BRAIN AND BEHAVIOR: THE ROLE OF THE FRUITLESS GENE IN COMPLEX BEHAVIOR IN DROSOPHILA
Whitney HumphreyDr. Barbara TaylorHHMI Summer Program
RELEVANCE OF WORK Understanding of the interaction
between the central nervous system and behavior.
Neurological diseases in humans Sex Determination and Sexual
Orientation in flies
DROSOPHILA MELANOGASTER
Ideal model organisms for studying genetics Short generation time Many strains exists
SEX-SPECIFIC BEHAVIORAL DIFFERENCES IN DROSOPHILA
Courtship Aggression
MALE VS. FEMALE GENETICSIn females, a cascade is initiated and through splicing events produce a female-specific transcript encoding a female-specific protein:
-DoublesexF (DsxF)
In males, a cascade is initiated but different splicing events produce male-specific transcripts encoding male-specific proteins:
-FruitlessM (FruM)-DoublesexM (DsxM)
IN FRU MUTANTS, MALE BEHAVIOR IS ALTERED
Expected behavior:-Males court females-Production of song-Copulation
Unexpected behavior:-Female-male courtship interrupted-Male-male courtship observed-This event is referred to as chaining.-May or may not be song but copulation does not occur
Deficiencies Fru3, Fru4
(P-element inserts)
Fru1
(Inversion)
AVERAGE ACTIVITY LEVELS FOR CANTONS FLIES
DL Cycle: 12-hours lights on, 12-hours lights off
Males: Anticipate lights on and have very little activity during the day (siesta)
Females: Do not anticipate lights on and do not take a siesta.
THE DROSOPHILA ACTIVITY MONITOR
How we measure activity:
The DL cycle:9:00 - 20:59 – Lights on21:00 - 8:59 – Lights off
ACTIVITY OF WILDTYPE MALES
9:0010:
1511:
3012:
4514:
0015:
1516:
3017:
4519:
0020:
1521:
3022:
45 0:00
1:15
2:30
3:45
5:00
6:15
7:30
8:45
0
10
20
30
40
50
60 CSA Average Activity vs. Time
Time
Aver
age
Coun
ts
Individual Raw Data
Lights on Lights off
n = 20
DO FRU HYPOMORPHS MALES HAVE WILDTYPE ACTIVITY CYCLES?
9:0011:
0013:
0015:
0017:
0019:
0021:
0023:
00 1:00
3:00
5:00
7:00
9:00
0102030405060fru1 Average Activ-
ity vs. Time
Time
Aver
age
Activ
ity
9:0011:
3014:
0016:
3019:
0021:
30 0:00
2:30
5:00
7:30
0102030405060
CSA Average Activity vs. Time
Time
Aver
age
Coun
ts
9:0011:
0013:
0015:
0017:
0019:
0021:
0023:
00 1:00
3:00
5:00
7:00
9:00
0204060
fru4 to1 Average Activity
Time
Activ
ity
9:0010:
4512:
3014:
1516:
0017:
4519:
3021:
1523:
000:452:3
04:1
56:0
07:4
50
204060
fru4tocs Average Activity vs Time
Time
Activ
ity
n = 20
n = 10n = 10
FRUM NULL MUTANTS HAVE WILDTYPE ACTIVITY CYCLES
9:0010:
3012:
0013:
3015:
0016:
3018:
0019:
3021:
0022:
300:001:3
03:0
04:3
06:0
07:3
09:0
00
102030405060
fru440 x frusat15 Av-erage Activity
TimeAc
tivity
9:0010:
3012:
0013:
3015:
0016:
3018:
0019:
3021:
0022:
300:001:3
03:0
04:3
06:0
07:3
09:0
00
102030405060
fru440 x P14 Average Activity
Time
Activ
ity
n = 12n = 12
CIRCADIAN RHYTHM A roughly-24-hour cycle in the
biochemical, physiological or behavioral processes.
CSA
Fru440 x Frusat15
CONCLUSION Initially, we investigated if mutations in
fruitless affected the male pattern of activity in flies.
We conclude that fruitless does not affect sex-specific activity cycles. However, fruitless mutants show levels of
decreased activity. We also discovered that the fruitless mutants
with deficiencies did not have a 24-hour period.
ACKNOWLEDGMENTS Dr. Barbara Taylor Dr. Jaga Giebultowicz Will Gibson Eileen Chow Dr. Kevin Ahern HHMI Summer Undergraduate Research
Program