Genetic diversity of durum wheat as determined by AFLP in fluorescence

The DNA of fifteen Italian cultivars of durum wheat (Triticum turgidum L. ssp. durum) were analyzed by in fluorescence amplified fragment length polymorphism (fAFLP) in order to obtain the characteristic fingerprintings of genotypes and assess their genetic relatedness. Among 64 combinations of fluorescence labelled primers, three different combinations were chosen as producing a total of 6630 AFLP fragments, 2277 (34.3 %) of them being polymorphic. By using this fAFLP methodology a DNA fingerprinting of each durum wheat cultivar was generated for genotype identification. Analysis of the genetic relationships show the low variability among durum wheat cultivars.     

Method of clonal micropropagation of different willow species and hybrids

Conditions of cultivation and micropropagation of selected biotypes of five willow species (Salyx dasyclados Wimm., S. caspica Pall., S. triandra L., S. purpurea L., and S. viminalis L.) and two hybrids (×S. acuminata S. and ×S. palustris Host.) were optimized. Data on in vitro propagation of S. caspica, S. triandra, S. purpurea together with hybrids S. acuminata and S. palustris were obtained for the first time. It has been demonstrated that the outcome of cultivation and propagation of willows strongly depends on genotypic peculiarities of initial plants. The optimal terms of isolation and sterilization of single-node segments for obtaining 50–75% of aseptic viable developing cultures were estimated. The nutritive media were selected providing induction of stem development (to 67%), their rooting (to 91%), elongation (to 3–6 cm), and multiplication (propagation coefficient of 4). The designed method (adopted to different genotypes) can be applied for obtaining aseptic in vitro cultures serving as initial plant material for genetic transformation and mass propagation of plants with new agriculturally valuable characteristics which are of interest for construction of bioenergetic plantations and for needs of the paper industry.     

Cortical Plasticity Induced by Spike-Triggered Microstimulation in Primate Somatosensory Cortex

Electrical stimulation of the nervous system for therapeutic purposes, such as deep brain stimulation in the treatment of Parkinson’s disease, has been used for decades. Recently, increased attention has focused on using microstimulation to restore functions as diverse as somatosensation and memory. However, how microstimulation changes the neural substrate is still not fully understood. Microstimulation may cause cortical changes that could either compete with or complement natural neural processes, and could result in neuroplastic changes rendering the region dysfunctional or even epileptic. As part of our efforts to produce neuroprosthetic devices and to further study the effects of microstimulation on the cortex, we stimulated and recorded from microelectrode arrays in the hand area of the primary somatosensory cortex (area 1) in two awake macaque monkeys. We applied a simple neuroprosthetic microstimulation protocol to a pair of electrodes in the area 1 array, using either random pulses or pulses time-locked to the recorded spiking activity of a reference neuron. This setup was replicated using a computer model of the thalamocortical system, which consisted of 1980 spiking neurons distributed among six cortical layers and two thalamic nuclei. Experimentally, we found that spike-triggered microstimulation induced cortical plasticity, as shown by increased unit-pair mutual information, while random microstimulation did not. In addition, there was an increased response to touch following spike-triggered microstimulation, along with decreased neural variability. The computer model successfully reproduced both qualitative and quantitative aspects of the experimental findings. The physiological findings of this study suggest that even simple microstimulation protocols can be used to increase somatosensory information flow.     

Cryptic speciation in the field vole: a multilocus approach confirms three highly divergent lineages in Eurasia

Species are generally described from morphological features, but there is growing recognition of sister forms that show substantial genetic differentiation without obvious morphological variation and may therefore be considered ‘cryptic species’. Here, we investigate the field vole (Microtus agrestis), a Eurasian mammal with little apparent morphological differentiation but which, on the basis of previous sex‐linked nuclear and mitochondrial DNA (mtDNA) analyses, is subdivided into a Northern and a Southern lineage, sufficiently divergent that they may represent two cryptic species. These earlier studies also provided limited evidence for two major mtDNA lineages within Iberia. In our present study, we extend these findings through a multilocus approach. We sampled 163 individuals from 46 localities, mainly in Iberia, and sequenced seven loci, maternally, paternally and biparentally inherited. Our results show that the mtDNA lineage identified in Portugal is indeed a distinct third lineage on the basis of other markers as well. In fact, multilocus coalescent‐based methods clearly support three separate evolutionary units that may represent cryptic species: Northern, Southern and Portuguese. Divergence among these units was inferred to have occurred during the last glacial period; the Portuguese lineage split occurred first (estimated at c. 70 000 bp ), and the Northern and Southern lineages separated at around the last glacial maximum (estimated at c. 18 500 bp ). Such recent formation of evolutionary units that might be considered species has repercussions in terms of understanding evolutionary processes and the diversity of small mammals in a European context.