Figures and data
Parasitism facilitates interspecific horizontal transfer of Wolbachia.
(a) Phylogeny of Wolbachia surface protein (wsp) genes retrieved from NCBI. (b) Effect of parasitism, plant-sharing, and predation on the genetic distance of wsp between species. (c) Relationship between species divergence time and the genetic distance of wsp between species. (d) Phylogeny of representative wsp sequences from Trichogramma wasps and lepidopterans. Color red and black represent wsp sequences from Trichogramma wasp and lepidopterans, respectively.
Transfer of Wolbachia from the parasitoid wasp, Encarsia formosa, to its host, Bemisia tabaci.
(a) Phylogenetic analysis of the wsp gene from B. tabaci and its parasitoid wasps. The colors black, red, purple, and gray represent wsp sequences from B. tabaci, En. formosa, other parasitoids of B. tabaci, and other species, respectively. (b) Scheme of the experimental design for studying the transmission of Wolbachia from En. formosa to B. tabac. (c–d) Effects of En. formosa on (c) the infection rate of Wolbachia and (d) the proportion of females in B. tabaci populations. Data are presented as the means ± standard errors (SE) (n = 3).
Parasitism failure mediates Wolbachia transfer from En. formosa to B. tabaci.
(a–c) Effects of 60 Gy radiation on (a) the fecundity of En. formosa over a 12-hour period, (b) the rate of successful parasitism, and (c) the Wolbachia infection rate in surviving whiteflies. Data are presented as the means + SEs (n = 20). ***: p < 0.001. (d–f) Fluorescence in situ hybridization (FISH) visualization of Wolbachia in nonparasitized and parasitized 3rd instar nymphs, as well as parasitized 2nd instar nymphs of B. tabaci. The images present a combination of bright field and fluorescence. E: injected eggs from En. formosa.
Vertical transmission of Wolbachia from En. formosa in B. tabaci.
(a) Scheme of the study design for Wolbachia vertical transmission in B. tabaci. Adult whiteflies that survived from En. formosa parasitism were denoted as G0. After pairing and oviposition, the infection status of Wolbachia in the female parent was examined. Only the offsprings from Wolbachia-infected female whiteflies were maintained. (b) The vertical transmission rate of Wolbachia across five generations in B. tabaci. Data are presented as the means + SEs (n = 9). ns.: no significant differences. (c–e) FISH visualization of Wolbachia in G3 B. tabaci (c) nymph, (d) male adult, and (e) female adult. The images present a combination of bright field and fluorescence. B: bacteriocyte; E: eggs in the ovary of a female whitefly.
Fitness costs in B. tabaci induced by Wolbachia from En. formosa.
(a–e) The effects of En. formosa Wolbachia on B. tabaci (a) female fecundity, (b) egg hatching rate, (c) immature survival rate, (d) female proportion, and (e) developmental time. Data are presented as the means + SEs (n = 60). ***: p < 0.001; ns.: no significant differences.
Fitness in Bemisia tabaci of different cross combinations
Primers used in this study
Subsampling by (a) shuffling species pairs, (b) controlling divergent time or (c) last common ancestor.
For each method, 1000 replicates were randomly generated. Details are provided in the Methods and Materials. Red dots indicate the observed minimum interspecific distances of wsp for different species pair categories.
Alignment of wsp sequences detected from En. formosa and B. tabaci in the cage experiment.
Relative titer of Wolbachia in En. formosa after radiation.
Relative Wolbachia titer in radiated female adults of En. formosa were evaluated using qPCR of the Wolbachia ftsZ gene. The 28S rRNA gene of En. formosa was used as the reference. Data are presented as the means ± SEs (n = 5).
FISH visualization of Wolbachia in parasitized and nonparasitized nymphs of B. tabaci.
(a–c) Fluorescence (a), bright field (b) and combined (c) images of parasitized 2nd instar nymph of B. tabaci. (d–f) Fluorescence (d), bright field (e) and combined (f) images of parasitized 3rd instar nymph of B. tabaci. (g–i) Fluorescence (g), bright field (h) and combined (i) images of nonparasitized 2nd instar nymphs of B. tabaci. The combined photos are identical to the photos shown in Fig. 3d–f. E: injected eggs from En. formosa.
FISH visualization of Wolbachia in G3 B. tabaci.
(a–c) Fluorescence (a), bright field (b) and combined (c) of G3 whitefly nymph. (d–f) Fluorescence (d), bright field (e) and combined (f) images of G3 whitefly female adults. (g–i) Fluorescence (g), bright field (h) and combined (i) images of G3 whitefly male adults. The combined photos are identical to the photos shown in Fig. 4c–e. B: bacteriocyte; E: eggs in ovary of female whitefly.
Maximum likelihood phylogenetic analysis of detected Wolbachia strains in B. tabaci and En. formosa.
(a) Phylogenetic tree constructed using five MLST genes (i.e., coxA, fbpA, gatB, hcpA, ftsZ). (b) Phylogenetic tree constructed using the wsp gene. The bootstrap values are represented at the nodes. Sequences obtained in this study are emphasized in bold.
PCR detection of Wolbachia in B. tabaci.
M: DNA marker; lane 1: Wolbachia-positive whitefly; lane 2: Wolbachia-negative whitefly; lane 3: En. formosa as a positive control; lane 4: ddH2O as a negative control.
Survival of En. formosa after radiation at various doses.
Data are presented as the means ± SEs (n = 8).
Lengths (a) and widths (b) of En. formosa eggs after irradiation at various doses.
Data are presented as the means ± SEs. The sample sizes are typically 10, with the exception of day 3 post-irradiation at 80 Gy and 100 Gy, where the sample sizes are 3 and 2, respectively. This reduction in sample size is due to the scarcity of eggs resulting from irradiation.
