1022-7954/05/4105- © 2005 Pleiades Publishing, Inc.
Russian Journal of Genetics, Vol. 41, No. 5, 2005, pp. 490–494. Translated from Genetika, Vol. 41, No. 5, 2005, pp. 614–619.
Original Russian Text Copyright © 2005 by Volkova, Vorobjova.
Mating behavior is a complex physiological–bio-
chemical trait, which is an important component of ﬁt-
ness in most animals. Courtship rituals have been
described in detail for many species, but their genetics
is far from being understood. Various experimental
approaches revealed pleiotropic genes responsible for
implementation of the species-speciﬁc sexual behavior
program . These genes operate mainly in cells of the
nervous system. Their mutations alter the sexual behav-
Sexual behavior of
vides a very convenient model for investigation of the
effect of mutations on sexual behavior. The courtship
ritual of this species is known in detail [2, 3]. Moreover,
detailed chromosome maps are available, most genes
have been located, products of their expression have
been identiﬁed, and their functions are known [4, 5].
Mutations that affect sexual behavior are commonly
divided into the following three groups [2, 6].
(1) Mutations directly affecting courtship elements.
For example, males mutant for the
do not perform the courtship ritual with females, per-
form the ritual with other males, homozygous for this
mutation, and stimulate wild-type males to perform the
ritual [2, 6, 7].
(2) Neurological mutations, e.g.,
affect the demonstration of the courtship ritual speciﬁc
for a certain sex and neuron differentiation .
(3) Mutations for sex-deﬁning genes, e.g., dysfunc-
tion of the genes
). The result of such mutations is
that individuals with chromosome sets typical of
females are phenotypically males. Consequently, their
sexual behavior is characteristic of males [2, 6].
Individuals with such mutations demonstrate abnor-
mal sexual behavior, are sterile or less fertile [2, 6–9],
and also less adaptive.
However, the fact that a female and a male exchange
information of different modality (visual, audial, chem-
ical, and tactile) during courtship [10, 11] suggests that
morphological mutations (eye color, body color, wing
morphology, etc.) would also affect the sexual behavior
and other ﬁtness components.
MATERIALS AND METHODS
Experiments were performed with the following
strains from the collection kept at the Department of
Genetics and Cytology, Kharkiv National University.
) and Oregon (
) are wild-type
strains, which have passed through 57 inbreeding gen-
erations by the beginning of the experiment. Outbred
(1-00), yellow body;
(1-1.5), white-apricot eyes;
(2-13.0), dumpy wings;
(2-67.0), vestigial wings; and
brown eyes. For genetic analysis of behavioral traits,
strains contrasting in sexual behavior were used.
Strains and hybrids were kept in culture vessels with
a standard yeast medium at 23
C. Flies were sorted by
sex within 24 h after their emergence from the pupar-
ium. Only virgin ﬂies were used in the experiment. Nar-
cotization was done with diethyl ether.
Mating activity of males was estimated by the num-
ber of males involved in mating within one hour [12, 13].
Females and males were placed into a test chamber in
is the number of ﬂies.
The percentage of males that had mated during one
hour was recorded. Female sexual receptivity was esti-
mated in the same way except that females and males
were taken in the ratio
and the percentage
of females involved in mating within one hour was
Inheritance Features of Mating Behavior Components
and Their Significance for Fitness
N. E. Volkova and L. I. Vorobjova
Department of Genetics and Cytology, Karazin Kharkiv National University, Kharkiv, 61077 Ukraine;
e-mail: firstname.lastname@example.org, email@example.com
Received April 1, 2004
—Components of mating behavior of
mutant and wild-type strains were
studied with respect to ﬁtness. The magnitude of the effect of genotype on the male mating activity, female sex-
ual receptivity, fertility and viability was determined. Strong positive correlation was found between the male
mating activity and ﬁtness components. It was shown that mating of strains contrasting in sexual behavior fea-
tures can be accompanied by both heterosis and maternal effect. Inheritance coefﬁcients were determined for
sexual behavior components.