ISSN 1022-7954, Russian Journal of Genetics, 2009, Vol. 45, No. 4, pp. 423–429. © Pleiades Publishing, Inc., 2009.
Original Russian Text © S.Yu. Morozov-Leonov, S.V. Mezhzherin, O.D. Nekrasova, D.A. Shabanov, A.V. Korshunov, F.F. Krutyak, 2009, published in Genetika, 2009, Vol. 45,
No. 4, pp. 488–495.
The present study was focused on characteristics of
the mode of inheritance speciﬁc to hybrid frog
(Amphibia, Ranidae), which was made
based on quantitative analysis of the genotypes of
gametes produced by hybrid animals. Hybrid frog
is one of the well-known forms of hybrid
origin. This frog is characterized by unusual mode of
reproduction. The ﬁrst studies analyzing this phenome-
non, showed that
duced the gametes containing only the lake frog
genome (LR R) [1, 2]. Analogous mode of repro-
duction (called as hemiclonal) was earlier described in
interspeciﬁc ﬁsh hybrids of the genus
Thus, hybrid frog
can be reproduced
through backcrossing to that parental species, whose
genome is not inherited. However, more detailed anal-
ysis of the mode of inheritance speciﬁc to hybrid
frogs showed that it had some speciﬁc fea-
tures. First, in some parts of the species range, hybrid
form inherits exclusively of another parental species,
the pool frog (LR L) . Second, in some popula-
tions the hybrids produce more than one class of
gametes of different genotype and/or ploidity .
Finally, in many natural populations contain allotrip-
loids, which are not reproductively isolated from paren-
tal species . At the same time, alloploids of the genus
are characterized by gynogenetic repro-
duction . For these reasons, the mode of reproduc-
tion typical of hybrodogenetic frog
cannot be considered as hemiclonal in traditional inter-
pretation of this term.
In this study, quantitative analysis of the inheritance
of parental genomes by hybrid frog
MATERIALS AND METHODS
The data on gamete genotypes (shown
in Table 1) were taken from the literature and obtained
in the present study (for the methods, see below).
Determination of gamete genotypes
by means of electrophoretic analysis of germ cell sus-
pension (for males) or individuals eggs (for females).
Frogs were caught in 1992 through 2005. Standard
methods of sample preparation and electrophoresis
were used [4, 8].
Live animals were transported
to the laboratory, where they were anesthetized with
ethylic ether of 3-aminobenzoic acid and killed.
Gonads were removed. To examine mature egg mass
from the ovaries by means of electrophoresis, individ-
ual eggs were isolated under a binocular micrpscope
with the help of preparation needles. Then, the eggs
were separated from the tissue ﬂuid by placing on a
piece of ﬁlter paper for 10 to 20 s. After that, each egg
was placed into 1–2-ml tube. The tubes were added
with two to three drops of 10% sucrose solution stained
by addition of bromphenol blue. The tubes were closed
and frozen for 12 h. After thawing, each egg was
squashed in the tube, and the tubes were shacked sev-
eral times for more complete mixing of the egg content
with the sucrose solution. To analyze male germ cells,
testes were washed in distilled water, dried on ﬁlter
paper, and squashed between two slide plates.
Inheritance of Parental Genomes by a Hybrid
S. Yu. Morozov-Leonov
, S. V. Mezhzherin
, O. D. Nekrasova
, D. A. Shabanov
A. V. Korshunov
, and F. F. Krutyak
Schmalhausen Institute of Zoology, National Academy of Sciences of the Ukraine, Kiev, 01601 Ukraine;
Kharkov National University, Kharkov, 610077 Ukraine
Uzhgorod National University, Uzhgorod, 88000 Ukraine
Received July 10, 2007
—In this study, quantitative analysis of paternal genome inheritance by a hybrid form
Pall., 1881) (Amphibia, Ranidae) was examined. The
hybrid form examined was characterized by a polymodal mode of inheritance (genome of any of the parental
species can be inherited). The absence of correlation between the proportion of normal gametes and either sex
or ploidity of the producer was demonstrated. The gametes produced could be both haploid and diploid (hybrid
or homozygous). The mechanism of alloploid reproduction is discussed.