1022-7954/03/3912- $25.00 © 2003
Russian Journal of Genetics, Vol. 39, No. 12, 2003, pp. 1438–1441. Translated from Genetika, Vol. 39, No. 12, 2003, pp. 1693–1697.
Original Russian Text Copyright © 2003 by Kashtanov, Lazebny, Gracheva.
The genetic determination of life span, developmen-
tal rate, and sexual maturation, i.e., the traits that deter-
mine important aspects of the life cycle, has long been
a focus of genetic research. Correlation between alloz-
yme heterozygosity and ﬁtness components has been
repeatedly demonstrated in various organisms, includ-
ing plants , vertebrates [2, 3], and invertebrates .
In Russia, Yu.P. Altukhov and N.V. Varnavskaya were
the ﬁrst to demonstrate the association between mul-
tilocus heterozygosity and the aforementioned traits 
in a study on populations of Paciﬁc salmons from the
Afterwards, Altukhov formu-
lated the fundamental law “determining the cause–
effect relationship of individual (species) multilocus
heterozygosity with the age of maturation and, via the
latter, with life span” [5, p. 915].
Thus, the correlation between heterozygosity and
ﬁtness is generally acknowledged [2, 6]. However,
some authors recently reported on the absence of asso-
ciation between heterozygosity and individual charac-
teristics of ﬁtness [7–10]. Moreover, many studies have
not been published because the researchers have found
only a weak, if any, association between heterozygosity
and ﬁtness .
Therefore, it is important to extend the range of ani-
mal and plant species tested for the association between
heterozygosity and ﬁtness.
Analysis of this association is obviously important
for studying human populations with respect to the
social and cultural control of the life cycle of
. This is also important in the case of farm
animals, because this relationship could be used in
L. is one of such species.
The biological characteristics of the sable make it an
interesting object of studies on the relationships
between different characteristics of reproduction. First,
this species is characterized by a long reproductive
period (12 years or even longer), which, under the con-
ditions of commercial breeding lasts until the end of
life. Second, sexual maturation in sables is retarded
compared to other farm and domestic animals .
Note that female sables kept in cages do not bear off-
spring every year during the reproduction period;
sometimes, they “miss pregnancy.”
We studied the association of allozyme heterozy-
gosity with the age of the ﬁrst reproduction (maturation
rate), life span, and other reproductive characteristics
(the number of missed pregnancies during the repro-
ductive period and the mean fertility), as well as the
association between the age of the ﬁrst reproduction
and all the aforementioned traits.
MATERIALS AND METHODS
The captive (kept in cages) sable population used in
this study originated from the animals that had been
caught in natural populations. By the moment of the
study, this population had been kept at the Pushkinskii
Fur Farm (Moscow oblast) for 50–70 years. This was
the ﬁrst population of this species to be ever kept in cap-
tivity . At the ﬁrst stage of breeding in this popula-
tion, females were selected for the highest fertility.
Afterwards, long-term selection for coat color began
because of the demand for darker fur: in natural popu-
lations, a light yellowish coat color is considerably
The following characteristics of the biology of
sables were determined during the period of the exist-
Fitness Characteristics and Allozyme Heterozygosity
in an Artificial Population of the Sable
S. N. Kashtanov
, O. E. Lazebny
, and S. V. Gracheva
Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia;
fax: (095)135-12-89; e-mail: firstname.lastname@example.org;
Afanas’ev Institute of Fur Farming and Rabbit Breeding, Moscow oblast, 140143 Russia
Received February 12, 2003
—Associations between some characteristics of ﬁtness (the age of the ﬁrst reproduction, life span, fer-
tility, and the number of missed pregnancies) and heterozygosity for some allozyme loci have been studied in
a population of the sable
L. kept in cages at a farm. Of all ﬁtness characteristic studied, a weak
correlation has only been found between heterozygosity and the age of the ﬁrst reproduction (maturation rate).
The age of the ﬁrst reproduction is positively associated with the life span and fertility. The results obtained are
discussed in terms of the relationship between the genetic variation of longevity and developmental rate and
prospects of their application to breeding practice.