Diversity of <i>mariner</i>-like elements in Orthoptera

Mariner-like elements (MLEs) are among the most widespread DNA transposable elements in eukaryotes. Insects were the first organisms in which MLEs were identified, however the diversity of MLEs in the insect order Orthoptera has not yet been addressed. In the present study, we explore the diversity of MLEs elements in 16 species of Orthoptera belonging to three infraorders, Acridoidea (Caelifera), Grylloidea (Ensifera), and Tettigoniidea (Ensifera) by combining data mined from computational analysis of sequenced degenerative PCR MLE amplicons and available Orthoptera genomic scaffolds. In total, 75 MLE lineages (Ortmar) were identified in all the studied genomes. Automatic phylogeny-based classification suggested that the current known variability of MLEs can be assigned to seven statistically well-supported phylogenetic clusters (I–VII), and the identified Orthoptera lineages were distributed among all of them. The majority of the lineages (36 out of 75) belong to cluster I; 20 belong to cluster VI; and seven, six, four, one and one lineages belong to clusters II, IV, VII, III, and V, respectively. Two of the clusters (II and IV) were composed of a single Orthoptera MLE lineage each (Ortmar37 and Ortmar45, respectively) which were distributed in the vast majority of the studied Orthoptera genomes. Finally, for 16 Orthoptera MLE lineages, horizontal transfer from the distantly related taxa belonging to other insect orders may have occurred. We believe that our study can serve as a basis for future researches on the diversity, distribution, and evolution of MLEs in species of other taxa that are still lacking the sequenced genomes

Parasites of the genus Nosema, Crithidia and Lotmaria in the honeybee and bumblebee populations : a case study in India

The populations of honeybees and bumblebees have been decreasing around the world in the recent decades. A variety of pathogens and parasites, including  bacteria, fungi, protozoa, nematodes, mites and insects play signi ficant role in honeybee and bumblebee colonies loss. Pa rasites of the genus Nosema (Microsporidia: Nosematidae) and the genera Crithidia and Lotmaria (Kinetoplastida: Trypanosomatidae) have a significant negative impact on honeybee and bumblebee colonies. Recent  studies of nuclear DNA markers of these parasites allowed to describe new species and genetic variants. The aim of this study was to investigate the Microsporidia (Nosema spp.) and Trypanosomatidae (Crithidia spp. and Lotmaria  passim) prevalence and genetic diversity in honeybee and bumble bee populations of Indian territories that haven’t been studied before. In total 119 specimens of 4 honeybee and 5 bumblebee species were analyzed in this study. The prevalence of parasites in honeybee and bumblebee po pulations of the two Indian states (Jammu and Kashmir, Karnataka) were identified using PCR with primers specific for the ribosomal RNA genes cluster of Nosema, Crithidia and Lotmaria species. Co­infection by microsporidian and trypanosomatid parasites was detected in several honeybee and bumblebee specimens from Jammu and Kash mir state. Comparative analysis of ribosomal RNA genes sequences showed that honeybee samples from India studied were infected by N. bombi, N. ceranae and L. passim.  Bumblebee populations were infected by Nosema D, Crithidia bombi and Crithidia expoeki. No honeybee’s specimen with trypanosomatid infection was found in Karnataka state. For the first time N. bombi infection was detected in the honeybee population. The studies of distribution of microsporidia and trypanosomatid parasites among the honeybee and bumblebee populations all over the World were summarized and supplemented