.3 Developmental Signatures of Colony-Level
Artii cial Selection
Worker honey bees are responsible for the dif erences in the pollen-
hoarding phenotypes between the high and low strains. Individual bees
develop from egg to adult. Even newly emerged adults show dif erences
in sensorimotor-system responses and in some key neurobiochemical,
