Transcript Afternoon trained bees Morning trained bees

Appointment Keeping in Honey
Bees: Molecular Clocks
N. L. Naeger
University of Illinois, Urbana-Champaign
BeeSpace Workshop, 21 May 2009
What do bees have to do
with time and clocks?
What do bees have to do
with time and clocks?
Outline:
1. Bees can keep appointments
with flowers
2. Finding the molecular basis
3. Broad results
4. Two specific examples
Natural History
 Bees can learn to visit discreet resources
at specific times of day
 Many plants have circadian rhythm of
nectar, pollen, and scent production
– Plants have endogenous rhythm
 Bees exhibit floral constancy
– Odor, color, and shape
– Time
Linnaeus' flower clock
Ice Plant:
10:00am
Goat’s
beard:
3am
Cat’s Ear:
9:00am
Chicory:
4:30am
Hawkweed:
7:00am
Field
Thistle:
6:00am
Moore & Rankin (1983)
Time-training bees
– Time of day
– Time of training
– Active vs. inactive
Time of collection
cAM
Time of training
 Train a single colony to
visit different feeders at
different times of day
 Do this at a time of the
year when bees will
specialize on a single
good food source
 Collect during anticipation
 Analyze:
tAM
tPM
Active /
anticipating
Inactive
cPM
Inactive
Active /
anticipating
 Time of collection: many genes
– Circadian / rhythmic behavior
– Cytoskeleton / cell adhesion
– Fat metabolism
 Time of training: few genes
– Signaling / ion transport
– Vesicle / secretory pathways
 Active vs. not: many genes
–
–
–
–
Ribosome and translation
Cation transport
Synapse / nerve communication
Mitochondria / ATP
Clock genes are affected by training
Oxford Univ.
Clock genes are affected by training
It’s actually more
complicated than that…..
Image from Panda (2002)
Clock genes are affected by training
Oxford Univ.
Clock genes are affected by training
Morning trained bees exhibit
clock gene expression
patterns similar to bees freely
fed
Period mean
1.2
1
0.8
0.6
0.4
0.2
0
1
2
Morning
trained
bees
3
4
Afternoon
trained
bees
Clock genes are affected by training
Morning trained bees exhibit
clock gene expression
patterns similar to bees freely
fed
Period mean
1.2
1
0.8
0.6
0.4
0.2
0
1
2
Morning
trained
bees
3
4
Afternoon
trained
bees
Clock genes are affected by training
Period mean
1.2
Period
1
0.8
0.6
0.4
0.2
0
1
2
3
0.4
4
Cycle A
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
1
2
Morning
trained bees
3
4
Afternoon
trained bees
Reward Circuitry
 Dopamine and octopamine
receptors are upregulated in
anticipating bees
– Hypersensitization of the
reward system in the brain
 Previous studies suggest
links between reward and
circadian rhythms
– Addictive drugs can cause
clock shifts
– Reward seeking is often
circadian
Acknowledgments
 Gene Robinson
 Sandra
Rodriguez-Zas
 Darrell Moore
– Byron Van Nest
– Jennifer Johnson
– Sam Boyd
 BeeSpace