Tracking paternal genes with DALP markers in a pseudoarrhenotokous reproductive system: biparental transmission but haplodiploid-like inheritance in the mite Neoseiulus californicus

The complexity of some sexual reproductive systems in arthropods still leav es both their genetic and epigenetic determinism and their evolutionary sig nificance poorly understood. Pseudoarrhenotoky is characterized by obligate fertilization and differential inactivation and/or elimination of paternal chromosomes in embryos that develop into males. Here, we investigate how t he paternal genome is transmitted in a pseudoarrhenotokous mite, Neoseiulus californicus, using codominant genetic markers detected by DALP (direct am plification of length polymorphism). Transmission patterns of parental alle les through one and two generations are reported at four or five loci corre sponding to four linkage groups. Our data provide strong evidence for selec tive elimination of the paternal genome among male tissues. Sperm contained maternal genes exclusively, whereas some male somatic tissues retained mos t if not all paternal chromosomes. No recombination between parental genome s prior to paternal genome elimination from the embryonic germ line was obs erved. These data allow a reinterpretation of previous phenotypic and cytog enetic observations in these mites, from which we suggest some relevant mec hanistic and evolutionary implications. In addition, this is the first publ ished study using polymorphic codominant loci detected by the recently deve loped DALP method.