Phylogeny of the hyper‐diverse rove beetle subtribe Philonthina with implications for classification of the tribe Staphylinini (Coleoptera: Staphylinidae)

With 71 genera and over 2700 described species, Philonthina is the most speciose subtribe of rove beetle tribe Staphylinini and forms a major component of the largest remaining higher systematics challenge in Staphylinini, the ‘Staphylinini propria’ clade. A related systematics issue concerns the position of the genus Holisus (Hyptiomina), which was recovered within the Neotropical philonthine lineage in several recent analyses of morphology. With the aims of resolving the phylogeny of Philonthina and the position and, thus, validity of Hyptiomina, we performed phylogenetic analyses of the tribe Staphylinini based on molecular (six genes, 4471 bp) and morphological (113 characters) data including 138 taxa from all relevant lineages of Staphylinini. We found that ‘Staphylinini propria’ is a monophylum consisting of six lineages: current subtribes Anisolinina, Philonthina, Staphylinina and Xanthopygina; and two new subtribes, Algonina Schillhammer and Brunke and Philothalpina Chatzimanolis and Brunke. While the previously hypothesized Neotropical lineage of Philonthina was corroborated, Holisus was recovered as a separate subtribe, outside of Philonthina, within an informal ‘Southern Hemisphere clade’. Based on our analyses, we propose tentative new concepts of the polyphyletic genera Belonuchus and Philonthus. We propose the following taxonomic changes: synonymy of the subtribes Staphylinina Latreille (valid name) and Eucibdelina Sharp; resurrection of genera Barypalpus Cameron and Trapeziderus Motschulsky from synonymy with Rientis Sharp and Belonuchus Nordmann, respectively; transfer of 38 Belonuchus species, 16 Hesperus Fauvel species and one Philonthus Stephens species to Trapeziderus as new combinations; transfer of two Hesperus species to Eccoptolonthus Bernhauer as new combinations; transfer of one Belonuchus species to Paederomimus Sharp as a new combination; and transfer of Pridonius Blackwelder new status from its position as a subgenus of Quedius (subtribe Quediina) to Philonthina as a genus, and new combinations for its two described species.     

Coordinate regulation of the four tubulin genes of Chlamydomonas reinhardi.

During cell division and during the induction of tubulin synthesis that accompanies flagellar regeneration in Chlamydomonas reinhardi, four tubulin mRNAs of discrete molecular sizes are produced. During induction two beta tubulin mRNAs (2.47 kb and 2.34 kb) and two alpha tubulin mRNAs (2.26 kb and 2.13 kb) are synthesized in high abundance and in a closely coordinated fashion. Combined data from restriction enzyme mapping (i.e., Southern analysis) of genomic DNA and of Charon 30 recombinant clones bearing inserts of Chlamydomonas tubulin genes provide direct evidence for four distinct tubulin genes in this organism. Dot-blot analysis of the level of hybridization of a 32p nick-translated beta tubulin cDNA to genomic DNA from gametic cells and to a clone containing the beta 1 tubulin gene indicate that each beta 1 tubulin gene is present in one copy per cell. Additional hybridization experiments employing fragments of cDNA clones which selectively anneal to either the 3' or 5' portions of the two alpha tubulin genes or to one or both of the two beta tubulin genes suggest that each tubulin gene is actively transcribed to give rise to one of the four tubulin mRNAs. These observations further suggest that at most four basic types of tubulin subunits are produced by Chlamydomonas and that the heterogeneity of tubulin subunits reported to exist in the flagellar axoneme must arise as a result of post-translational modification.     

The facultative intracellular pathogen Candida glabrata subverts macrophage cytokine production and phagolysosome maturation

Although Candida glabrata is an important human pathogenic yeast, its pathogenicity mechanisms are largely unknown. Immune evasion strategies seem to play key roles during infection, since very little inflammation is observed in mouse models. Furthermore, C. glabrata multiplies intracellularly after engulfment by macrophages. In this study, we sought to identify the strategies that enable C. glabrata to survive phagosome biogenesis and antimicrobial activities within human monocyte-derived macrophages. We show that, despite significant intracellular proliferation, macrophage damage or apoptosis was not apparent, and production of reactive oxygen species was inhibited. Additionally, with the exception of GM-CSF, levels of pro- and anti-inflammatory cytokines were only marginally increased. We demonstrate that adhesion to and internalization by macrophages occur within minutes, and recruitment of endosomal early endosomal Ag 1 and lysosomal-associated membrane protein 1 indicates phagosome maturation. However, phagosomes containing viable C. glabrata, but not heat-killed yeasts, failed to recruit cathepsin D and were only weakly acidified. This inhibition of acidification did not require fungal viability, but it had a heat-sensitive surface attribute. Therefore, C. glabrata modifies the phagosome into a nonacidified environment and multiplies until the host cells finally lyse and release the fungi. Our results suggest persistence of C. glabrata within macrophages as a possible immune evasion strategy.     

