Molecular systematics of the butterfly tribe Preponini (Nymphalidae: Charaxinae)

The nymphalid butterfly tribe Preponini includes some of the Neotropical region's most spectacular and familiar butterflies, but the taxonomy of the group nevertheless remains unstable. Several recent studies of Nymphalidae phylogeny have suggested that both the tribe itself and several genera might not be monophyletic, but to date taxon sampling has not been sufficiently comprehensive to allow informed revision of the group's systematics. We therefore conducted the first complete species‐level phylogenetic study of the tribe to establish a firm higher classification. We used DNA sequence data from three genes, the two mitochondrial genes cytochrome oxidase subunits I and II (COI and COII), and the nuclear gene elongation factor‐1α (EF‐1α), to reconstruct the phylogeny of the tribe using maximum likelihood (ML), maximum parsimony (MP) and Bayesian inference (BI). We included 48 individuals representing the 22 recognised Preponini species, and an additional 25 out‐group taxa to explore taxonomic limits at different levels. Firstly, we found that Anaeomorpha splendida Rothschild never grouped with remaining Preponini, so that maintaining monophyly of the tribe requires the taxon to be excluded, and we thus reinstate the tribe Anaeomorphini stat.rev. Secondly, we investigated generic limits, in particular the relationship of Noreppa Rydon to Archaeoprepona Fruhstorfer, and that of Agrias Doubleday to Prepona Boisduval. The molecular results coupled with previous morphological studies suggest that Noreppa syn.n should be synonymised with Archaeoprepona, and that Agrias syn.n should be synonymised with Prepona. We found Prepona pheridamas (Cramer) to be sister to all other Prepona, and markedly divergent from them in both morphology and DNA sequences, suggesting the possibility that it should be placed in a separate genus. We also found a number of cases of significant DNA sequence divergence and paraphyly or polyphyly within putative species that require further taxonomic attention, including Prepona claudina (Godart) stat.n. and Prepona narcissus (Staudinger) stat.n., Prepona pylene Hewitson and Prepona deiphile (Godart). Future research should focus on a broader population sampling of widespread, polymorphic Preponini species to thoroughly revise the current species‐level taxonomy, thus creating a solid foundation for studies in ecology and conservation.     

Sudden expansion of a single brown bear maternal lineage across northern continental Eurasia after the last ice age: a general demographic model for mammals?

The brown bear has proved a useful model for studying Late Quaternary mammalian phylogeography. However, information is lacking from northern continental Eurasia, which constitutes a large part of the species' current distribution. We analysed mitochondrial DNA sequences (totalling 1943 bp) from 205 bears from northeast Europe and Russia in order to characterize the maternal phylogeography of bears in this region. We also estimated the formation times of the sampled brown bear lineages and those of its extinct relative, the cave bear.
Four closely related haplogroups belonging to a single mitochondrial subclade were identified in northern continental Eurasia. Several haplotypes were found throughout the whole study area, while one haplogroup was restricted to Kamchatka. The haplotype network, estimated divergence times and various statistical tests indicated that bears in northern continental Eurasia recently underwent a sudden expansion, preceded by a severe bottleneck. This brown bear population was therefore most likely founded by a small number of bears that were restricted to a single refuge area during the last glacial maximum. This pattern has been described previously for other mammal species and as such may represent one general model for the phylogeography of Eurasian mammals. Bayesian divergence time estimates are presented for different brown and cave bear clades. Moreover, our results demonstrate the extent of substitution rate variation occurring throughout the phylogenetic tree, highlighting the need for appropriate calibration when estimating divergence times.     

cpFBPaseII, a novel redox-independent chloroplastic isoform of fructose-1,6-bisphosphatase

