Chemo- and karyotaxonomic studies on some rhizomatous species of the genusSymphytum (Boraginaceae)

InS. tuberosum subspp.tuberosum andnodosum, S. grandiflorum andS. ibericum the presence of the pyrrolizidine alkaloids lycopsamine, echimidine and symphytine could be demonstrated. The taxonS. tuberosum contains an unknown compound that seems to be specific for this taxon. This compound is not the pyrrolizidine alkaloid anadoline which has previously been reported for this species. It is possibly represented by a peak on GC/MS with a molecular ion peak at m/z 623 (as TMS derivative) and can be used as a chemotaxonomic marker for the speciesS. tuberosum. The pyrrolizidine alkaloid pattern of the two subspecies ofS. tuberosum reinforces the close relationship. Fresh material ofS. tuberosum contained the triterpene isobauerenol, but in herbarium material isobauerenol was lacking. InS. grandiflorum, neither fresh nor dried material contains isobauerenol. In herbarium material ofS. ibericum also no isobauerenol could be found. More extensive chemotaxonomical research is necessary to support the view thatS. abchasicum is more closely related toS. ibericum than toS. grandiflorum.     

Reduced MHC variation in a threatened tuatara species

The relationship between neutral and adaptive genetic diversity is important to understand in assessing the implications of a population bottleneck. Fitness-related genes, such as those of the major histocompatibility complex (MHC), may be influenced by selection, and so retain diversity even when it is lost at neutral markers. We measured MHC class I variation in an archaic reptile species Sphenodon guntheri [North Brother Island (NBI) tuatara], which naturally occurs on one 4 ha island in Cook Strait, New Zealand, and has low levels of microsatellite diversity. MHC variation in S. guntheri was compared with microsatellite DNA variation, and with MHC variation in a large population of Sphenodon punctatus (Cook Strait tuatara) on Stephens Island. The NBI population shows significantly decreased levels of genetic diversity compared with the Stephens Island population. Only three different MHC sequences and three genotypes were found on NBI, compared with 15 sequences and 21 genotypes in a similar sample size from Stephens Island. Two sequences appear to be unique to the NBI population. The assortment of sequence variants into genotypes suggests strong gametic disequilibrium between two MHC class I loci in S. guntheri , and only two haplotypes that were present in Hardy–Weinberg proportions were identified. MHC diversity in NBI tuatara appears to be largely influenced by genetic drift, consistent with a recent population bottleneck. This may compromise the ability of this population to respond to novel disease threats.     

Tissue-Characteristic Expression of Mouse Proteome

The mouse is a valuable model organism for biomedical research. Here, we established a comprehensive spectral library and the data-independent acquisition–based quantitative proteome maps for 41 mouse organs, including some rarely reported organs such as the cornea, retina, and nine paired organs. The mouse spectral library contained 178,304 peptides from 12,320 proteins, including 1678 proteins not reported in previous mouse spectral libraries. Our data suggested that organs from the nervous system and immune system expressed the most distinct proteome compared with other organs. We also found characteristic protein expression of immune-privileged organs, which may help understanding possible immune rejection after organ transplantation. Each tissue type expressed characteristic high-abundance proteins related to its physiological functions. We also uncovered some tissue-specific proteins which have not been reported previously. The testis expressed highest number of tissue-specific proteins. By comparison of nine paired organs including kidneys, testes, and adrenal glands, we found left organs exhibited higher levels of antioxidant enzymes. We also observed expression asymmetry for proteins related to the apoptotic process, tumor suppression, and organ functions between the left and right sides. This study provides a comprehensive spectral library and a quantitative proteome resource for mouse studies.     

Eigenschaften des Elektronentransportsystem von Mitochondrien des Protisten Acanthamoeba castellanii Neff. I. Zum Einfluß von Hemmstoffen auf verschiedene Akzeptorsysteme, getested mit einer modifizierten Thunbergtechnik

ZUSAMMENFASSUNG. Die Reduktionsgeschwindigkeit künstlicher Elektronenakzeptoren wurde mittels einer modifizierten Thunbergtechnik in Gegenwart isolierter Mitochondrien des Protisten Acanthamoeba castellanii Neff photometrisch gemessen. Die mit verschiedenen Elektronenakzeptoren und Atmungsketteninhibitoren gewonnenen Meßergebnisse erlauben uns folgendes Bild von der Konstitution der Atmungskette zu entwerfen: a) Der Elektronentransport läuft mindestens bis zum Cytochrom b /Coenzym Q-Komplex auf zwei verschiedenen Wegen ab. b) Eine Stimulierung sowohl des Succinat-Jodnitrotetrazolium-chlorid als auch des NADH-Ferricyanid Reduktasekomplexes unter dem Einfluß von Antimycin A läßt vermuten, daß in der Atmungskette dieses Protisten gewisse Nebengleise des Elektronentransports besonders gangbar sind.
SYNOPSIS. The reduction of artificial electron acceptors by isolated mitochondria of Acanthamoeba castellanii was measured by a modified Thunberg technic. The results with different electron acceptors and respiratory chain inhibitors suggest the following scheme for the constitution of the respiratory chain: a) the chain is divided into 2 different sequences, at least up to the cytochrome b /coenzyme Q complex. b) As seen from the stimulation of the succinate-iodonitrotetrazolium chloride and NADH-ferricyanide reductase complexes by antimycin A, certain alternate pathways of electron transport become more important than the normal one.     

