Wolbachia Has Two Different Localization Patterns in Whitefly Bemisia tabaci AsiaII7 Species.

The whitefly Bemisia tabaci is a cosmopolitan insect species complex that harbors the obligate primary symbiont Portiera aleyrodidarum and several facultative secondary symbionts including Wolbachia, which have diverse influences on the host biology. Here, for the first time, we revealed two different localization patterns of Wolbachia present in the immature and adult stages of B. tabaci AsiaII7 cryptic species. In the confined pattern, Wolbachia was restricted to the bacteriocytes, while in the scattered pattern Wolbachia localized in the bacteriocytes, haemolymph and other organs simultaneously. Our results further indicated that, the proportion of B. tabaci AsiaII7 individuals with scattered Wolbachia were significantly lower than that of confined Wolbachia, and the distribution patterns of Wolbachia were not associated with the developmental stage or sex of whitefly host. This study will provide a new insight into the various transmission routes of Wolbachia in different whitefly species

<i>Wolbachia</i> Has Two Different Localization Patterns in Whitefly <i>Bemisia tabaci</i> AsiaII7 Species

<div><p>The whitefly <i>Bemisia tabaci</i> is a cosmopolitan insect species complex that harbors the obligate primary symbiont <i>Portiera aleyrodidarum</i> and several facultative secondary symbionts including <i>Wolbachia</i>, which have diverse influences on the host biology. Here, for the first time, we revealed two different localization patterns of <i>Wolbachia</i> present in the immature and adult stages of <i>B</i>. <i>tabaci</i> AsiaII7 cryptic species. In the confined pattern, <i>Wolbachia</i> was restricted to the bacteriocytes, while in the scattered pattern <i>Wolbachia</i> localized in the bacteriocytes, haemolymph and other organs simultaneously. Our results further indicated that, the proportion of <i>B</i>. <i>tabaci</i> AsiaII7 individuals with scattered <i>Wolbachia</i> were significantly lower than that of confined <i>Wolbachia</i>, and the distribution patterns of <i>Wolbachia</i> were not associated with the developmental stage or sex of whitefly host. This study will provide a new insight into the various transmission routes of <i>Wolbachia</i> in different whitefly species.</p></div

The percentage of <i>Wolbachia</i> location patterns in different stages of AsiaII7 <i>Bemisia tabaci</i>.

<p>For egg, nymph, male and female adults, 56, 46, 47 and 57 individuals (three repeats in total) were successfully visualized by FISH respectively. The differences between the percentages of scattered and confined <i>Wolbachia</i> were compared using t-test, the “***” over the bars mean significantly differences between the percentages at α = 0.01 level. T = -24.30, P = 0.0017 for egg; T = -27.89, P = 0.0013 for nymph; T = -16.09, P = 0.0038 for male and T = -22.02, P = 0.0021 for female adults.</p

FISH visualization of <i>Wolbachia</i> in the female adults of AsiaII7 <i>B</i>. <i>tabaci</i>.

<p>Panel a-b: confined and scattered <i>Wolbachia</i> in female adults; panel c: the negative control whitefly female hybridization without specific probe Left panels: fluorescence in dark field; right panels: fluorescence in bright field. B: bacteriome in whitefly host, H: haemolymph tissue of whitefly host.</p

The infection of <i>Wolbachia</i> in the different stages of AsiaII7 <i>Bemisia tabaci</i>.

<p><i>Wolbachia</i> was detected by PCR with the specific <i>wsp</i> primers, an expected DNA band of approximately 610 bp positively appeared in all the samples. M: DNA marker; Lanes 1–6 are positive control (<i>Portiera</i>, ~1000 bp), negative control (ddH₂O), egg, nymph, male and female adults of AsiaII7 respectively.</p

FISH visualization of <i>Wolbachia</i> in the eggs of AsiaII7 <i>Bemisia tabaci</i>.

<p>Panel a-b: confined and scattered <i>Wolbachia</i> in whitefly eggs; panel c: the negative control whitefly egg hybridization without specific probe. Left panels: fluorescence in dark field; right panels: fluorescence in bright field. E: AsiaII7 <i>B</i>. <i>tabaci</i> egg.</p