Differentiation of aphid clones using DNA fingerprints from individual aphids

An RNA derivative (pSPT 18.15) of Jeffreys' 33.15 human minisatellite core sequence was used to probe DNA from individuals of the peach-potato (Myzus persicae) and grain (Sitobion avenae) aphid. Sufficient and reproducible quantities of DNA (M. persicae = 0.90 $\pm $ 0.19 $\mu $g DNA individual$^{-1}$; S. avenae = 1.50 $\pm $ 0.30 $\mu $g DNA individual$^{-1}$) were extracted from individuals by whole-body homogenization to produce complex multi-locus DNA fingerprints. Profiles contained 19.5 $\pm $ 2.4 (M. persicae) and 14.8 $\pm $ 1.2 (S. avenae) fragments per individual, mainly within the 0.6-6.6 kb range, and exhibited marked endonuclease-specific variations in complexity. Individuals from six clones of S. avenae found to be monomorphic at 11 putative allozymic loci could be distinguished using their DNA fingerprint profiles. Fingerprints from a clone of M. persicae were stable over nine parthenogenetic generations showing the absence of major genetic rearrangements (`endomeiosis') during apomictic parthenogenesis. The demonstration that sequences homologous to human minisatellite regions are both present and polymorphic in an invertebrate, coupled with the ability to characterize clones from individuals yielding small quantities of DNA show that genetic fingerprinting should be especially valuable for monitoring the diversity and dynamics of clonal animals in the field.