Genetic distinctness of parthenogenetic forms of European Polydrusus weevils of the subgenus Scythodrusus

Abstract

Among eight species of Polydrusus weevils which belong to subgenus Scythodrusus, at least two possess parthenogenetic forms: P. (S.) inustus and P. (S.) pilifer. Both of these species consist of dioecious populations in the Caspian area and of parthenogenetic populations in Eastern Europe (P. (S.) inustus), the Caucasus region (both species) and Middle Asia (P. (S.) pilifer). The origin of parthenogenesis in this subgenus is unresolved; however some data suggest that the parthenogenetic forms are of hybrid ancestry. The genetic distinctness of parthenogenetic Scythodrusus was assessed on the basis of COII, ITS2, EF1‐α and Wolbachiawsp, 16S ribosomal DNA, ftsZ and hcpA sequence comparisons. Both taxa turned out to be monophyletic for all markers, which is an evidence against hybridization of their dioecious ancestors. On the other hand, a high frequency of heterozygous P. (S.) inustus females suggests an origin resulting from hybridization between genetically distinct dioecious representatives of this species. Very similar strains of Wolbachia supergroup A were found in both species, indicating that they have been either inherited from a common ancestor or were transmitted between parthenogenetic Scythodrusus weevils and probably spread randomly across their ranges.

Selective sweep of Wolbachia and parthenogenetic host genomes – the example of the weevil Eusomus ovulum

“…The level of genetic diversity in E. ovulum populations recorded here is similar to that found in another parthenogenetic weevil, P. inustus , which lives in the same habitat in Europe and belongs to the same subfamily (Kajtoch & Lachowska‐Cierlik, ; Kajtoch et al ., ). The mitochondrial genes of both species show star‐like phylogenies with the single most common (and possibly ancestral) haplotype and several derived haplotypes.…”

“…All other parthenogenetic weevils that have been genetically investigated so far (Saura et al ., ; Tomiuk et al ., ; Stenberg et al ., ; Kajtoch & Lachowska‐Cierlik, ; Kajtoch et al ., ) have shown at least some level of genetic diversity across their populations. Moreover, it is known that some parthenogenetic weevils show high heterozygosity in their nuclear genomes, eg in O. scaber (Saura et al ., ; Stenberg et al ., ), P. mollis (Saura et al ., ; Tomiuk et al ., ) and P. inustus (Kajtoch & Lachowska‐Cierlik, ; Kajtoch et al ., ). It was postulated that high heterozygosity in nucDNA is a strong argument for the hybrid origin of parthenogenetic weevils (Saura et al ., 1993).…”

“…Many of these species have also been investigated cytogenetically, which has led to the description of several polyploid lineages with prevalent tri‐ and tetraploids (Lachowska et al ., ; Rożek et al ., ). The best known parthenogenetic forms, including genetics, are found amongst Polydrusus ( P. mollis , Suomalainen, ; Lokki et al ., ; Saura et al ., ; Tomiuk et al ., ; P. inustus and P. pilifer complex, Korotyaev & Meleshko, ; Kajtoch & Lachowska‐Cierlik, ; Kajtoch et al ., ) and Otiorhynchus weevils ( O. scaber , Saura et al ., ; Stenberg et al ., ; and O. salicis , Saura et al ., ). Moreover, Wolbachia infection has been confirmed for parthenogenetic forms of Polydrusus weevils (Kajtoch & Lachowska‐Cierlik, ); however, the role of this bacterium in parthenogenesis induction has not been confirmed (Kajtoch et al ., ).…”

“…The best known parthenogenetic forms, including genetics, are found amongst Polydrusus ( P. mollis , Suomalainen, ; Lokki et al ., ; Saura et al ., ; Tomiuk et al ., ; P. inustus and P. pilifer complex, Korotyaev & Meleshko, ; Kajtoch & Lachowska‐Cierlik, ; Kajtoch et al ., ) and Otiorhynchus weevils ( O. scaber , Saura et al ., ; Stenberg et al ., ; and O. salicis , Saura et al ., ). Moreover, Wolbachia infection has been confirmed for parthenogenetic forms of Polydrusus weevils (Kajtoch & Lachowska‐Cierlik, ); however, the role of this bacterium in parthenogenesis induction has not been confirmed (Kajtoch et al ., ). Finally, Wolbachia has been found and examined in other, extra‐European, weevils, and the role of infection in the induction of parthenogenesis has been postulated for American Naupactini (Werren et al ., ; Rodriguero et al ., ) and Lissorhoptrus oryzophilus (Stenopelmini) (Chen et al ., ), for example.…”

Molecular barcoding for central-eastern European Crioceris leaf-beetles (Coleoptera: Chrysomelidae)

“…Conservation units have been so far identified for the central and eastern European populations of the xerothermic weevil Centricnemus leucogrammus (Germ.) [48], and that pattern is likely to be common to many steppe-xerothermic beetles and other invertebrates.…”