Mechanical Allodynia Circuitry in the Dorsal Horn Is Defined by the Nature of the Injury

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Golgi apparatus analyzed by cryo-electron microscopy

In 1898, the Golgi apparatus was discovered by light microscopy, and since the 1950s, the ultrastructure composition is known by electron microscopic investigation. The complex three-dimensional morphology fascinated researchers and was sometimes even the driving force to develop novel visualization techniques. However, the highly dynamic membrane systems of Golgi apparatus are delicate and prone to fixation artifacts. Therefore, the understanding of Golgi morphology and its function has been improved significantly with the development of better preparation methods. Nowadays, cryo-fixation is the method of choice to arrest instantly all dynamic and physiological processes inside cells, tissues, and small organisms. Embedded in amorphous ice, such samples can be further processed by freeze substitution or directly analyzed in their fully hydrated state by cryo-electron microscopy and tomography. Even though the overall morphology of vitrified Golgi stacks is comparable to well-prepared and resin-embedded samples, previously unknown structural details can be observed solely based on their native density. At this point, any further improvement of sample preparation would gain novel insights, perhaps not in terms of general morphology, but on fine structural details of this dynamic organelle.     

PARENTAL AGE,GAMETIC AGE,AND INBREEDING INTERACT TO MODULATE OFFSPRING VIABILITY IN DROSOPHILA MELANOGASTER

In principle, parental relatedness, parental age, and the age of parental gametes can all influence offspring fitness through inbreeding depression and the parental effects of organismal and postmeiotic gametic senescence. However, little is known about the extent to which these factors interact and contribute to fitness variation. Here, we show that, in Drosophila melanogaster, offspring viability is strongly affected by a three‐way interaction between parental relatedness, parental age, and gametic age at successive developmental stages. Overall egg‐to‐adult viability was lowest for offspring produced with old gametes of related, young parents. This overall effect was largely determined at the pupa–adult stage, although three‐way interactions between parental relatedness, parental age and gametic age also explained variation in egg hatchability and larva‐pupa survival. Controlling for the influence of parental and gametic age, we show that inbreeding depression is negligible for egg hatchability but significant at the larva–pupa and pupa–adult stages. At the pupa–adult stage, where offspring could be sexed, parental relatedness, parental age, and gametic age interacted differently in male and female offspring, with daughters suffering higher inbreeding depression than sons. Collectively, our results demonstrate that the architecture of offspring fitness is strongly influenced by a complex interaction between parental effects, inbreeding depression and offspring sex.     

A Methodological Framework for the Reconstruction of Contiguous Regions of Ancestral Genomes and Its Application to Mammalian Genomes

The reconstruction of ancestral genome architectures and gene orders from homologies between extant species is a long-standing problem, considered by both cytogeneticists and bioinformaticians. A comparison of the two approaches was recently investigated and discussed in a series of papers, sometimes with diverging points of view regarding the performance of these two approaches. We describe a general methodological framework for reconstructing ancestral genome segments from conserved syntenies in extant genomes. We show that this problem, from a computational point of view, is naturally related to physical mapping of chromosomes and benefits from using combinatorial tools developed in this scope. We develop this framework into a new reconstruction method considering conserved gene clusters with similar gene content, mimicking principles used in most cytogenetic studies, although on a different kind of data. We implement and apply it to datasets of mammalian genomes. We perform intensive theoretical and experimental comparisons with other bioinformatics methods for ancestral genome segments reconstruction. We show that the method that we propose is stable and reliable: it gives convergent results using several kinds of data at different levels of resolution, and all predicted ancestral regions are well supported. The results come eventually very close to cytogenetics studies. It suggests that the comparison of methods for ancestral genome reconstruction should include the algorithmic aspects of the methods as well as the disciplinary differences in data aquisition.     

Purification of a NAD(P) Reductase-Like Protein from the Thermogenic Appendix of the Sauromatum guttatum Inflorescence

A NAD(P) reductase-like protein with a molecular mass of 34.146 ± 34 Da was purified to homogeneity from the appendix of the inflorescence of the Sauromatum guttatum. On-line liquid chromatography/electrospray ionization-mass spectrometry was used to isolate and quantify the protein. For the identification of the protein, liquid chromatography/electrospray ionization-tandem mass spectrometry analysis of tryptic digests of the protein was carried out. The acquired mass spectra were used for database searching, which led to the identification of a single tryptic peptide. The 12 amino acid tryptic peptide (FLPSEFGNDVDR) was found to be identical to amino acid residues at the positions 108–120 of isoflavone reductase in the Arabidopsis genome. A BLAST search identified this sequence region as unique and specific to a class of NAD(P)-dependent reductases involved in phenylpropanoid biosynthesis. Edman degradation revealed that the protein was N-terminally blocked. The amount of the protein (termed RL, NAD(P) reductase-like protein) increased 60-fold from D-4 (4 days before inflorescence-opening, designated as D-day) to D-Day, and declined the following day, when heat-production ceased. When salicylic acid, the endogenous trigger of heat-production in the Sauromatum appendix, was applied to premature appendices, a fivefold decrease in the amount of RL was detected in the treated section relative to the non-treated section. About 40 % of RL was found in the cytoplasm. Another 30 % was detected in Percoll-purified mitochondria and the rest, about 30 % was associated with a low speed centrifugation pellet due to nuclei and amyloplast localization. RL was also found in other thermogenic plants and detected in Arabidopsis leaves. The function of RL in thermogenic and non-thermogenic plants requires further investigation.     

Communication Network Reflects Social Instability in a Wild Siamang (Symphalangus syndactylus) Population

International Journal of Primatology - Long-range signaling, such as acoustic communication, is best understood within the broader context of all potential receivers. Exactly what kind of...     

SPERM WHALES TAGGED WITH TRANSPONDERS AND TRACKED UNDERWATER BY SONAR

Abstract: Two sperm whales tagged with acoustic transponder tags were tracked by sonar during a cruise from 16 to 30 October 1991 in the southeast Caribbean west of Dominica Island. The whales dove to depths of 400–600 m and more, including a dive to 1,185 m and one possibly to 2,000 m. They were tracked for periods of 3–14 h, over distances of 8.5–40 km. The tagged whales were found together four and eight days after tagging, and were tracked simultaneously for 13 h, over 31 km. Whale movements on different days at the surface averaged from 0.68 to 0.82 m/set, with dive descent rates from 0.82 to 1.13 m/set, ascent rates from 0.74 to 1.16 m/set, and horizontal movement during dives from 0.76 to 1.29 m/set. Dives lasted from 18 min to 1 h and 13 min, averaging 33 and 41 min on different days. Every track ended when tag signals became obscured at night by dense biological scatterers concentrated in offshore areas where the whales were diving. Both tagged whales appear to have been males of 15 and 11m, each dominant in different groups; but when together the larger whale was dominant, as evidenced by chases and agonistic vocalizations. The whales did not appear to react to the tags or to the sounds associated with tracking (30, 32, and 36 kHz).     

The design of a new group of angiotensin-converting enzyme inhibitors

Using X-ray and NMR data relating to the conformation of the antihypertensive, angiotensin-converting enzyme inhibitor, captopril, and structure--activity relationships of analogues, it has been possible to postulate with the aid of computer graphics, the orientation of the three functions, the thiol, the terminal carboxyl and the carbonyl group which are involved in binding to the enzyme. Bicyclic mimetics of captopril, with related arrays of these functions, have been designed and synthesized. Compounds with the closest approximation to the array in captopril are the most active inhibitors of angiotensin converting enzyme, in vitro.