Skip to main content

Inferring deleterious-mutation parameters in natural daphnia populations


Deng and Lynch (1, 2) proposed to characterize deleterious genomic mutations from changes in the mean and genetic variance of fitness traits upon selfing in outcrossing populations. Such observations can be readily acquired in cyclical parthenogens. Selfing and life-table experiments were performed for two such Daphnia populations. A significant inbreeding depression and an increase of genetic variance for all traits analyzed were observed. Deng and Lynch’s (2) procedures were employed to estimate the genomic mutation rate (U), mean dominance coefficient \(\left( {\bar h} \right)\), mean selection coefficient \(\left( {\bar s} \right)\), and scaled genomic mutational variance (V m/Ve). On average, Û, \(\left( {\hat \bar h} \right)\), \(\left( {\hat \bar s} \right)\) and \(\frac{{\hat V_m }}{{V_e }}\) (^ indicates an estimate) are 0.84, 0.30, 0.14 and 4.6E-4 respectively. For the true values, the Û and \(\hat \bar h\) are lower bounds, and \(\hat \bar s\) and \(\frac{{\hat V_m }}{{V_e }}\) upper bounds.


  1. 1.

    Deng, H.-W., Lynch, M. 1996. Estimation of the genomic mutation parameters in natural populations. Genetics 144, 349–360.

    PubMed  CAS  Google Scholar 

  2. 2.

    Deng, H.-W., Lynch, M. 1997. Inbreeding depression and inferred deleterious-mutation parameters in Daphnia. Genetics 147, 147–155.

    PubMed  CAS  Google Scholar 

  3. 3.

    Muller, H.J. 1964. The relation of recombination to mutational advance. Mut. Res. 1 1–9.

    Google Scholar 

  4. 4.

    Kondrashov, A.S. 1985. Deleterious mutations as an evolutionary factor. II. Facultative apomixis and selfing. Genetics 111, 635–653.

    PubMed  CAS  Google Scholar 

  5. 5.

    Kondrashov, A.S. 1988. Deleterious mutations and the evolution of sexual reproduction. Nature 336, 435–440.

    PubMed  Article  CAS  Google Scholar 

  6. 6.

    Charlesworth, B. 1990. Mutation-selection balance and the evolutionary advantage of sex and recombination. Genet. Res. Camb. 55, 199–221.

    CAS  Google Scholar 

  7. 7.

    Charlesworth, D., Charlesworth, B. 1987. Inbreeding depression and its evolutionary consequences. Ann. Rev. Ecol. Syst. 18, 237–268.

    Article  Google Scholar 

  8. 8.

    Kirkpatrick, M., Ryan, M.J. 1991. The evolution of mating preferences and the paradox of the lek. Nature 350, 33–38.

    Article  Google Scholar 

  9. 9.

    Kondrashov, A.S., Crow, J.F. 1991. Haploidy or diploidy: which is better? Nature 351, 314–315.

    PubMed  Article  CAS  Google Scholar 

  10. 10.

    Lynch, M., Gabriel, W. 1990. Mutation load and the survival of small populations. Evolution 44, 11725–1737.

    Article  Google Scholar 

  11. 11.

    Lynch, M., Burger, R., Butcher, D., Gabriel, W. 1993. The mutation meltdown in small asexual population. J. Heredity 84, 339–344.

    CAS  Google Scholar 

  12. 12.

    Lynch, M., Conery, J., Burger, R. 1995. Mutation meltdowns in sexual populations. Evolution 49, 1067–1080.

    Article  Google Scholar 

  13. 13.

    Lynch, M., Conery, J., Burger, R. 1995. Mutation accumulation and the extinction of small populations. Amer. Nat. 146, 489–518.

    Article  Google Scholar 

  14. 14.

    Crow, J.F., Simmons, M.J. 1983. The mutation load in Drosophila. Vol. 3c pp. 1–35 in The genetics and biology of Drosophila edited by Ashburner, M., Carson, H. L., Thompson, J. N. Academic, London, NY.

    Google Scholar 

  15. 15.

