Phylogenetic analysis of non-stereotyped behavioural sequences with a successive event-pairing method

A new method is proposed which uses transitions among acts in non-stereotyped behavioural sequences as phylogenetic characters. This method is derived from the event-pairing method designed for the phylogenetic study of developmental sequences and from ethological analyses of transition matrices. It is applied to study the phylogenetic relationships within a well-known group, the presocial Zetoborinae cockroaches. The analysis is carried out with three data sets: a behavioural data set with transitions among acts in behavioural dyadic sequences, together with morphological and molecular data sets. Non-stereotyped behaviour proved to be phylogenetically informative and to display low homoplasy. This new method opens an avenue for studying the evolution of behaviour in the framework of phylogenetic analysis, which was restricted until now to the study of stereotyped sequences and/or isolated features involved in courting or building activities.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 853–867.     

Heterochrony in Tingidae (Insecta: Heteroptera): paedomorphosis and/or peramorphosis?

Tingidae (Heteroptera: Insecta) exhibit cephalic tubercles that present a very diverse shape in larvae but that are much simpler in adults. A phylogeny based on adult and last instar characters showed that these tubercles evolved independently from simple to complex states in two clades, and reversed from complex to simple in some taxa. These homoplasies are analysed in the light of ontogenetic sequences and interpreted as heterochronic events. The general trend of evolution of the cephalic tubercles in Tingidae is in mosaic, and could be generally peramorphic, with some isolated cases of paedomorphosis.  Journal compilation © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 71–80. No claim to original French government works.     

Curvilinear Three-Dimensional Modeling of Spinal Curves with Dual Kriging

In spinal deformation studies, three-dimensional reconstruction of the spine is frequently represented as a curve in space fitted to the vertebral centroids. Conventional interpolation techniques such as splines, Bezier and the least squares method are limited since they cannot describe precisely the great variety of spinal morphologies. This article presents a more general technique called dual kriging, which includes two mathematical constituents (drift and covariance) to adjust the interpolated functions to spinal deformity better. The cross-validation technique was used to compare the parametric representations of spinal curves with different combinations of drift and covariance functions. Model validation was performed from a series of analytic curves reflecting typical scoliotic spines. Calculation of geometric torsion, a sensitive parameter, was done to evaluate the accuracy of the kriging models. The best model showed an absolute mean difference of 1.2 x 10(-5) (+/- 7.1 x 10(-5) ) mm(-1) between the analytical and estimated geometric torsions compared to 5.25 x 10(-3) (+/- 3.7 x 10(-2) ) mm(-1) for the commonly used least-squares Fourier series method, a significant improvement in spinal torsion evaluation.     

Characterization of microsatellite markers in the rosewood (Dalbergia monticola Bosser & R. Rabev.)

Dalbergia monticola is one of the major components of the oriental forest of Madagascar. This economically and ecologically important tree is threatened because of the dramatic decrease of the Madagascar forest. We have estimated the genetic diversity and structure of the species by studying nuclear microsatellites. We have developed eight pairs of primers to analyse 215 individuals distributed from the north to the south of the island. These markers will be useful for genetic and ecological studies of this species.     

Genomic reticulation indicates mixed ancestry in Southern-Hemisphere Mytilus spp. mussels

Previous surveys of allozyme variation in smooth-shell Mytilus spp. mussels have reported the presence in the Southern Hemisphere of both Mytilus edulis and Mytilus galloprovincialis mussels. In the present study, nuclear DNA markers mac-1 and Glu-5 '/ Glu-3 ', both diagnostic for Northern-Hemisphere M. edulis and M. galloprovincialis , were used to further characterize the nuclear genomes of M. edulis from Kerguelen and M. galloprovincialis from Tasmania. Genomic reticulation was observed, with typical M. edulis allelomorphs fixed in both populations at locus mac-1 whereas, at locus Glu-5 '/ Glu-3 ', allelomorphs characteristic of M. galloprovincialis were present in Kerguelen and nearly fixed in Tasmania. Kerguelen mussels had a genome of mixed M. edulis and M. galloprovincialis ancestry without evidence of barriers to merging as shown by Hardy–Weinberg and linkage equilibrium. Tasmanian mussels possessed a predominantly M. galloprovincialis genomic background introgressed by M. edulis allelomorphs at locus mac-1 . Genetic drift superimposed on ancient hybridization and introgression may explain the genomic reticulation observed in both Kerguelen and Tasmanian mussels. There was no evidence of a recent introduction of Northern-Hemisphere M. galloprovincialis or M. edulis to Kerguelen or Tasmania.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 747–754.     

