Molecular phylogeny of the Raphidiidae (Raphidioptera)*

We present a molecular phylogeny of the family Raphidiidae including representatives of 21 of the 26 genera. Sequences from the nuclear gene for the large subunit ribosomal RNA (28S rRNA) and the mitochondrial cytochrome c oxidase subunit 3 gene (cox3) were used. For the phylogenetic reconstructions we applied automated and manual approaches for sequence alignment and different evolutionary models and tree building algorithms. The trees based on the two alignment approaches were rather similar in their overall topology. A combination of both marker sequences increased the resolution of the trees. The six clades within the raphidiid family that emerged represent either single genera or groups of genera, namely: (i) the Nearctic genus Agulla Navás, (ii) the Nearctic/Central American genus Alena Navás, (iii) the Central Asiatic and Eastern Palaearctic genus Mongoloraphidia H. Aspöck & U. Aspöck, (iv) the Palaearctic Puncha clade, (v) the western Mediterranean Ohmella clade, and (vi) the Palaearctic Phaeostigma clade. The New World taxa Agulla and Alena are placed as successive out‐groups to a monophyletic Palaearctic clade. The Mongoloraphidia clade is distributed in the eastern Palearctic while the remaining three clades are exclusively (Ohmella clade) or mainly distributed in the western Palaearctic. The early radiation of extant Raphidiidae is interpreted based on the phylogenetic tree obtained in the present study, and the geological and palaeobiological processes around the K–T boundary.     

Control of Protein Synthesis in Acanthamoeba castellanii

During development of Acanthamoeba castellanii in a non-nutrient medium, the pattern of synthesis of proteins changes. Comparison of in vivo and in vitro patterns of protein synthesis reveals concomitant relative increases of five proteins, indicating a control of synthesis of these proteins at the level of the RNA content. The decrease in the overall rate of protein synthesis and relative decreases in the synthesis of actin and ribosomal proteins during development, not accompanied by equivalent changes in the content of mRNA, suggest control mechanisms also at the level of translation. Patterns of ribosomal proteins do not change qualitatively during encystation, indicating that the inhibition in the overall rate of protein synthesis and the formation of inactive monosomes is not controlled by this mechanism; however, phosphorylation of one ribosomal protein, S 3, is observed occasionally during encystation. Phosphorylation of S 3 is also detected after transfer of stationary phase cells into fresh nutrient medium. It was found that only such cells having RNA of aberrant properties are able to phosphorylate S 3 after transfer into fresh nutrient medium. Since these changes in the property of RNA are never observed in cysts, in which phosphorylation of S 3 sometimes occurs, it is concluded that either other alterations in the properties of RNA than those detected or other parameters are responsible for changes in phosphorylation of S 3.