Association between Wolbachia and Spiroplasma within Drosophila neotestacea: an emerging symbiotic mutualism?

Abstract

Interspecific mutualism can evolve when specific lineages of different species tend to be associated with each other from one generation to the next. Different maternally transmitted endosymbionts occurring within the same cytoplasmic lineage fulfil this requirement. Drosophila neotestacea is infected with maternally transmitted Wolbachia and Spiroplasma, which are cotransmitted at high frequency in natural populations. Molecular phylogenetic evidence indicates that both endosymbionts have been present in D. neotestacea for considerable evolutionary periods. Thus, conditions are suitable for the evolution of mutualism between them. In support of this possibility, there is a significant positive association between Wolbachia and Spiroplasma infection in many samples of D. neotestacea from natural populations. Theoretically, such a positive association can result from either mutualism between these endosymbionts or recent spread. Collections from present-day populations suggest that recent spread and mutualism have both operated to generate the positive association between Wolbachia and Spiroplasma. If selection acts on the combination of these two endosymbionts, they may be in the early stages of evolution of a more complex, cooperative association.

Male killing Spiroplasma protects Drosophila melanogaster against two parasitoid wasps

“…These observations provide empirical evidence for a mechanism by which two cytoplasmically transmitted endosymbionts may evolve cooperation. If the observed additive benefits of coinfection by Spiroplasma and Wolbachia against Lh are ecologically relevant, we expect a nonrandom positive association of the two symbionts in natural populations of D. melanogaster, such as that observed in D. neotestacea (Jaenike et al, 2010a). Nonetheless, Ventura et al (2012) failed to detect a significant association between the two symbionts in natural populations of D. melanogaster in Brazil.…”

“…On the basis of the nonrandom positive association of Wolbachia and Spiroplasma observed in D. neotestacea populations, Jaenike et al (2010a) suggest that mutualism between the two symbionts might have evolved, but evidence for a cooperation mechanism itself has not been found. In contrast to D. neotestacea, no evidence for significant associations between the two symbionts has been observed in natural populations of D. melanogaster (Ventura et al, 2012).…”

“…In Drosophila, the two defensive Spiroplasma strains known do not appear to engage in reproductive manipulation (Ota et al, 1979;Jaenike et al, 2010a), but several of their close relatives are male killers. One of these male-killing strains is the Melanogaster Sex Ratio Organism (hereafter MSRO), which can co-occur with Wolbachia in certain populations of D. melanogaster.…”

Distribution Patterns of Wolbachia Endosymbionts in the Closely Related Flower Bugs of the Genus Orius: Implications for Coevolution and Horizontal Transfer

“…More specifically, the same or closely related Wolbachia strains have been found in different host species that share the same ecological niche or have host-parasite or predator-prey interactions [23,34]. On the other hand, the Wolbachia phylogeny based on the MLST genes was concordant with the host species phylogeny in some cases, suggesting that vertical inheritance of Wolbachia from a common ancestor has also occurred [15,20]. However, it remains unclear how commonly such coevolutionary processes operate between Wolbachia and its hosts.…”

Effect of Wolbachia Infection on Aging and Longevity-Associated Genes in Drosophila

“…A summary of the impacts of Wolbachia infection on biology of some species of Drosophila genus is present in Table 4.1. In several Drosophila species including D. neotestacea (Jaenike et al 2010), D. mauritania (Giordano et al 1995), D. santomea, D. teissieri, D. yakuba (Zabalou et al 2004;Hughes and Rasgon 2014), Wolbachia causes no reproductive distortions such as CI. In D. simulans, naturally infecting strains wCof, wAu (Hoffmann et al 1996), and wMa (Charlat et al 2003) do not exhibit CI as well.…”