Fly Project Begins

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Fly Project Begins

Objectives:Organize groups - 4 members maximum

Start notebooks - Describe traits and strains, etc.

Understand traits and obtain needed flies - Purebreeding

Learn about handling flies - Feeding , AnesthetizingSexing, Virgin collectionSet up stock of each strain

For September 18, obtain 10 virgin females of each strain (wild type,

w sn m e).

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Inheritance in Drosophila melanogaster

Project

Investigate genes responsible for four traits: white vs. red eyes; miniature vs. normal wings;ebony vs. tan body color, singed vs. normal bristles

Determine:1) Number of genes involved2) If each gene is X-linked or autosomal 3) If the mutant or wild-type allele for each is

dominant4) If genes are linked or assorting

independently5) Map distances between all linked genes

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Wild-type Drosophila melanogaster

Red eyesLong wings‘Gray/ tan’ bodySmooth bristles

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Traits Studied

Miniature wings ( m )

Forked bristles ( f )Singed bristles (sn)

+

sn

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Traits Studied

Scarlet eyes (st)

White eyes (w)

wild type (+)

Brown eyes (bw)

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Traits Studied

Wild type (+) Yellow bodies (y) Ebony bodies (e)

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Crosses to be Performed

Reciprocal crosses:

strain A x strain B ; strain A x strain B

F1 x F1 crosses ( F1 female x F1 male ): If all X-linked or independently assorting

Testcrosses ( F1 female x strain A or strain B male ): Mapping

F1 x pure-breeding recessive

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Finding Information about Traits

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Reasons for Studying D. melanogaster

Small size

Short generation time (10 days - two weeks )

Easy maintenance

Number of well characterized traits 13,601 protein-encoding genes identifiedcomprehensive genetic mapgenome sequencedmany genes comparable to humans

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Viewing and Anesthetizing Flies

Binocular dissecting microscopesocular focus, zoom

Carbon dioxideanesthetizing needlesanesthetizing platformsTurn off CO2 before leaving lab

MITES!!! Wipe down everything with ethanol (70%)even when not working with

flies

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Fly Care and Maintenance

Feeding - Instant Drosophila MediumSterile vials and plugs

Transfer flies to new vials with new foodStocks - Every two weeksCrosses - Every 3-4 days, until larvae in

first vials

Incubator 24OC (Room temperature for now)

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Fly Management and Supply Cleaning

Morgue - unwanted adults -

Freezer - unwanted cultures with potential larvae -

Vial and Plug Washing - thawed vials rinsed with warm water,medium dissolved, brushed from vial,

plugs rinsed with warm water until clean,

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Sexing Flies

Male Female

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Sexing Flies

http://www.bio.ilstu.edu/Edwards/other/Sexing_Drosophila.shtml

Sex combs are only seen in males

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Sexing Flies

http://www.bio.ilstu.edu/Edwards/other/Sexing_Drosophila.shtml

Genital arch in males

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Sexing Flies

Male Female

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Life Cycle

Pupae Eggs

Larvae

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Life Cycle

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Virgin Collection

Adults emerge from pupal cases (eclose)Males not ready to mate for 8-10 hrFemales ready immediately

Clear Vials before 9 AM

Return within 8 hours

Separate males and females into separate vials

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Lab Supplies and Access

Main Lab

Tour of Fly Room

Key Pad - 3334

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Before Leaving Lab Tuesday

Everyone in group must know how to:

feed, transfer, anesthetize flies

distinguish mutant traits from wild type

collect virgins

Plan - who will find information about each trait;

times when each member will be in lab to clear, etc.

By September 18 - Make sure you have 10 virgin females from each strain and 10 males from each strain for reciprocal crosses, which will be set up in lab.

Fly Project Begins

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