Morphology-based phylogenetic reconstruction of Cholevinae (Coleoptera: Leiodidae): a new view on higher-level relationships.

The current state of knowledge of the suprageneric relationships in Cholevinae is either derived from informal evaluations of putative synapomorphies or based on molecular studies with limited taxonomic sampling. Here we assessed the higher-level relationships in this subfamily based on a phylogenetic analysis of 97 morphological characters scored for 93 terminals, representing all tribes. Both parsimony and Bayesian analyses were used. The monophyletic origin of Cholevinae was corroborated, except for the unexpected inclusion of Leptinus in the implied weighting analysis. Eucatopini + Oritocatopini were retrieved as basal branches in the evolution of Cholevinae. The monophyletic origin of all remaining Cholevinae was confirmed, which is consistent with molecular evidence. Anemadini was non-monophyletic, in accordance with earlier hypotheses. Cholevini was rendered non-monophyletic by the uncertain inclusion of Prionochaeta and the consistent exclusion of Cholevinus. A close affinity of Ptomaphagini to Sciaphyini and Leptodirini was suggested, although the position of Sciaphyes remains uncertain. The phylogenetic hypothesis of Cholevinae provided here is the most comprehensive presently available. The list of characters shows that a substantial part of the data was obtained from the ventral side. This is a strong argument for a detailed pictorial documentation of the ventral body parts in taxonomic descriptions, in contrast to the common practice of only illustrating the dorsal habitus of the beetles.

Genetic diversity of maize germplasm assessed by retrotransposon-based markers.

Maize is one of the most important crops and also a model for grass genome research. Transposable elements comprise over 78% of the maize genome and their ability to generate new copies makes them good potential markers. Interretrotransposon-amplified polymorphism (IRAP) and retrotransposon microsatellite amplified polymorphism (REMAP) protocols were used for the first time in maize to study the genetic variability between maize cultivars. Ten PCR primers were selected based on a systematic analysis of the sequence conservation in the extremities of different high copy number transposable elements, whereas one primer was chosen based on a microsatellite sequence. Of the 16 primer combinations tested, 14 produced polymorphic bands. These markers were used to identify genetic similarity among 20 maize cultivars selected by their different kernel oil content. Genetic similarity analysis was performed based on the polymorphic band profiles and dendrograms were developed by the unweighted pair-group method with arithmetic averages. Clustering technique revealed that samples were grouped into three clusters that differed in their kernel oil content and size, and in their relative embryo size. In the current investigation, there is evidence that IRAP/REMAP may be useful as markers in maize.

Ancient associations of aquatic beetles and tank bromeliads in the Neotropical forest canopy

Water reservoirs formed by the leaf axils of bromeliads are a highly derived system for nutrient and water capture that also house a diverse fauna of invertebrate specialists. Here we investigate the origin and specificity of bromeliad-associated insects using Copelatinae diving beetles (Dytiscidae). This group is widely distributed in small water bodies throughout tropical forests, but a subset of species encountered in bromeliad tanks is strictly specialized to this habitat. An extensive molecular phylogenetic analysis of Neotropical Copelatinae places these bromeliadicolous species in at least three clades nested within other Copelatus. One lineage is morphologically distinct, and its origin was estimated to reach back to 12-23 million years ago, comparable to the age of the tank habitat itself. Species of this clade in the Atlantic rainforest of southern Brazil and mountain ranges of northern Venezuela and Trinidad show marked phylogeographical structure with up to 8% mtDNA divergence, possibly indicating allopatric speciation. The other two invasions of bromeliad water tanks are more recent, and haplotype distributions within species are best explained by recent expansion into newly formed habitat. Hence, bromeliad tanks create a second stratum of aquatic freshwater habitat independent of that on the ground but affected by parallel processes of species and population diversification at various temporal scales, possibly reflecting the paleoclimatic history of neotropical forests.