Transcript Finding Information about Traits

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 , Anesthetizing
Sexing, Virgin collection
Set 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 involved
2) If each gene is X-linked or autosomal
3) If the mutant or wild-type allele for each is dominant
4) If genes are linked or assorting independently
5) Map distances between all linked genes
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Wild-type Drosophila melanogaster
Red eyes
Long wings
‘Gray/ tan’ body
Smooth 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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Finding Information about Traits
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Finding Information about Traits
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Finding Information about Traits
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Finding Information about Traits
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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 identified
comprehensive genetic map
genome sequenced
many genes comparable to humans
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Viewing and Anesthetizing Flies
Binocular dissecting microscopes
ocular focus, zoom
Carbon dioxide
anesthetizing needles
anesthetizing platforms
Turn 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 Medium
Sterile vials and plugs
Transfer flies to new vials with new food
Stocks - Every two weeks
Crosses - 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
Sex combs are
only seen in
males
http://www.bio.ilstu.edu/Edwards/other/Sexing_Drosophila.shtml
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Sexing Flies
Genital arch in males
http://www.bio.ilstu.edu/Edwards/other/Sexing_Drosophila.shtml
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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 hr
Females 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.
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