things I don't understand (1-4)

Question 1

what are the 4 principles of door discrimination

Answer 1

1. approx 1000 odorant receptor genes dedicated to olfaction in mammals
2. each OSN expresses a single OR (which has a distinct odor ligand profile)
3. OSNs expressing the same receptor converge on the same glomerulus in the brain
4. each door is encoded combinatorial = one odor can activate multiple ORs and each OR can respond to multiple odors

Question 2

what percentage of ORNs co-expres

Answer 2

10-25%

Question 3

what is the receptor for sugar

Answer 3

GR5A

Question 4

what is the receptor for caffeine (bitter)

Answer 4

GR66A

Question 5

where do male flies perceive non-volatile pheremones

Answer 5

on the foreleg tarsi

Question 6

what cranial nerves innervate the taste buds

Answer 6

7, 9 and 10

Question 7

what is found in the walls of papilla

Answer 7

sensory cells with microvilli arranged in pit-like invaginations

Question 8

what is attracted to CO2

Answer 8

mosquitos

Question 9

where are internal sensilla found

Answer 9

in the pharyngeal portion of the proboscis

Question 10

what degrades period
how

Answer 10

double-time - by hyperphosphorylation and degradation by proteolysis

Question 11

how does light reach clock neurons

Answer 11

via photoreceptive organs containing rhodopsin (e.g ocelli and HB-eyelets)

Question 12

how many OBPs are currently known, where are they secreted from

Answer 12

52 currently known
secreted from support cells

Question 13

what does a mutation to OR67d cause in male flies

Answer 13

inadequate pheromone detection
= they court mated females and male flies

Question 14

describe the activity of DN1 neurons

Answer 14

in the evening, output of DN1 is weak in high light, but strongly increases in low light

Question 15

what is the function of PDF neurons

Answer 15

synchronise clock neurons in the absence of light

Question 16

what happens in flies with null alleles of clock and cycle

Answer 16

less overall sleep than wild-type flies

Question 17

describe the process of arousal in neurons

Answer 17

light activates I-VLN
this releases PDF onto S-VLNs that project onto ellipsoid bodies to increase motor activity

Question 18

how do neurons control sleep

Answer 18

GABAergic sleep promoting neurons inhibit the arousal of I-VLN and S-VLNs

Question 19

what does VLN stand for

Answer 19

ventral lateral neurons

Question 20

temperature cycles are able to entrain the clock under constant light or dark cycles, what does this mean

Answer 20

there is an override of the light dependent degradation of timeless

Question 21

describe the evidence suggesting temperature reception is a tissue-autonomous process

Answer 21

isolated body parts are able to perceive temperature unlike isolated brains

Question 22

what gene is implicated in temperature reception

Answer 22

norpA gene

Question 23

what happens to animals carrying mutated norpA

Answer 23

they are unable to synchronise to temperature cycles

Question 24

what other gene is said to be implicated in temperature reception

Answer 24

Nocte gene

Question 25

describe the Siffre study

Answer 25

in 1962, Siffre spent 6 months with no exposure to light his circadian rhythm remained consistent at 24 hours and 30 minutes supporting evidence for the fact that circadian rhythms free run under constant conditions

Question 26

what higher order brain centre perceives sex peptide

Answer 26

SOG

Question 27

what centre of the female brain responds to auditory information

Answer 27

antennal mechanosensory and motor cortex

Question 28

in which sex is sex lethal protein only produced

Answer 28

in females

Question 29

what does the absence of sex lethal protein in males mean

Answer 29

transformer mRNA is spliced in the default pattern

Question 30

what happens in Fruitless null male flies

Answer 30

phenotypically male but they cannot court

Question 31

where are the sex specific transcripts of Dsx and Fruitless produced

Answer 31

P1 promoter (KO of these promoters is lethal)

Question 32

what does command centre visual info project to? what happens next

Answer 32

P1 cluster of neurons - they activate descending neurons that project down to the ventral ganglia

Question 33

what is the evidence for sex peptide in making females unreceptive

Answer 33

virgin females injected with sex peptide become unreceptive to mating

Question 34

what have gynandromorph studies revealed about the male courtship

Answer 34

only a single region in the dorsal protocerebrum needs to be genetically male for the fly to sing (this region is rich in fruitless neurons)

Question 35

what OBP is used to detect female pheremones

Answer 35

OBP57d

Question 36

what receptor is involved in perceiving female pheromones (gustatorily)

Answer 36

GR32A

Question 37

what do mutations to GR32A mean

Answer 37

males show increased courtship towards males and mated females the wings simultaneously extend during the courtship ritual.