Raw data of M. desjardinsi samples collected in Matsudo

Raw data of M. desjardinsi samples collected in Matsud

Mitochondrial haplotypes and Spiroplasma infection status of females collected in 2011 and 2016 from Rapid comeback of males: evolution of male-killer suppression in a green lacewing population

Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing <i>Mallada desjardinsi</i>. An <i>M. desjardinsi</i> population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing <i>Spiroplasma</i> endosymbiont, had a sex ratio near parity in 2016, despite a consistent <i>Spiroplasma</i> prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing <i>Spiroplasma</i> variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly <i>Hypolimnas bolina</i> in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated

Sex ratios of offspring produced by Spiroplasma-infected 2016 females crossed with 2011 males (outbred) or 2016 males (inbred) from Rapid comeback of males: evolution of male-killer suppression in a green lacewing population

Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing <i>Mallada desjardinsi</i>. An <i>M. desjardinsi</i> population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing <i>Spiroplasma</i> endosymbiont, had a sex ratio near parity in 2016, despite a consistent <i>Spiroplasma</i> prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing <i>Spiroplasma</i> variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly <i>Hypolimnas bolina</i> in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated

Infection status of females collected in 2011 and 2016, and sex ratios of their offspring from Rapid comeback of males: evolution of male-killer suppression in a green lacewing population

Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing <i>Mallada desjardinsi</i>. An <i>M. desjardinsi</i> population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing <i>Spiroplasma</i> endosymbiont, had a sex ratio near parity in 2016, despite a consistent <i>Spiroplasma</i> prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing <i>Spiroplasma</i> variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly <i>Hypolimnas bolina</i> in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated

Sample sheet for Eurema mandarina

Sample sheet of Eurema mandarina adults collected in Tanegashima Island, Japan, in 2015. It contains sample codes, date of sampling, sex, latitudes and longitudes of collected sites, Wolbachia infection status (C: singly infected with wCI, CF: doubly infected with wCI and wFem, NA: not analysed), numbers of female offspring and male offspring where available, and accession numbers of Tpi, COI and COIII

Survivorship of offspring produced by wild-caught females.

<p>Proportion of surviving individuals at the first-instar larval stage (II), the pupal stage (III), the pharate-adult (i.e., moving pupal) stage (IV), and the adult stage (V) among embryos (I). A solid line (red) represents a brood that developed to only females. A broken line (blue) represents a brood that developed to males and females with a ratio not significantly deviated from 1:1 (<i>P</i> > 0.05). A photograph of an adult female is given in the inset.</p

Material and methods from <i>Wolbachia</i>-induced meiotic drive and feminization is associated with an independent occurrence of selective mitochondrial sweep in a butterfly

Maternally inherited <i>Wolbachia</i> endosymbionts manipulate arthropod reproduction in various ways. In the butterfly <i>Eurema mandarina</i>, a cytoplasmic incompatibility inducing <i>Wolbachia</i> strain <i>w</i>CI and the associated mtDNA haplotypes are known to originate from the sister species <i>Eurema hecabe</i>, which offered a good case study for microbe-mediated hybrid introgression. Besides <i>w</i>CI, some females with the Z0 karyotype harbour a distinct <i>Wolbachia</i> strain <i>w</i>Fem, which causes all-female production by meiotic drive and feminization. We report that a considerable proportion of <i>E. mandarina</i> females (65.7%) were infected with both <i>w</i>CI and <i>w</i>Fem (CF) on Tanegashima Island. While females singly infected with <i>w</i>CI (C) produced offspring at a 1 : 1 sex ratio, CF females produced only females. Although Z-linked sequence polymorphism showed no signs of divergence between C and CF females, mtDNA split into two discrete clades; one consisted of C females and the other CF females, both of which formed a clade with <i>E. hecabe</i> but not with uninfected <i>E. mandarina</i>. This suggests that CF matrilines also, but independently, experienced a selective sweep after hybrid introgression from <i>E. hecabe</i>. Distinct evolutionary forces were suggested to have caused C and CF matrilines to diverge, which would be irreversible because of the particular phenotype of <i>w</i>Fem

Infection status of wild-caught <i>M</i>. <i>desjardinsi</i> females and the sex ratio of their offspring.

<p>Infection status of wild-caught <i>M</i>. <i>desjardinsi</i> females and the sex ratio of their offspring.</p

Phylogeny of E. mandarina and E. hecabe based on mitochondrial sequences from <i>Wolbachia</i>-induced meiotic drive and feminization is associated with an independent occurrence of selective mitochondrial sweep in a butterfly

An ML tree of E. mandarina (filled) and E. hecabe (open) based on concatenated sequences of COI and COIII (d). Red circles: CF females. Blue squares: C females. Green triangles: uninfected females. Haplotypes found in Tanegashima samples are shaded with grey. Miyata M, Konagaya T, Yukuhiro K, Nomura M and Kageyama D “Wolbachia-induced meiotic drive and feminization is associated with an independent occurrence of selective mitochondrial sweep in a butterfly.” Biology Letter

Transmission electron micrographs of <i>Spiroplasma</i> and <i>Rickettsia</i> in the female reproductive tissues of <i>M</i>. <i>desjardinsi</i>.

<p><b>a</b>: Ovaries of a female <i>M</i>. <i>desjardinsi</i>. A circle represents a portion subjected to electron microscopy. <b>b</b>: Undifferentiated part of an ovariole, with <i>Rickettsia</i>-like structure in the follicle cells and <i>Spiroplasma</i>-like structure in the oocyte. <b>c</b>,<b>d, e</b>: Magnified images of (b), showing <i>Spiroplasma</i>-like structure. <b>f</b>: Differentiating part of an ovariole, with <i>Rickettsia</i>-like structure in the oocyte and <i>Spiroplasma</i>-like structure in the sheath. S: <i>Spiroplasma</i>; R: <i>Rickettsia</i>; oc: oocyte; fc: follicle cell; sh: sheath; n: nucleus.</p