A Two-Layered Targeting Mechanism Underlies Nuclear RNA Sorting by the Human Exosome

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Microsatellite markers for testing host plant‐related population differentiation in the moth genus Yponomeuta

Nine microsatellite primers were developed for Yponomeuta padellus (Lepidoptera: Yponomeutidae) and tested for their applicability in analysing genetic population structure. Eight of the nine loci were highly polymorphic with on average 11.4 alleles. Cross‐species amplification of the nine primer pairs was tested in five other moth species. Primer pairs amplified in Y. cagnagellus, Y. malinellus, Y. evonymellus, and Y. rorellus but not in Y. sedellus and Plutella xylostella.     

A molecular dynamics study of the stoichiometric complex formed by poly (alpha, L-glutamate) and octyltrimethylammonium ions in chloroform solution.

We present a molecular dynamics simulation at 300 K in explicit solvent environment of chloroform of the stoichiometric complex formed by poly(alpha,L-glutamate) and octyltrimethylammonium ions. We observed that the alpha-helix conformation of the polypeptide chain remains stable during a 2-ns run. The surfactant ions predominantly adopted an extended conformation that is stabilized by favorable interactions with the organic solvent. Analysis of the organization of the surfactant with respect to the polypeptide chain indicated that each octyltrimethylammonium cation was preferentially bound to more than one carboxylate group. It was found that the most populated arrangement was that with the surfactant cations interacting with two carboxylate groups simultaneously.     

A missense mutation in the Capza3 gene and disruption of F-actin organization in spermatids of repro32 infertile male mice

Males homozygous for the repro32 ENU-induced mutation produced by the Reproductive Genomics program at The Jackson Laboratory are infertile, have low epididymal sperm concentrations, and produce sperm with abnormally shaped heads and poor motility. The purpose of the present study was to identify the mutated gene in repro32 mice and to define the structural and functional changes causing infertility and the aberrant sperm phenotype. In repro32/repro32 mice, we discovered a failure to shed excess cytoplasm and disorganization of the middle piece of the flagellum at spermiation, resulting in the outer dense fibers being wrapped around the sperm head within a bag of cytoplasm. Using a candidate-gene approach, a mutation was identified in the spermatid-specific “capping protein (actin filament) muscle Z-line, alpha 3” gene (Capza3). CAPZA3 protein localization was altered in spermatids concurrent with altered localization of a unique CAPZB variant isoform and disruption of the filamentous actin (F-actin) network. These observations strongly suggest the missense mutation in Capza3 is responsible for the mutant phenotype of repro32/repro32 sperm and regulation of F-actin dynamics by a spermatogenic cell-specific CAPZ heterodimer is essential for removal of the cytoplasm and maintenance of midpiece integrity during spermiation in the mouse.     

Segmental mobility of polymers in starch granules at low moisture contents

The objective of this study was to determine the moisture content at which the segmental mobility of polymers within a starch granule is restricted. Common corn, waxy corn and high amylose corn starch samples were equilibrated to a final water activity of 0.15, 0.33, 0.75 or 0.97. The samples were then exposed to iodine vapor for 24 h and the color, absorption spectra and X-ray diffraction patterns were measured. Stained and unstained granules were also viewed under a bright field and polarized light microscope. The results demonstrate that successive local transitions occur within a granule with increasing moisture contents. Furthermore, the data shows that at moisture contents of about 13%, iodine is able to penetrate the granule and the resulting complex disrupts the crystalline arrangement within the granules. The differences in extent of mobility of polymers between different starch types can potentially illuminate differences in starch structure and architecture.     

Unusual DNA binding modes for metal anticancer complexes

DNA is believed to be the primary target for many metal-based drugs. For example, platinum-based anticancer drugs can form specific lesions on DNA that induce apoptosis. New platinum drugs can be designed that have novel modes of interaction with DNA, such as the trinuclear platinum complex BBR3464. Also it is possible to design inert platinum(IV) pro-drugs which are non-toxic in the dark, but lethal when irradiated with certain wavelengths of light. This gives rise to novel DNA lesions which are not as readily repaired as those induced by cisplatin, and provides the basis for a new type of photoactivated chemotherapy. Finally, newly emerging ruthenium(II) organometallic complexes not only bind to DNA coordinatively, but also by H-bonding and hydrophobic interactions triggered by the introduction of extended arene rings into their versatile structures. Intriguingly osmium (the heavier congener of ruthenium) reacts differently with DNA but can also give rise to highly cytotoxic organometallic complexes.