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Theoretical and Applied Genetics

, Volume 92, Issue 1, pp 109–115 | Cite as

Sex ratio in silver foxes: effects of domestication and the star gene

  • L. N. Trut
Article

Abstract

The course of changes in secondary sex ratio (proportion of males at birth) in silver foxes bred at the fur farm of this Institute was analyzed. Data collected over several years of breeding of a domesticated (experimental) population selected for amenability to domestication and of a commercial (control) were compared. A tendency to increase in secondary sex ratio was demonstrated in both populations. However, the proportion of males at birth was higher in domestic foxes. This proportion, calculated from the combined data for 1978–1993, was 0.538±0.005 and 0.511±0.007 in the selected and commercial populations, respectively. The minimal departure of the observed sex ratio from 0.5 was demonstrated for litters with five pups, which is close to the average litter size in fox populations. The proportion of males increases with both increasing and decreasing litter size. An analysis of secondary sex ratio with respect to maternal age revealed a minimal departure of sex ratio from the expected in offspring from foxes of optimal reproductive age (2–4 years). An effect of the autosomal semidominant coat color mutation star on male excess at birth was also found: secondary sex ratio was higher (0.583±0.015) in offspring of mothers heterozygous for the star mutation than from standard types of the domesticated population. The increase in secondary sex ratio in the analyzed fox populations is viewed as a correlated response to selection for domestication. The hormonal mechanisms mediating the effects of both this selection and the star mutation on sex ratio at birth are discussed.

Key words

Secondary sex ratio Zygotic selection Hormonal level Domestication Vulpes vulpes 

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References

  1. Bakken M (1995) Sex ratio variation and maternal investment in relation to social environment among farmed silver fox vixens (Vulpes vulpes) of high competition capacity. J Anim Breed (in press)Google Scholar
  2. Belyaev DK (1969) Domestication of animals. Science 5:47–52Google Scholar
  3. Belyaev DK (1979) Destabilizing selection as a factor in domestication. J Hered 70:301–308Google Scholar
  4. Belyaev DK, Trut LN (1964) Behavior and reproductive function in animals. I. Correlation between behavior and breeding season and fertility (in Russian). Bull Mosk Obsh Ispit Prirodi 69:5–19Google Scholar
  5. Belyaev DK, Trut LN (1982) Accelerating evolution. Sci USSR 5:24–29 60–64Google Scholar
  6. Belyaev DK, Ruvinsky AO, Trut LN (1981) Inherited activation-inactivation of the star gene in foxes. J Hered 72:264–274Google Scholar
  7. Belyaev DK, Plyusnina IZ, Trut LN (1984) Domestication in the silver fox (Vulpes fulvus Desm): changes in physiological boundaries of the sensitive period of primary socialization. Appl Anim Behav Sci 13:359–370Google Scholar
  8. Belyaev DK, Oskina IN, Trut LN (1988) Genetics and phenogenetics of the hormonal characteristics of the corticoid function of the adrenals in silver black foxes (in Russian). Genetika 24:715–722Google Scholar
  9. Bull JJ (1981) Sex ratio evolution when fitness varies. Heredity 46:9–26Google Scholar
  10. Clarke IJ, Hemsworth PH, Barnett IL, Tilbrook AJ (1992) Stress and reproduction in farm animals. Stress Reprod 86:239–252Google Scholar
  11. Clark MM, Karpluk P, Galef Jr BG (1993) Hormonally mediated inheritance of acquired characteristics in Mongolian gerbils. Nature 364:712Google Scholar
  12. Clutton-Brock TH, Jason GR (1986) Sex ratio in mammals. Q Rev Biol 61:339–374Google Scholar
  13. Clutton-Brock TH, Albon SD, Guinness FE (1985) Parental investment and sex differences in juvenile mortality in birds and mammals. Nature 313:131–133Google Scholar
  14. Evsikov VI (1987) Genetic and evolutionary aspects of the problem of mammalian fertility homeostasis (mink as a model) (in Russian). Genetika 23:988–1002Google Scholar
  15. Gray E, Hurt VK (1979) Distribution of sexes in cattle. J Hered 70:273–274Google Scholar
  16. Gray E, Katanbaf MN (1985) Sex ratio and distribution of sexes in swine. J Hered 76:36–38Google Scholar
  17. Howe H (1977) Sex ratio adjustment in the common grackle. Science 198:744–746Google Scholar
  18. Huck UW, Labov JB, Lisk PD (1987) Feed-restricting first generation juvenile female hamsters (Mesocricetus buratus) affects sex ratio and growth of third-generation offspring. Biol Reprod 37:612–617Google Scholar
  19. James WH (1989) Parental hormone level and mammalian sex ratios at birth. J Theor Biol 139:59–67Google Scholar
  20. James WH (1992) The hypothesized hormonal control of mammalian sex ratio at birth a second update. J Theor Biol 155:121–128Google Scholar
  21. Naumenko EV, Belyaev DK (1980) Neuroendocrine mechanisms in animal domestication. In: Altukhov YP (ed) Problems in general genetics. Proc 14th Int Cong Genet MIR, book 2. Moscow, pp 12–24Google Scholar
  22. Nishida SK, Otsuka J, Hayashi H (1976) Sex ratio of offspring in domestic animals: swine. Jpn J Anim Reprod 22:106Google Scholar
  23. Osadchuk LV, Trut LN (1989) Gonad endocrine function female silver foxes under selection for domestic behavior, (in Russian). J Obshch Biol 50:189–198Google Scholar
  24. Pratt N, Huck UW, Lisk RD (1989a) Do pregnant hamsters react to stress by producing fewer males? Anim Behav 37:155–158Google Scholar
  25. Pratt N, Huck UW, Lisk RD (1989b) Effects of social stress during early pregnancy on litter size and sex ratio in the golden hamster. J Reprod Fertil 87:763–769Google Scholar
  26. Price EO (1984) Behavioral aspects of animal domestication. Q Rev Biol 59:1–32Google Scholar
  27. Richter CP (1950) Domestication of the Norway rat and its implications for the stress problem. Proc Assoc Res Nerv Ment Dis 29:19–47Google Scholar
  28. Rokitsky PPh (1973) Biological statistics. Vischaya shkola 318Google Scholar
  29. Trivers RL, Willard DE (1973) Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90–92Google Scholar
  30. Trut LN (1980) Role of behavior in domestic transformation of animals. PhD thesis, Institute of Cytology and Genetics, NovosibirskGoogle Scholar
  31. Trut LN (1988) The variable rates of evolutionary transformations and their parallelism in terms of destabilizing selection. J Anim Breed Genet 105:81–90Google Scholar
  32. Trut LN (1991) Some genetic aspects of piebald spotting in silver foxes (Vulpes vulpes) and interrelation between the vector of selection and variability. In: Shumny VK, Ruvinsky AO (eds) Problems of genetics and theory of evolution (in Russian). Nauka, Novosibirsk, pp 67–84Google Scholar
  33. Zhelezova AI (1991) Influence of the star gene on potential fertility and embryonic death of silver foxes. In: Trut LN, Osadchuk LW, Borodin PM (eds) Evolutionary-genetics and genetic-physiological aspects of the fur animals domestication (in Russian). Institute of Cytology and Genetics, Novosibirsk, pp 171–183Google Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • L. N. Trut
    • 1
  1. 1.Institute of Cytology and Genetics of the Siberian Department of the Russian Academy of SciencesNovosibirskRussia

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