Characteristics of the Allele Pool and the Genetic Differentiation of Goats of Different Breeds and their Wild Relatives by Str-Markers.

Based on 16 STR-loci, the allele pool and interbreed differentiation of goat breeds of Russian and foreign breeding were investigated in this study. These breeds included Karachai (KRCH-K, n=73, mountain zone; KRCH-Z, n=33, foothill zone), Dagestan Downy (DAGD, n=30), Dagestan Wool (DAGW, n=30), Soviet Wool (SOVW, n=30), Saanen (SAAN, n=34), Murciano-Granadina (MURS, n=37), as well as wild goats, represented by three species of mountain goats (n=52): Siberian Capricorn (Capra sibirica) of Altai (CSIB-S, n=6), Tajikistan (CSIB-T, n=4), Kyrgyzstan (CSIB-K, n=6), and the Himalayas (CSIB-H, n=4); Bezoar goat (Capa aegagrus) of Turkey (CAEG, n=3) and Pakistan (CAEG-S, n=3); West Caucasian tur (Capra caucasica): western Caucasian (Kuban, CCAU-K, n=10), central Caucasian (CCAU-M, n=8), and eastern Caucasian (Dagestan, CCAU-D, n=8). The highest genetic diversity was observed in the North Caucasus breeds, such as Karachai, Dagestan Downy, and Dagestan Wool. The mean numbers of alleles per locus and allelic diversity were 7.385-9.154 and 7.353-7.713, respectively. The genetic proximity of Caucasian breeds was confirmed by cluster analysis, and they formed a common branch with the highest genetic affinity, while the Orenburg and Soviet Wool breeds formed another branch, and the third branch with the least affinity was the dairy breed of foreign selection.The analysis of the phylogenetic tree of domestic and wild species established the formation of three clusters formed by the subspecies of the West Caucasian tur, Siberian ibex, and breeds of domestic goats. At the same time, populations of the Bezoar goats were localized at the root of the last cluster, which confirmed their role as the ancestors of domestic goats.

[The effect of artificial selection for coat color on fitness in a farm population of the sable (Martes zibellina)].

The relationship between the response to artificial selection for darker coat color and fitness in a farm population of the sable (Martes zibellina L.) from the Pushkinskoe Fur Farm (Moscow oblast) was studied. The selection was performed during 41 years. By the moment of the study, a response to the selection for this character had been obtained: the coat color in the selected population had become darker, and the proportion of black animals in it increased. In addition, sables with black heads, which were absent in the original population, had appeared. Artificial selection was accompanied by a decrease in the fitness of the selected population, which was expressed in decreased female reproductive capacity parameters (the fertility, maturation rate, and duration of the reproductive period). A selection technique consisting in the use of only highly fertile animals in the selection originally made it possible to restore the fitness parameters to the initial level almost without a decrease in the dark shade of the fur. However, further selection led to a drastic decrease in fitness that could not be precluded by any selection method used. The possible ways to overcome this unfavorable effect of artificial selection are discussed.

[Analysis of secondary sex ratio in the fox (Vulpes vulpes L.)].

Secondary sex ratio and its variability in relation to some paratypic and genetic factors were studied in the silver fox by analysis of data obtained at the Pushkinskii fur farm (Moscow oblast) in 1980-1989. A total of 17285 whelps were examined. The mean proportion of males over the ten years of observation was 0.536+/-0.004. No effect of parent age or litter size on this proportion was found. Individual analysis of the progeny of a single parent revealed 44 males and 49 females showing significant deviations from the expected sex ratio (l male : 1 female). These results can be used for reconstruction of pedigrees whose progeny yields regular deviations from the expected sex ratio.

Inheritance of litter size at birth in farmed arctic foxes (Alopex lagopus, Canidae, Carnivora).

Natural populations of the arctic fox (Alopex lagopus, Canidae, Carnivora) differ drastically in their reproductive strategy. Coastal foxes, which depend on stable food resources, produce litters of moderate size. Inland foxes feed on small rodents, whose populations are characterized by cycling fluctuation. In the years with low food supply, inland fox populations have a very low rate of reproduction. In the years with high food supply, they undergo a population explosion. To gain insight into the genetic basis of the reproductive strategy of this species, we performed complex segregation analysis of the litter size in the extended pedigree of the farmed arctic foxes involving 20,665 interrelated animals. Complex segregation analysis was performed using a mixed model assuming that the trait was under control of a major gene and a large number of additive genetic and random factors. To check the significance of any major gene effect, we used Elston-Stewart transmission probability test. Our analysis demonstrated that the inheritance of this trait can be described within the frameworks of a major gene model with recessive control of low litter size. This model was also supported by the pattern of its familial segregation and by comparison of the distributions observed in the population and that expected under our model. We suggest that a system of balanced polymorphism for litter size in the farmed population might have been established in natural populations of arctic foxes as a result of adaptation to the drastic fluctuations in prey availability.

[Effect of the hereditary characteristics of male blue foxes Alopex lagopus L. on the sex ratio of their offspring].

Family analysis of a commercial population of the blue fox (the Pushkinskoe Breeding Fur Farm, Moscow oblast) with respect to secondary sex ratio has been performed. The offspring of each individual male or female involved in crossing between 1984 and 1988 was analyzed. The study of all families formed by every male and every female has made it possible to determine a group of "outstanding" fathers (23 out of 287 males), whose offspring was predominantly male (62.1% of the offspring were males, versus 53.9% in the total population). The results of subsequent detailed study on the pedigrees of male blue foxes in whose offspring the sex ratio significantly deviates from 1:1 indicate that this character is transmitted from fathers to sons without the deterioration of other commercially valuable characters. It is presumed that the significant deviation of sex ratio from 1:1 in the offspring of some male blue foxes is determined by genetic factors.

[A variation of secondary sex ratio in blue fox (Alopex lagopus L.)]. / Izmenchivost' vtorichnogo sootnosheniia polov u pestsa (Alopex lagopus L.).

The effects of several genotypic and paratypic factors on the secondary (at birth) sex ratio was analyzed in blue fox bred in captivity. In particular, variation of sex ratio was for the first time studied as dependent on sire's age (without considering dam's age), the ages of both sire and dam, and the lines of both parents. The initial data were obtained from the Pushkino breeding facility, Moscow oblast. In total, 15,396 puppies were analyzed. The frequency of males (P) in this population was 0.551 +/- 0.004 (confidence interval 0.543 << p << 0.559). Parents' ages and litter size had no effect on the proportion of males in the progeny. In one of the two blue fox subpopulations under study, dam's line proved to be associated with a significant departure of sex ratio to a higher proportion of males, suggesting the effect of genotypic factors on the variation of secondary sex ratio in blue fox.

[Statistical analysis of secondary sex ratio variation in sable Martes zibellina L]. / Statisticheskii analiz izmenchivosti vtorichnogo sootnosheniia polov u sobolia (Martes zibellina L.).

The secondary sex ratio in sable Martes zibellina L. maintained in captivity was estimated for the first time ever. The data obtained at the Pushkin pedigree breeding farm (Moscow oblast) in 1982 through 1987 were analyzed. In total, 1705 litters of 414 females were examined. The total frequency of male births (P) was 0.527 +/- 0.007; the 95%-confidence interval of p (the probability of birth of a male) was within the limits 0.513 << p << 0.541, and the deviation from the expected 1:1 ratio was statistically significant. No effect of parental age and litter size on the number of male progeny was found. This may indicate a small influence of the parental hormonal and immunological status on sex ratio, which was reported in many other mammal species including those related to sable. Apparently, there is an evolutionary mechanism underlying the stable excess of males in sable litters.