| I have three ideas for good
projects to do in the lab. You will work in small groups, and the members
of each group can decide which project that group will work on. If you'd
prefer to try a project of your own design rather than one of the suggested
projects, I'd be happy to discuss that possibility with you.
Note: You may sometimes have to work briefly in the lab during times
other than our normal lab meeting time!
Suggested Project #1 - Search for homologues of the Drosophila
melanogaster quick-to-court (qtc) behavioral gene in other
species
The quick-to-court (qtc) gene of Drosophila melanogaster
plays a key role in controlling the sexual behavior of male fruit flies.
qtc was disovered relatively recently, and little is known about its mechanism
of function. Discovery, isolation, and characterization of qtc homologues
in other species should provide valuable insights into the function of
this gene.
Goals of Project #1
1) determine whether or not various other species have genes homologous
to qtc.
2) Isolate qtc homologues from a number of these other species.
3) Sequence these qtc homolgues.
4) Compare the sequences of the qtc genes from Drosophila melanogaster
and the other species to try to learn about function.
Realistically, we can only hope to accomplish goal #1 this semester!
Suggested Project #2 - Complete molecular mapping of deletion mutations
in the FTZ-F1 gene of Drosophila melanogaster
Steroid hormones control gene expression, and a wide range of developmental
processes in higher organisms, including humans. The biological processes
controlled by steroid hormones include the development of secondary sex
characteristics, reproductive function, and dietary metabolism. Metamorphosis
in insects is directed by a single steroid hormone called ecdysone. By
examining the mechanisms whereby ecdysone regulates metamorphosis in the
fly, we hope to gain a better understanding of how steroid hormones control
developmental processes in general. In order to determine how ecdysone
controls the complex process of metamorphosis, we are studying the genes
that are regulated by ecdysone during Drosophila metamorphosis.
The FTZ-F1 gene encodes a nuclear hormone receptor superfamily
member that appears to play a central role in directing stage-specific
genetic and developmental responses triggered by ecdysone. Our work indicates
that FTZ-F1 mediates the ecdysone-response of a set of other regulatory
genes, enabling them to be induced by the hormone at the appropriate developmental
times. In directing the precise timing of target gene induction by ecdysone,
FTZ-F1 ensures that developmental events occur at the correct time,
and in the correct temporal order.
In order to examine the role of FTZ F1 in development, we are
performing a mutational analysis of the gene. We have generated deletion
mutations in FTZ-F1, and we need to characterize these deletions
at the molecular level to determine exactly what pieces of FTZ-F1
each deletion removes.
Goals of Project #2
1) Isolate genomic DNA from mutant and control genotype flies.
2) Via PCR, amplify specific pieces of the wild-type and deletion-mutant
alleles of the FTZ-F1 gene and label them to use as hybridization probes.
3) Electrophorese the PCR products, and analyze the band patterns to determine
the breakpoints of the deletions.
Suggested Project #3 - Use of RAPD Analysis to Determine Genetic Diversity
among Crayfish at Mount Holyoke College
The purpose of Suggested Project #3 is to determine the genetic diversity
of the Mount Holyoke College crayfish population in order to make a judgment
of its stability. The crayfish at Mount Holyoke exist in a stretch of
Stony Brook between Upper and Lower Lakes, and in a stretch just below
Lower Lake. Upstream from the location of these groups, water is drawn
from Stony Brook and used to irrigate the Orchards Golf Course. This affects
the water levels in Upper and Lower lakes, and the sections of Stony Brook
where the crayfish are found. Through an ongoing study of the genetic
diversity of the local crayfish population, a determination may be made
as to the effect of the water level change on the Stony Brook ecosystem
at Mount Holyoke College.
To gauge the genetic diversity of crayfish at Mount Holyoke College, and
to determine if there is one distinct population or two in the Stony Brook
system, a method of DNA analysis known as Random Amplified Polymorphic
DNA, or RAPD, can be utilized. RAPD is one way of doing a Polymerase Chain
Reaction, or PCR, which is a method of amplifying or copying specific
DNA fragments. The RAPD method allows the detection of genetic polymorphisms
in a population. These polymorphisms are used to determine the extent
of inbreeding and outbreeding in that population.
Preliminary results obtained over the past few years have shown a wide
variety of genotypes in the crayfish collected between Upper and Lower
lake. You may wish to continue to analyze Mount Holyoke crayfish.
Goals of Project #3
1) Isolate genomic DNA from crayfish collected from Stony Brook and stored
at -80°C.
2) Perform RAPD PCR analysis on the DNA using several different primers.
3) Analyze the PCR products by gel electrophoresis and compare banding
patterns in different individual crayfish.
4) Look for patterns in the data.
Each group will work on its own schedule, so some of you may get farther
along than others. Don't worry - you will be graded according to your
effort, NOT to your relative success. At the end of the semester, you
will be required give an oral presentation on your research project.
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