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Blue Plants
Sue Karcher, Purdue University
The
Blue Plant system provides investigative labs using transgenic plants. The
transgenic plants contain the uidA (gusA) reporter gene under the control
of various promoters that respond to different environmental or
developmental signals. Following induction of these environmental or
developmental signals, the gusA gene will respond by producing the enzyme
- glucuronidase (GUS). When the plant tissue is stained with the
chromogenic compound X-gluc, those tissues that produce GUS turn blue.
This system allows students to monitor both the physiological responses of
plants to these signals, as well as the induction of gene activity as
reflected by GUS activity. The GUS assay is highly visible, safe for the
undergraduate laboratory, easy to conduct, and relatively inexpensive.
Chlamydomonas
Mike Adams, Eastern Connecticut State University and Steve Daggett, Avila College
Chlamydomonas
is
a haploid single-celled biflagellate green alga that can reproduce both
sexually and asexually. It is photosynthetic and motile, and can be grown
very cheaply. There are hundreds of mutants available and a wide range of
undergraduate research projects and lab exercises in areas such as
genetics, cell biology, population biology, behavior and photosynthesis.
C-Fern
Leslie Hickok and Tom Warne, University of Tennessee
C-Fern
is a
specially derived strain of the tropical homosporous fern, Ceratopteris
richardii, offers a dynamic approach to teaching many basic aspects of
plant biology using hands-on and inquiry approaches. C-Fern
gametophytes develop rapidly and are easy to culture. All phases of
gametophyte growth and differentiation, fertilization and early embryo
development can be easily observed using low power microscopy. Extended
culture and observations of the sporophyte phase can also be carried out.
Large numbers of individuals can be cultured in a very small space,
allowing students to work with populations and to obtain large data sets
(e.g., growth rate, germination rate, population sex ratio) during a two
week culture period. A wide variety of mutant strains are available
ranging from striking visual types like polka dot to developmental mutants
and types resistant to environmental stresses from agents such as
herbicides and salt.
Fast Plants
Paul Williams, University of Wisconsin
Wisconsin
Fast Plants are rapid-cycling brassicas that are members of the cabbage
and mustard family (Cruciferea). They have been developed through 15 years
of selective breeding to be used by teachers, students, and scientists in
their classrooms and laboratories as living models for study. Fast Plants
have a life cycle of 35-40 days (seed to seed) and can be grown in the
classroom under continuous fluorescent light. The basic stock will grow to
be about 15 cm high at maturity. Fast Plants are available in a wide
variety of easily recognized phenotypes. Fast Plants can be used for
examining the expression and inheritance patterns for both discrete and
continuously variable traits. Students will engage in phenotypic linkage
mapping of various traits of their choice selected from the Fast Plant
stock inventory. Data generated by students will serve as the basis for
the building of a phenotypic linkage map for Brassica rapa.
Freshwater Spring Organisms
Doug Glazier, Juniata College
This
research system has several advantages for investigations in ecology and
evolutionary biology, including: (1) field work can be carried out
year-round because many freshwater springs have nearly constant
temperatures, (2) spring ecosystems are fairly discrete and have
relatively few common species of animals, thus simplifying ecological
analysis, (3) springs may differ considerably in habitat, water chemistry
and biotic composition even within a local region, thus offering useful
"natural experiments", (4) the animals of springs are easy to
collect and maintain in the laboratory, and (5) brooding of the young and
year-round amplexus behavior in spring-dwelling amphipods and isopods make
these animals especially suitable for studying the ecology of reproduction
and sexual selection, an important evolutionary process. This system can
be used to perform a wide variety of field and laboratory experiments, to
make comparative studies at the levels of individuals, populations and
communities, and to estimate the evolutionary relationships of organisms
by using selected traits of a sample of spring-dwelling animal taxa.
Nasonia
Jack Werren, University of Rochester
Nasonia
is a small parasitic insect with features that make it an excellent
organism for undergraduate research and teaching, particularly for
genetics, evolution and ecology. A key features of Nasonia is ease
of rearing and handling. Nasonia has a short generation time (14
days at 250 C) and can be easily cultured on commercially available fly
hosts. Males and females can be readily sexed in the pupal stage (over a
three day time period) and stored under refrigeration until needed.
Adults are "friendly" and can be handled without
anesthetization. This makes virgin collection and genetic crossing
easy. Nasonia has haplodiploid sex determination; males are haploid and
derived from unfertilized eggs whereas females are diploid and derived
from fertilized eggs. This is useful feature for teaching basic genetic
principles. A number of visible mutants and molecular markers are
available for teaching linkage, epistasis and complementation.
Three closely related species with interesting behavioral and
morphological differences provide excellent opportunities for teaching
principles of evolution, including reproductive isolation, speciation and
adaptation.
Sea Anemone
Drew Ferrier, Hood College
Aiptasia
pallida, is a marine invertebrate that can be obtained from biological
supply houses and maintained in small culture dishes of seawater at room
temperature with artificial or natural light. A. pallida is unique among
algal-invertebrate symbioses in that the host and symbiont (algae) can be
separated experimentally and maintained separately for long periods of
time. This experimental system can be used to study the overall metabolism
of the symbiosis and the energy-producing and energy-consuming processes
within the sea anemone and its symbionts. Variables such as age, size,
reproductive condition, hormonal balance, degree of environmental stress,
nutritional condition, time of day, species or oxygen availability can be
manipulated for their effects on the symbiotic relationship.
Tobacco Hornworm
Sarah Deel, Carleton College and Amy Mulnix, Earlham College
Manduca sexta, are ideal organisms for research because they
are inexpensive, easily maintained, and complete their life cycle in a
semester. Students are able to investigate the effects of elevated carbon
dioxide levels on herbiovory, taking into account both consumption rates
and growth rates of hornworms. Students can research how Manduca sexta
larvae respond to feeding on tobacco plants grown in an enriched carbon
dioxide atmosphere. Developmental studies include tracking hornworms
through larval molts and metamorphosis into the adult hawk moth.
Trematodes
Ron Rosen, Berea College
Digenetic
trematodes are flatworm parasites that are responsible for a number of
disease conditions in humans; study of species which are non-human
pathogens provides students with safe models for an array of basic
investigations. This system will focus on the short-lived, aquatic
transfer stage known as the cercaria larva which serves as a link between
the snail intermediate host and the next host in the digenean's life
cycle.
Yeast
Beth Montelone, Kansas State University and Brian White, University of Massachusetts
The
simple eukaryote Saccharomyces cerevisiae (bakers' yeast) has many
advantages as a research system: small size, rapid growth, complete sexual
life cycle, safety, well-characterized genetics, a completely sequenced
genome, and not least, the world-wide community of yeast genetics
researchers as a resource base.
Zebrafish
Janice Chang, Massachusetts Institute of Technology
The embryos of the zebrafish are excellent for studying many aspects of
development because they are optically transparent and develop from
blastula to hatching in a few days. Students can observe developing
zebrafish from fertilized egg to mature adult using a dissecting
microscope. Zebrafish and breeding supplies are available from pet shops
at low cost. Students are able to research a variety of developmental
questions including the effect of teratogens such as retinoic acid on
zebrafish development.
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