    Crow, J.F. 1993. How much do we know about spontaneous human mutation rates? Environmental and Molecular Mutagenesis 21, 122–129.

    PubMed  Article  CAS  Google Scholar 

  16. 16.

    Bateman, A.J., 1959. The viability of near-normal irradiated chromosomes. Inter. J. Rad. Bio. 1, 170–180.

    Article  Google Scholar 

  17. 17.

    Mukai, T., Chigusa, S.I., Mettler, L.E., Crow, J.F. 1972. Mutation rate and dominance of genes affecting viability in Drosophila melanogaster. Genetics 72, 335–355.

    PubMed  CAS  Google Scholar 

  18. 18.

    Charlesworth, B., Charlesworth, D., Morgan, M.T. 1990. Genetic loads and estimates of mutation rates in highly inbred plant populations. Nature 347, 380–382.

    Article  Google Scholar 

  19. 19.

    Comstock, R.E., Robinson, H.F. 1948. The components of genetic variance in populations of biparental progenies and their use in estimating the average degree of dominance. Biometrics 4, 254–266.

    PubMed  Article  CAS  Google Scholar 

  20. 20.

    Hayman, B.I. 1954. The theory and analysis of diallel crosses. Genetics 39, 789–809.

    PubMed  CAS  Google Scholar 

  21. 21.

    Deng, H.-W. 1998. Estimating (over)dominance coefficient and discriminating dominance vs. overdominance as the genetic cause of heterosis. Genetics, in press.

  22. 22.

    Caballero, A., Keightley, P.D., Turelli, M. 1997. Average dominance for polygenes: Drawbacks of regression estimates. Genetics 147, 1487–1490.

    PubMed  CAS  Google Scholar 

  23. 23.

    Deng, H.-W., and Fu Y.-X. 1998. On the three methods for estimating deleterious genomic mutation parameters. Genetical Research, in press.

  24. 24.

    Perrot, V., Richerd, S., Valero, M. 1991. Transition from haploidy to diploidy. Nature 351, 315–317.

    PubMed  Article  CAS  Google Scholar 

  25. 25.

    Lande, R., 1994. Risk of population extinction from new deleterious mutations. Evolution 48, 1460–1469.

    Article  Google Scholar 

  26. 26.

    Deng, H.-W. 1998. Estimation of deleterious-mutation rate and effects in outcrossing populations. (Submitted to Genetics).

  27. 27.

    Morton, N.E., Crow, J.F., Muller, H.J. 1956. An estimate of the mutational damage in man from data on consanguineous marriages. Proc. Natl. Acad. Sci. USA 42, 855–863.

    PubMed  Article  CAS  Google Scholar 

  28. 28.

    Falconer, D.S., Mackay, T.S. 1996. Introduction to quantitative genetics. Longman, New York.

    Google Scholar 

  29. 29.

    Lynch, M. 1983. Ecological genetics of Daphnia arenata. Evolution 37, 358–347.

    Article  Google Scholar 

  30. 30.

    Lynch, M. 1983. The genetic structure of a cyclical parthenogen. Evolution 38, 186–203.

    Article  Google Scholar 

  31. 31.

    Hebert, P.D.N. 1987. Genetics of Daphnia. Memorie Instituto Italiano Di Idrobiologia 45, 439–460.

    Google Scholar 

  32. 32.

    Lynch, M. 1985. Spontaneous mutations for life-history characters in an obligate parthenogen. Evolution 39, 804–818.

    Article  Google Scholar 

  33. 33.

    Lynch, M., Deng, H.-W. 1994. Genetic slippage in response to sex. Amer. Natur. 144, 242–261.

    Article  Google Scholar 

  34. 34.

    Innes, D.J. 1989. Genetics of Daphnia obtusa: genetic load and linkage analysis in a cyclical parthenogen. J. of Heredity 80, 6–10.

    Google Scholar 

  35. 35.

    De Meester, L. 1993. Inbreeding and outbreeding depression in Daphnia. Oecologia 96, 80–84.

    Article  Google Scholar 

  36. 36.

