Mobile elements create strain-level variation in the services conferred by an aphid symbiont.

Heritable, facultative symbionts are common in arthropods, often functioning in host defence. Despite moderately reduced genomes, facultative symbionts retain evolutionary potential through mobile genetic elements (MGEs). MGEs form the primary basis of strain-level variation in genome content and architecture, and often correlate with variability in symbiont-mediated phenotypes. In pea aphids (Acyrthosiphon pisum), strain-level variation in the type of toxin-encoding bacteriophages (APSEs) carried by the bacterium Hamiltonella defensa correlates with strength of defence against parasitoids. However, co-inheritance creates difficulties for partitioning their relative contributions to aphid defence. Here we identified isolates of H. defensa that were nearly identical except for APSE type. When holding H. defensa genotype constant, protection levels corresponded to APSE virulence module type. Results further indicated that APSEs move repeatedly within some H. defensa clades providing a mechanism for rapid evolution in anti-parasitoid defences. Strain variation in H. defensa also correlates with the presence of a second symbiont Fukatsuia symbiotica. Predictions that nutritional interactions structured this coinfection were not supported by comparative genomics, but bacteriocin-containing plasmids unique to co-infecting strains may contribute to their common pairing. In conclusion, strain diversity, and joint capacities for horizontal transfer of MGEs and symbionts, are emergent players in the rapid evolution of arthropods.

Gut bacteria of adult and larval Cotinis nitida Linnaeus (Coleoptera: Scarabaeidae) demonstrate community differences according to respective life stage and gut region.

The close association between bacteria and insect hosts has played an indispensable role in insect diversity and ecology. Thus, continued characterization of such insect-associated-microbial communities is imperative, especially those of saprophagous scarab beetles. The bacterial community of the digestive tract of adults and larvae of the cetoniine scarab species Cotinis nitida is characterized according to life stage, gut structure, and sex via high-throughput 16S rRNA gene amplicon sequencing. Through permutational ANOVAs of the resulting sequences, bacterial communities of the digestive system are shown to differ significantly between adults and larvae in taxon richness, evenness and relatedness. Significant bacterial community-level differences are also observed between the midgut and hindgut in adult beetles, while no significant host-sex differences are observed. The partitioning between bacterial communities in the larval digestive system is shown through significant differences in two distinct hindgut regions, the ileum and the expanded paunch, but not between the midgut and ileum portion of the hindgut region. These data further corroborate the hypothesis of strong community partitioning in the gut of members of the Scarabaeoidea, suggest hypotheses of physiological-digestive association, and also demonstrate the presence of a seemingly unusual non-scarab-associated taxon. These findings contribute to a general portrait of scarabaeoid digestive tract bacterial communities while illuminating the microbiome of a common new world cetoniine of the Gymnetini-a tribe largely neglected in scarab and beetle microbiome and symbiosis literature.

A systematic literature review and meta-analysis of radioimmunotherapy consolidation for patients with untreated follicular lymphoma.

BACKGROUND: Follicular lymphoma (FL) is characterized by multiple relapses and progressively shorter response durations with subsequent therapies. Despite the development of numerous treatment strategies to reduce the risk of progression, optimal therapeutic strategies for patients with FL remain undefined. Radioimmunotherapy (RIT) with an anti-CD20 antibody linked to iodine-131 or to yttrium-90 has emerged as well-tolerated treatment after induction. We conducted a systematic literature review and meta-analyses to quantify the benefits of consolidative RIT. METHODS: We searched the CENTRAL and MEDLINE libraries, and conference abstracts for reports on phase II/III clinical trials that assessed RIT consolidation for patients with untreated FL. Extracted data included pretreatment disease status, patient characteristics, treatment regimen, response rates, progression-free survival (PFS), and overall survival (OS). Pooled estimates of complete response (CR), overall response (OR), 2- and 5-year PFS and OS rates were computed by using random effects models. RESULTS: Eight studies (n = 783) were included in the meta-analyses. CR rates after RIT ranged from 69.0% to 96.5%, 2-year PFS ranged from 64.8% to 86.1%, and 5-year PFS ranged from 47.0% to 67.3%. The pooled estimates of the CR rate and OR rate were 82.7% (95% CI, 67.4%-91.7%) and 96.2% (95% CI, 90.4%-98.6%), respectively. The pooled estimates for 5-year PFS and OS were 57.6% (95% CI, 47.8%-66.9%) and 90.1% (95% CI, 83.9%-94.1%), respectively. CONCLUSIONS: We believe that these aggregated data can further the discussion on RIT as a consolidation therapy and inform decisions on future study designs Additional studies are needed to compare the benefits of RIT consolidation to maintenance therapy with rituximab.