Spontaneous rate of clonal mutations inDaphnia galeata

Abstract

Mutations are the ultimate source of heritable variation and therefore the fuel for evolution, but direct estimates exist only for few species. We estimated the spontaneous nucleotide mutation rate among clonal generations in the waterflea Daphnia galeata with a short term mutation accumulation approach. Individuals from eighteen mutation accumulation lines over five generations were deep genome sequenced to count de novo mutations that were not present in a pool of F1 individuals, representing the parental genotype. We identified 12 new nucleotide mutations in 90 clonal generational passages. This resulted in an estimated haploid mutation rate of 0.745 x 10-9 (95% c.f. 0.39 x 10-9 − 1.26 x 10-9), which is slightly lower than recent estimates for other Daphnia species. We discuss the implications for the population genetics of Cladocerans.

Temperature-dependence of spontaneous mutation rates

“…Mutation has been described as the 'quantum force' of biology 1 : pervasive throughout the tree of life, fundamental basis of evolution and notoriously difficult to measure. Evidence for the variation of mutation rates (µ) has been accumulating for a century, with pioneering investigations in Drosophila dating back to the 1930s 2,3 and more recent studies estimating the variability of µ in microorganisms [4][5][6] , plants [7][8][9] , invertebrates [10][11][12][13][14] as well as vertebrates [15][16][17] . On the intraspecific level, the spontaneous µ was often claimed to be a species-specific constant 18 .…”

Temperature dependence of spontaneous mutation rates

“…Mutation has been described as the “quantum force” of biology ( Gibson 2005 ): pervasive throughout the tree of life, the fundamental basis of evolution, and notoriously difficult to measure. Evidence for the variation of mutation rates (µ) has been accumulating for a century, with pioneering investigations in Drosophila dating back to the 1930s ( Timofeeff-Ressovsky 1936 ; Demerec 1937 ) and more recent studies estimating the variability of µ in microorganisms ( Lee et al 2012 ; Dillon et al 2018 ; Ramiro et al 2020 ), plants ( Sutherland and Watkinson 1986 ; Wang et al 2019 ; Krasovec et al 2020 ), and invertebrates ( Thomas et al 2010 ; Matsuba et al 2013 ; Berger et al 2017 ; Flynn et al 2017 ; Pfenninger et al 2020 ), as well as vertebrates ( Hodgkinson and Eyre-Walker 2011 ; Carlson et al 2018 ; Thomas et al 2018 ). On the intraspecific level, the spontaneous µ was often claimed to be a species-specific constant ( Lynch 2010 ).…”