Investigating the Diversity of Wolbachia across the Spiny Ants (Polyrhachis)

Among insects, Wolbachia is an exceedingly common bacterial endosymbiont with a range of consequences of infection. Despite the frequency of Wolbachia infection, very little is known about this bacteria\u27s diversity and role within hosts, especially within ant hosts. In this study, we analyze the occurrence and diversity of Wolbachia across the spiny ants (Polyrhachis), a large and geographically diverse genus. Polyrhachis samples from throughout the host genus\u27 phylogenetic and biogeographical range were first screened for single infections of Wolbachia using the wsp gene and Sanger sequencing. The multilocus sequence typing (MLST) scheme was then used on these singly infected samples to identify the Wolbachia strains. A Wolbachia phylogeny was inferred from the Polyrhachis samples analyzed in this study as well as other Formicidae MLST profiles from the MLST online database. We hypothesized that three key host factors were impacting Wolbachia diversity within the Polyrhachis genus: biogeography, phylogeny, and species level. The results suggest that the phylogeny and biogeography of Polyrhachis hosts have no impact on Wolbachia diversity; however, species level may have some limited influence. Additionally, Wolbachia strains appear to group according to being either Old World or New World strains. Among the taxa able to form complete MLST allelic profiles, all twenty are seemingly new strains

The Diversity of <i>Wolbachia</i> across the Turtle Ants (Formicidae: <i>Cephalotes</i> spp.)

Wolbachia is a widespread and well-known bacterium that can induce a wide range of changes within its host. Ants specifically harbor a great deal of Wolbachia diversity and are useful systems to study endosymbiosis. The turtle ants (Cephalotes) are a widespread group of tropical ants that rely on gut microbes to support their herbivorous diet for their survival, yet little is known of the extent of this diversity. Therefore, studying their endosymbionts and categorizing the diversity of bacteria within Cephalotes hosts could help to delimit species and identify new strains and can help lead to a further understanding of how the microbiome leads to survival and speciation in the wild. In our study, 116 individual samples were initially tested for positive infection with the wsp gene. Of the initial 116 samples, 9 samples were infected with only one strain of Wolbachia, and 7 were able to be used successfully for multilocus sequence typing (MLST). We used the new MLST data to infer a phylogeny with other Formicidae samples from the MLST online database to identify new Wolbachia strains and related genes, of which only one came back as an exact match. The 18 Wolbachia-positive samples ranged across 15 different species and 7 different countries, which we further test for species identity and geographic correlation. This study is the first comprehensive look into the diversity of Wolbachia in the turtle ants, providing insight into how endosymbionts are oriented in widespread species and providing a strong foundation for further research in host-microbe interactions

The developmental psychopathology of motivation in adolescence

Adolescence is a key period for the emergence of psychopathology, with many psychiatric disorders having their modal age-of-onset during this period. Relative to other periods of the lifespan, susceptibility to a number of psychiatric disorders is greatest during adolescence, particularly in females. In addition, disorders which emerge during adolescence appear to be more enduring and serious than those with a later onset. Although these psychiatric conditions may appear different from each other in terms of their associated behavioral signs or symptoms, this review will argue that they involve common alterations in motivational processes or disturbances in reward processing, although the direction of such changes (hypersensitivity vs. hyposensitivity to reward) and the stage of processing affected (reward anticipation vs. receipt) may differ across broader groupings of disorder. Recent behavioral, neuropsychological and neuroimaging research on reward processing in children, adolescents, and adults with these conditions will be described and evaluated. In addition, this article will consider what these studies tell us about their etiology and highlight gaps in our knowledge base. The review will also attempt to explain why adolescence is a period of elevated risk for the development of psychopathology, by discussing normative changes in reward processing in humans and animals