A full-length FBPase cDNA has been isolated from Fragaria  ×  ananassa (strawberry) corresponding to a novel putative chloroplastic FBPase but lacking the regulatory redox domain, a characteristic of the plastidial isoenzyme (cpFBPaseI). Another outstanding feature of this novel isoform, called cpFBPaseII, is the absence of the canonical active site. Enzymatic assays with cpFBPaseII evidenced clear Mg²⁺-dependent FBPase activity and a K _m for fructose-1,6-bisphosphate (FBP) of 1.3 m m . Immunolocalization experiments and chloroplast isolation confirmed that the new isoenzyme is located in the stroma. Nevertheless, unlike cpFBPaseI, which is redox activated, cpFBPaseII did not increase its activity in the presence of either DTT or thioredoxin f (TRX f ) and is resistant to H₂O₂ inactivation. Additionally, the novel isoform was able to complement the growth deficiency of the yeast FBP1 deletion fed with a non-fermentable carbon source. Furthermore, orthologues are restricted to land plants, suggesting that cpFBPaseII is a novel and an intriguing chloroplastic FBPase that emerged late in the evolution of photosynthetic organisms, possibly because of a pressing need of land plants.     

Host plant effects on parasitoid attack on the leaf beetle<Emphasis Type="Italic"> Chrysomela lapponica</Emphasis>

Larvae of the leaf beetle Chrysomela lapponica obtain salicyl glucosides (SGs) from the host plant to produce a defensive secretion with salicylaldehyde. In northern Russia, larvae and pupae experience high parasitism by the phorid fly Megaselia opacicornis and tachinid fly Cleonice nitidiuscula. We compared the suitability of the SG-rich Salix borealis and SG-poor S. caprea and S. phylicifolia to Ch. lapponica and tested whether enemy pressure on Ch. lapponica varies among host species that differ in SG content. In the laboratory, survival of Ch. lapponica larvae was higher on S. borealis than on S. caprea and S. phylicifolia, while adult body mass was higher on S. borealis and S. caprea than on S. phylicifolia. In the field, parasitism by both M. opacicornis and Cl. nitidiuscula was greater on beetles from S. borealis than from the SG-poor S. caprea or S. phylicifolia. In a laboratory choice test, the pupal parasitoid M. opacicornis laid similar numbers of eggs on beetles reared on SG-rich and SG-poor willows, suggesting that the host plant-derived defence is not effective against this parasitoid. In a field enemy-exclusion experiment, beetle survival was greatly enhanced by the exclusion of enemies, but survival rates did not differ between S. borealis and S. caprea, although larvae developed faster on S. borealis. On the other hand, parasitism and predation were observed more often on S. borealis than on S. caprea. Thus, beetle larvae perform better but also suffer higher predation and parasitism on S. borealis than on SG-poor willows. Ch. lapponica does not appear to obtain enemy-free space by feeding on SG-rich willow species.     

Callus Induction and Plant Regeneration in Alstroemeria

Callus was induced from mature embryos of Alstroemeria cv. ‘Butterfly’cultured on MS medium supplemented with 2·0 or 4·0mg dm^–3 2,4–D or picloram and incubated at 25°Cin the dark. The effect of auxin concentration and precultureof embryos was studied. Callus was capable of regeneration aftertransfer to MS medium containing 4.0 mg dm°3 BAP. Shootsand whole plantlets were regenerated. The effect of growth regulators,used in the callus induction medium and the regeneration medium,on plant regeneration was studied Key words: Alstroemeria, callus, plant regeneration.     

Development of taxon‐specific sequence characterized amplified region (SCAR) markers based on actin sequences and DNA amplification fingerprinting (DAF): a case study in the Phoma exigua species complex

Phoma exigua is considered to be an assemblage of at least nine varieties that are mainly distinguished on the basis of host specificity and pathogenicity. However, these varieties are also reported to be weak pathogens and secondary invaders on non‐host tissue. In practice, it is difficult to distinguish P. exigua from its close relatives and to correctly identify isolates up to the variety level, because of their low genetic variation and high morphological similarity. Because of quarantine issues and phytosanitary measures, a robust DNA‐based tool is required for accurate and rapid identification of the separate taxa in this species complex. The present study therefore aims to develop such a tool based on unique nucleotide sequence identifiers. More than 60 strains of P. exigua and related species were compared in terms of partial actin gene sequences, or analysed using DNA amplification fingerprinting (DAF) with short, arbitrary, mini‐hairpin primers. Fragments in the fingerprint unique to a single taxon were identified, purified and sequenced. Alignment of the sequence data and subsequent primer trials led to the identification of taxon‐specific sequence characterized amplified regions (SCARs), and to a set of specific oligonucleotide combinations that can be used to identify these organisms in plant quarantine inspections.