1062-3604/01/3205- $25.00 © 2001
Russian Journal of Developmental Biology, Vol. 32, No. 5, 2001, pp. 298–303. Translated from Ontogenez, Vol. 32, No. 5, 2001, pp. 360–366.
Original Russian Text Copyright © 2001 by Recoubratsky, Grunina.
Induced diploid androgenesis is considered an
effective method for the reconstitution of the genotypes
of lost or disappearing ﬁsh species from the genetic
material of the native or cryoconserved sperm (Veprint-
sev and Rott, 1979; Penman
., 1996; Grunina and
Neyfakh, 1997). Keeping this mind, the enucleated
eggs of the most closely related species should be
inseminated with the sperm of reconstituted species,
and, then, duplication of the male chromosome set in
haploid embryos should be induced; i.e., diploid andro-
genetic hybrids should be obtained. Elimination of the
female chromosome set is usually achieved by irradia-
tion and diploidization of androgenetic haploids by
suppression of the ﬁrst cleavage division.
However, androgenetic hybrids are often nonviable
and die atin early developmental stages (May
., 1991; Myers
., 1995; Recou-
., 1998). Androgenetic hybrids may be non-
viable even if the species used to obtain them are sufﬁ-
ciently closely related, as was shown for intrageneric
hybrids in chars (May
., 1988), tilapias (Myers
., 1995), and sturgeon (Recoubratsky
When androgenetic hybrids are produced, the male
nucleus lands in the egg of another species. In this case,
the interaction between the foreign nucleus and the
cytoplasm is often disturbed (nucleocytoplasmic
incompatibility) (Neyfakh and Radzievskaya, 1967;
Neyfakh, 1974); this appears to be the main cause of
mortality in androgenetic hybrids (Grunina and Neyfakh,
1997). Only certain combinations of species may be com-
., 1998; Bercsényi
., 2001). Thus, the problem of overcoming
the nucleocytoplasmic incompatibility is essential for
the reconstitution of species via induced androgenesis.
We propose that nucleocytoplasmic incompatibility
can be overcome in the following manner.
If eggs from ﬁsh of species A are not available but
spermatozoa are, then the eggs of species B should be
True hybrids AB are obtained by inseminating eggs
B with spermatozoa A.
Hybrids AB are grown to sexual maturity, and fertile
females are selected.
Enucleated eggs of hybrid females AB and sperma-
tozoa A are used to obtain androgenetic hybrids. The
paternal nucleus A in the hybrid egg AB is surrounded
by the cytoplasm, in which half of the proteins are syn-
thesized on conspeciﬁc templates. In fact, this situation
shows just the opposite of what arises in usual hybrids.
Therefore, it can be expected that the androgenetic
hybrids obtained as described above will be viable.
In this paper, we describe the results of experimental
testing of our theory. The carp and the goldﬁsh were
chosen as the “reconstituted” species and egg-donor,
respectively. We have already shown that androgenetic
hybrids of goldﬁsh and carp are nonviable (Grunina
., 1991). By the beginning of experiment, the
mature females of hybrids between goldﬁsh and carp
were already available, and our work consisted of
inducing diploid androgenesis using the carp spermato-
zoa and hybrid eggs.
in Androgenetic Fish Hybrids Can Be Overcome
A. V. Recoubratsky
and A. S. Grunina
All-Russia Research Institute of Freshwater Fishery, Rybnoe, Moscow oblast, 141821 Russia
Kol’tsov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119991 Russia
Received January 12, 2000; in ﬁnal form, June 27, 2000
—Many androgenetic ﬁsh hybrids are nonviable due to the disturbed interaction between the foreign
nucleus and the cytoplasm. It has been proposed that this incompatibility can be overcome if eggs from inter-
speciﬁc hybrids and sperm from one of the parental species are used for diploid androgenesis. Indeed, the
androgenetic progeny obtained as a result of the insemination of the enucleated eggs of goldﬁsh and carp
hybrids by the carp spermatozoa proved to be viable and fertile. This approach may be used for reconstitution
of the genotypes of rare or disappearing ﬁsh species with the help of induced androgenesis, if their native or
cryoconserved sperm is available.
: androgenesis, androgenetic hybrids, nucleocytoplasmic incompatibility, conservation of biodiver-
sity, goldﬁsh, carp.