Drosophila behaviour

• short generation time • easy to maintain • 4 large chromosomes • cheap to maintain • easily identifiable markers (mutant phenotypes) • transposons

• access to mates • access to food • access to territory to gain mates and foot • maintain social hierarchy • defence against predation

When they excise from the genome, they sometimes remove pieces of the DNA, making a mutant gene. In about 90% perfect excision, in 10% they take out more. The big advantage of that: control and mutant are genetically identic; good to reduce background noise

egg/embryo - 1st instar larva - 2nd instar larva - 3rd instar larva - prepupa - pupa - adult

1) Rapid construction of transgenic models of human disease 2) Well established easy systems to drive kd/ko our over expression of gene expression in tissue or temporal specific patterns 3) able to rapidly identify modifier/bypass gene pathways via genetic screens for enhancers or suppressors of phenotypes 4) easy to culture cell lines - very-easy to dsRNA treat genes of interest 5) rapid determination of the molecular basis of disease mechanisms 6) rapid forward genetics - isolate mutants through transposons or chemical mutagenesis

10-12 days at RT

DNA insertions (mostly hypomorphic)

a DNA-dependent transposon (no RNA intermediate; genomic DNA at original insertion site) flanked by inverted repeats (IRs) transposase will cut out the transposon and insert it to another place in the genome

Insert an inverted repeat of your targeted gene after UAS –> when it is transcribed, it will form dsRNA –> this will lead to RNAi –> inhibition of protein expression, because mRNA of the targeted gene is destroyed

• • It’s an animal; can be used to study development, physiology, and behaviour - • over 100 years of genetics - • 70% of human “disease” genes have an homologue in Drosophila

most used nowadays • one fly with tissue specific promoter followed by GAL4 in p-element (i.e. flanked by IR) - • one fly with UAS (upstream activating sequence that is the GAL4 target) followed by transgene in p-element - • mate them - • the progeny will express the transgene in cells also expressing GAL4 –> GAL4 expression activates UAS and transgene is turned on

• -Add a plasmid carrying the transposon/detective p-element and a donor plasmid with your desired transgene and a marker flanked by IR into D. embryo before the germline forms - • Hope that your transgene wil jump into the fly genome, mediated by p-element - • screen/select for marker - • at the excision site, either repair using a sister choromatid/homologous chromosome containing a P-element –> transposon remains in original position OR repair of gap using a homologous chromosome lacking a P element –> transposon no longer at original position

• fast gene identification • flexible scale

• • obligate diploid - • sexually dimorphic gametes - • some genetic redundancy

• Small pieces of DNA that can move from one site in the genome to another - • All organisms have them (about 45% of our genome: transposon remnants) - • jumping genes, selfish DNA - • mechanism for evolutionary change

4

• no saturation • non-random (hotspots)

• • DNA-dependent (prokaryotes & eukaryotes; DNA intermediates) - • retroviruses (eukaryotes only, RNA intermediates) - • retrotransposons (eukaryotes only, RNA intermediates)

ignore mate attack flee

• virgin –> mate • mated –> ignore

• dominant –> flee • submissive –> attack or ignore • unknown –> attack

• female –> mate • male –> ignore or attack

• female –> ignore • male –> attack

• ocotopamine (noradrenaline) • dopamine • serotonin • NPF (NPY) • 11 cis-vaccenyl acetate (cVA)