+
ward
'
s
science
5100 West Henrietta Road • PO Box 92912 • Rochester, New York 14692-9012 • p: 800 962-2660 • wardsci.com
Once a female has copulated, she will store sperm until needed. She is able to "choose" when to
fertilize her eggs. For example, the offspring from a non-virgin female are usually 95% female and
5% male. This occurs because the female chooses to fertilize 95% of her eggs with the sperm she
has stored, resulting in diploid female offspring. The other 5% of her eggs remain unfertilized and
therefore develop as haploid males.
VI. Genetics of Nasonia
When performing experimental genetic crosses, be sure to keep careful records of all experiments,
giving dates of hosting, results of crosses, and comments about technique.
As an example, a virgin female wild type Nasonia is crossed with a male scarlet eye mutant Nasonia.
The dark eye of the wild type is a dominant trait and is represented by "D". The scarlet eye is recessive
and is represented by "d".
Since the F1 generation is the result of two homozygous strains of Nasonia, the wild type parent has
only one possible characteristic in the gametes, wild (D). The scarlet parent also has only one possible
type of gamete (d). The F1 generation can therefore be diagrammed as follows:
Note: The male Nasonia is haploid, so the chromosome carries only one allele for the scarlet-eye trait,
indicated by the "d" in the diagram. The "–" represents the missing chromosome in the haploid male. The
female Nasonia carries two alleles for the dark-eye trait, indicated by "D". When the male and female alleles
combine, they produce dark-eyed females ("Dd"). The female Nasonia is also able to produce dark-eyed
male offspring through parthenogenesis, represented by "D–".
Since the dark-eyed trait is dominant, all of the F1 Nasonia will appear to be of the wild type, even
though some are not homozygous strains.
A brief survey of methods for working with Nasonia is all that has been possible within the scope of
this manual. We carry a full line of activities using Nasonia, and we urge you to take advantage of these
activities, which will provide greater detail and a more in-depth look at the versatile Nasonia.
Scarlet-Eyed Male (P)
Wild-Type
Female
(P)
d –
Dd D– D
Dd D– D
© 2021 Ward' s Science. All rights reserved. Rev. 2021
