Obligately intracellular Wolbachia bacteria infect numerous invertebrates and often manipulate host reproduction to facilitate the spread of infection. An example of reproductive manipulation is Wolbachia-induced cytoplasmic incompatibility (CI), which occurs commonly in insects. This CI has been the focus both of basic scientific studies of naturally occurring invasion events and of applied in...

Gene flow between populations of Culex pipiens L. is relevant to observed differences in disease transmission, insecticide resistance, behavior, and physiology. Intracellular Wolbachia bacteria have been hypothesized to affect gene flow in insects. Specifically, Wolbachia cause a form of embryonic mortality known as cytoplasmic incompatibility (CI) in crosses between individuals with different ...

High-resolution autoradiography has been used to establish that during the incompatibility reaction that follows fusion between plasmodia of a 'killer' and a 'sensitive' strain of the myxomycete Physarum polycephalum, the nuclei of the sensitive strain are selectively damaged, enclosed in vacuoles and eliminated from the cytoplasm. This damage is visible as increased chromatin condensation and ...

In a multidatabase system schematic con icts between two objects are usually of inter est only when the objects have some semantic a nity In this paper we try to reconcile the two perspectives We rst de ne the concept of semantic proximity and provide a semantic taxonomy We then enumerate and classify the schematic and data con icts We discuss possible semantic similarities between two objects ...

Reinforcement refers to the evolution of increased mating discrimination against heterospecific individuals in zones of geographic overlap and can be considered a final stage in the speciation process. One the factors that may affect reinforcement is the degree to which hybrid matings result in the permanent loss of genes from a species' gene pool. Matings between females of Drosophila subquina...

Tagosodes orizicolus (Homoptera: Delphacidae) is one of the main constraints of the rice production in the Neotropics. This planthopper produces severe damages as a phloem feeder, causes mechanical injury during oviposition and vectors the rice hoja blanca virus (RHBV). The main objective of this study was to determine the genetic diversity of T. orizicolus populations from three rice growing r...

The relationship between cytoplasmic incompatibility and the obligate intracellular alphaproteobacteria Wolbachia has for a long time been reported. Although molecular mechanisms responsible this reproductive alteration are beginning to be understood, effects of on germ cell structure dynamics have not yet fully investigated. We report here that presence in infected cysts elongating spermatids ...

Cytoplasmic bacteria of the genus Wolbachia are best known as the cause of cytoplasmic incompatibility (CI): many uninfected eggs fertilized by Wolbachia-modified sperm from infected males die as embryos. In contrast, eggs of infected females rescue modified sperm and develop normally. Although Wolbachia cause CI in at least five insect orders, the mechanism of CI remains poorly understood. Her...

Introduction ....................................................................................................................................283 DeÞning a Species and Symbiont..................................................................................................284 Wolbachia as a Model System for Symbiont-Induced Speciation................................................285 Abund...