    Deng, H.-W. 1995. Sexual reproduction in Daphnia: its control and genetic consequences. Ph. D. Thesis. University of Oregon.

  37. 37.

    Deng, H.-W. 1996. Environmental and genetic control of sexual reproduction in Daphnia. Heredity 76 449–458.

    Article  Google Scholar 

  38. 38.

    Deng, H.-W. 1997. Photoperiodic response of sexual reproduction in Daphnia arenata group is reversed in two distinct habitats. Limnology and Oceanography 42, 609–611.

    Article  Google Scholar 

  39. 39.

    Deng, H.-W., Lynch, M. 1996. Change of genetic architecture in response to sex. Genetics 143, 203–212.

    PubMed  CAS  Google Scholar 

  40. 40.

    Lynch, M., Ennis, R. 1983. Resource availability, maternal effects, and longevity in Daphnia. Exp. Gerontol. 18, 147–165.

    PubMed  Article  CAS  Google Scholar 

  41. 41.

    Brooks, J.L., 1957. The systematics of North American Daphnia. The Yale University Press, New Haven, Connecticut.

    Google Scholar 

  42. 42.

    Brandlova, J., Brandl, Z., Fernando, C.H. 1972. The cladocera of Ontario with remarks on some species and distribution. Canadian Journal of Zoology 50, 1373–1404.

    Article  Google Scholar 

  43. 43.

    Hebert, P.D.N., Ward, R.D., Weider, L.J. 1988. Clonal diversity patterns and breeding system variation in Daphnia arenata, an asexual-sexual complex. Evolution 42, 147–159.

    Article  Google Scholar 

  44. 44.

    Hebert, P.D.N., Beaton, M.J., Schwartz, S.S. 1989. Polyphyletic origin of asexuality in Daphnia arenata. I. Breeding system variation and levels of clonal diversity. Evolution 43, 1004–1015.

    Article  Google Scholar 

  45. 45.

    Lynch, L., Spitze, K., Crease, T. 1994. The distribution of life-history variation in the Daphnia-pulex complex. Evolution 43, 1724–1736.

    Article  Google Scholar 

  46. 46.

    Houle, D., Hoffmaster, D.K., Assimacopoulos, S., Charlesworth, B. 1992. The genomic mutation rate for fitness in Drosophila. Nature 359, 58–60.

    PubMed  Article  CAS  Google Scholar 

  47. 47.

    Keightley, P. D., 1994. The distribution of mutation effects on viability in Drosophila melanogaster. Genetics 138, 1315–1322.

    PubMed  CAS  Google Scholar 

  48. 48.

    Houle, D., 1989. Allozyme-associated heterosis in Drosophila melenogaster. Genetics 123, 789–801.

    PubMed  CAS  Google Scholar 

  49. 49.

    Houle, D., 1994. Adaptive distance and the genetic basis of heterosis. Evolution 48, 1410–1417.

    Article  Google Scholar 

  50. 50.

    Houle, D., Morikawa B., and Lynch M., 1996. Comparing mutational variabilities. Genetics 143, 1467–1483.

    PubMed  CAS  Google Scholar 

  51. 51.

    Charlesworth, B., and Hughes, K. A. 1999. The maintenance of genetic variation in life-history traits. In: Evolutionary Genetics from Molecules to Morphology, eds. R. S. Singh and C.B. Krimbas. Cambridge University Press, Cambridge, UK, in press.

  52. 52.

    Deng, H.-W., Fu Y.-X. and Lynch, M. 1998. Inferring the major genomic mode of dominance and overdominance. Genetica, in press.

  53. 53.

    Li, J.-L., Li, J. and Deng H.-W. In preparation. The effect of overdominance on characterizing deleterious-mutation rate and effects in large natural populations.

Download references

Author information



Corresponding author

Correspondence to Hong-Wen Deng.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Deng, H. Inferring deleterious-mutation parameters in natural daphnia populations. Biol Proced Online 1, 1–9 (1998).

Download citation


  • Clutch Size
  • Total Genetic Variance
  • Genomic Mutation
  • Biological Procedure
  • Selfed Progeny