Effect of a tail piece cysteine deletion on biochemical and functional properties of an epidermal growth factor receptor-directed IgA2 m(1) antibody

Antibodies of human IgA isotype are critical components of the mucosal immune system, but little is known about their immunotherapeutic potential. Compared with IgG antibodies, IgA molecules carry a C-terminal tail piece extension of 18 amino acids with a free cysteine at position 471. This cysteine is required for the formation of dimeric IgA antibodies, but may impair molecular characteristics of monomeric IgA antibodies as therapeutic reagents. Thus, we generated and characterized a d471-mutated antibody against the epidermal growth factor receptor (EGFR) and compared it to its respective IgA2 m(1) wild type antibody. Both wild type and mutated IgA antibodies demonstrated similar EGFR binding and were similarly efficient in inhibiting EGF binding and in blocking EGF-mediated cell proliferation. Recruitment of Fc-mediated effector functions like antibody-dependent cell-mediated cytotoxicity by monocytes, macrophages or PMN was similar, but the d471-mutated IgA exhibited different biochemical properties compared with wild type antibody. As expected, mutated IgA did not form stable dimers in the presence of human joining (J)-chain, but we also observed reduced levels of dimeric aggregates in the absence of J-chain. Furthermore, glycoprofiling revealed different glycosylation patterns for both antibodies, including considerably less mannosylation of d471-mutated antibodies. Overall, our results demonstrate that the deletion of the C-terminal cysteine of IgA2 did not affect the investigated effector functions compared with wild type antibody, but it improved biochemical properties of an IgA2 m(1) antibody against EGFR, and may thereby assist in exploring the immunotherapeutic potential of recombinant IgA antibodies.     

Fine-Scale Chromosomal Changes in Fungal Fitness

Fungi are frequently exposed to changing environments and must adapt continuously to retain their fitness. This is especially true when changes occur rapidly and toward harsher conditions – a situation, for example, encountered by pathogenic fungi when they infect a host and during the different stages of infections. Here we provide an overview of the role of small-scale genetic exchanges for the fitness of human pathogenic fungi. These alterations can influence host-fungus interactions, and hence the outcome of an infection. We present recent experiments and observations dealing with the importance of the genetic diversity and previous selection pressures of the infecting pool. In addition, we discuss the role of specific niches and disease progression as well as antifungal treatment on fungal microevolution in vivo. We conclude that different mechanisms of small-scale genetic changes allow pathogenic fungi to increase their fitness in the host, and can thus alter the course of infections.     

Early evolution of the hyperdiverse rove beetle tribe Staphylinini (Coleoptera: Staphylinidae: Staphylininae) and a revision of its higher classification

The rove beetle tribe Staphylinini (Staphylinidae: Staphylininae) is a monophyletic lineage of over 5500 relatively large and charismatic species, yet its higher classification remains deeply rooted in historical concepts. Despite recent progress toward inferring phylogenetic relationships within this group using morphological and molecular datasets, relationships among taxa that were united under a polyphyletic “Quediina” remain largely unknown. To infer these relationships, we analysed a six‐gene dataset (4370 bp) using parsimony and model‐based analyses and the results were placed in the context of morphology. While all genes contributed synapomorphies for major lineages or relationships between them, carbamoyl synthetase (CAD), topoisomerase I (TP) and wingless (Wg) were the most informative. TP was generally most informative at the level of subtribe, Wg above this level and CAD throughout the tree. The monophyly of Staphylinini was strongly supported and analyses support seven clades that correspond to higher taxonomic levels, four of which are formally described as subtribes here: Acylophorina stat. rev., Cyrtoquediina new subtribe, Erichsoniina new subtribe and Indoquediina new subtribe. The majority of Staphylinini taxa were recovered within a well‐supported “northern hemisphere clade” that is weakly represented in the southern hemisphere. The composition and morphological diagnosis of the “Staphylinini propria” clade are revised, and the pronotum shape historically associated with this group is shown to have evolved multiple times elsewhere in Staphylinini. The genus Stevensia is moved from Staphylinina to Acylophorina based on morphological evidence. Cyrtoquedius stat. nov., previously a subgenus of Quedius, is raised to the genus level. The following 32 new combinations (from Quedius) are proposed: Cyrtoquedius anthracinus (Solsky); C. arrogans (Sharp); C. basiventris (Sharp); C. bolivianus (Sharp); C. bruchi (Bernhauer); C. clypealis (Sharp); C. concolor (Sharp); C. flavicaudus (Sharp); C. flavinasis (Bernhauer); C. frenatus (Erichson); C. graciliventris (Sharp); C. jacobi (Scheerpeltz); C. jocosus (Sharp); C. labiatus (Erichson); C. laeviventris (Bernhauer); C. mexicanus (Sharp); C. ochropygus (Bernhauer); C. ogloblini (Bernhauer); C. ornatocollis (Bierig); C. protensus (Sharp); C. rufinasus (Sharp); C. verecundus (Sharp); C. verres (Smetana); Indoquedius borneensis (Cameron); I. dispersepunctatus (Scheerpeltz); I. javanus (Cameron); I. malaisei (Scheerpeltz); I. micantiventris (Scheerpeltz); I. parallelicollis (Scheerpeltz); I. philippinus (Cameron); I. recticollis (Scheerpeltz); and I. sanguinipennis (Scheerpeltz). Cyrtoquedius verres is recorded from the state of Georgia (USA) for the first time, which, together with its transfer from Quedius, extends the distribution of the Cyrtoquediina significantly northward into the Nearctic.