Critical Analysis of Eukaryotic Phylogeny: A Case Study Based on the HSP70 Family

Trichomonads, together with diplomonads and microsporidia, emerge at the base of the eukaryotic tree, on the basis of the small subunit rRNA phylogeny. However, phylogenies based on protein sequences such as tubulin are markedly different with these protists emerging much later. We have investigated 70 kDa heat-shock protein (HSP70), which could be a reliable phylogenetic marker. In eukaryotes, HSP70s are found in cytosol, endoplasmic reticulum, and organelles (mitochondria and chloroplasts). In Trichomonas vaginalis we identified nine different HSP70-encoding genes and sequenced three nearly complete cDNAs corresponding to cytosolic, endoplasmic reticulum, and mitochondrial-type HSP70. Phylogenies of eukaryotes were reconstructed using the classical methods while varying the number of species and characters considered. Almost all the undoubtedly monophyletic groups, defined by ultrastructural characters, were recovered. However, due to the long branch attraction phenomenon, the evolutionary rates were the main factor determining the position of species, even with the use of a close outgroup, which is an important advantage of HSP70 with respect to many other markers. Numerous variable sites are peculiar to Trichomonas and probably generated the artefactual placement of this species at the base of the eukaryotes or as the sister group of fast-evolving species. The inter-phyla relationships were not well supported and were sensitive to the reconstruction method, the number of species; and the quantity of information used. This lack of resolution could be explained by the very rapid diversification of eukaryotes, likely after the mitochondrial endosymbiosis.     

Sensing,Threading, Orienting,and Cutting Polymers with Rigid-Rod Pores

This short review describes synthetic pores that are made from rigid-rod molecules and can bind oligo-and polymers such as polyacetylenes, p-oligophenyls, terpenoids, polypeptides, polysaccharides, and oligonucleotides. The spotlight is on recent breakthroughs to image the longtime elusive pore-polymer host-guest complexes as single giant pseudorotaxanes.     

Effects of fertilisation on amino acid mobilisation by a plant‐manipulating insect

1. Phytophagous insects frequently manipulate their host‐plant to improve their immediate environment. This generally implies substantial modifications of host metabolism, and sometimes an alteration of nitrogen allocation within the host‐plant. However, the outcome of plant manipulation on amino acid or protein content can be modulated by environmental factors and host‐plant traits. 2. It was investigated whether the pseudogall induced by the aphid Phloeomyzus passerinii (Signoret) (Aphididae: Phloeomyzinae) in the bark of its host‐plant affects the amino acid content in bark tissues, and whether the strength of the modification is modulated by the fertilisation regime and/or the resistance level of the host‐plant. The development of aphid colonies on a resistant and a susceptible poplar genotype, under three fertilisation regimes, was studied. After the development of colonies, the free and protein‐bound amino acid content of the infested bark were quantified. 3. Fertilisation enhanced poplar growth and increased the free amino acid content of bark tissues. Infestation also triggered accumulations of both free and protein‐bound amino acids in the feeding sites, but in the susceptible genotype only. The increase in amino acid content was more pronounced when fertilisation was low, and fertilisation did not enhance aphid development. 4. In conclusion, infestation by P. passerinii triggers an accumulation of amino acids, but the effect is influenced by both the fertilisation regime and the resistance level of the host‐plant. This suggests that P. passerinii could affect the allocation of nutrients within trees during outbreaks.     

Cytogeography of Gentianaceae–Exaceae in Africa,with a special focus on Sebaea: the possible role of dysploidy and polyploidy in the evolution of the tribe

Unlike other tribes of Gentianaceae, Exaceae have so far received little attention regarding their karyological evolution. Indeed, only 35 chromosome number counts (19 species) have been referenced to date, representing only a negligible fraction of the tribal diversity. In this paper, we performed an intensive chromosome count on material collected in the field (South and central Africa, plus Madagascar), encompassing 155 populations and c. 60 species from four genera of Exaceae, including Exacum, Ornichia, Sebaea and Tachiadenus. Fifty nine species (14 Exacum, one Ornichia, 42 Sebaea and two Tachiadenus) were examined for the first time, revealing a broad set of chromosome numbers (2n = 18, 28, 32, 36, 42, 56) and the occurrence of polyploid systems within Exacum and Sebaea. These results allow us to postulate x = 7, 8 or 9 as possible base chromosome numbers for Exaceae and emphasize the importance of both dysploidy and polyploidy processes in the evolution of the tribe. Finally, chromosome numbers appear to be associated to some morphological or geographical traits, suggesting new systematic combinations and likely active speciation patterns in the group. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 556–566.