Nasonia in Undergraduate Research and
Nasonia is a small insect that is ideal for undergraduate
research and teaching. It has a number of useful features, particularly
for the teaching of genetics, ecology, evolution, development and
behavior. First, Nasonia is very easy to rear and handle.
The insects are easily reared on commercially available fly pupae
(the hosts). Virgin females and males are easily collected in the
pupal stage (there is a 3 day time window for virgin collection).
Adults are "user friendly" and can be handled without the need for
anaesthetization. Nasonia has a short generation time (two
weeks), but can be stored under refrigeration for periods of time,
allowing for flexibility in experimental timing. Both visible mutants
and molecular markers are available for genetic mapping and instruction
Second, Nasonia has interesting and diverse biology.
It is a parasitoid insect that kills and lays its eggs upon the
pupae of various flies. Parasitic insects are widespread in nature
and play an important role in regulating populations of other insects.
As such, Nasonia can be used to teach basic principles of
ecology, including life-cycles, parasite-host interactions, food
webs and the role of natural enemies. A key feature of Nasonia
is its interesting form of sex determination called "haplodiploidy".
Males are haploid (have only one set of chromosomes) and develop
from fertilized eggs whereas females are diploid (two sets of chromosomes)
and develop from fertilized eggs. This feature is very useful for
a number of reasons. Among them are easy detection and mapping of
visible mutations to one of the five chromosomes present in haploid
males. Haplodiploidy also affords the insect the ability to control
the sex of its offspring (by controlling whether sperm fertilize
eggs), which it does in interesting (and entertaining) ways. Three
closely related species provide an abundance of molecular markers
for comparative genomic and evolutionary studies. Differences between
the species in behavior (e.g. courtship and mate preference), development
and morphology provide excellent instructional opportunities for
teaching the principles of evolution.
Finally, there are many opportunities for new discovery
in Nasonia. Even students in large undergraduate laboratories
can make new discoveries, something not easily done for the more
standard model organisms. For example, unlike Drosophila melanogaster,
students working with Nasonia can easily discover and map
new mutations previously unknown to science. Their work can contribute
to the base of genetic knowledge on this insect, which is emerging
as a model for comparative genetic studies. Students working with
Nasonia hybrids can contribute to original studies on the
genetic basis of behavioral, developmental or morphological differences
between the species while learning important genetic and evolutionary
principles. Some topics that students can conduct original research
1. Discovery and mapping of new visible mutations.
2. Mapping of molecular markers (polymorphisms)
3. Genetic investigations of species differences in courtship, development
4. Analysis of early and late developmental mutants
5. Behavioral studies of courtship, sex ratio variation
6. Genetic analysis of B chromosomes
7. Studies of associated microorganisms, including the "sonkiller"
bacterium and Wolbachia
8. Studies of sex ratio adaptations
9. Male aggression and territoriality
10. Comparative genomics Ñ e.g. sequence differences and similarities
between Nasonia and Drosophila.
11. Population genetics, such as mitochondrial variation, intraspecific
and interspecific variation in behavior, morphology, development.