Catecholaminergic Neurons in the Nervous System of Neorhabdocoela (Turbellaria(

Mapping of catecholaminergic (CAergic) neurons in the nervous system has been performed in 5 species of turbellarians of the order Neorhabdocoela: in three species of typhloplanides, Mesostoma lingua, Bothromesostoma essenii, and Rhynchomesostoma rostratum, and in two species of Dalyellioida, Castrella truncata and Gieysztoria cuspidata. In spite of an essential diversity of their orthogones, the number of cerebral neurons varies insignificantly: from 4 to 5 pairs at 3 variants of geometry of their arrangement. In the presence of the medial paddle-shaped outgrowth of neuropil, two pairs of anterior cerebral neurons are located on its both sides, while 2 pairs of posterior neurons, in the inferior lateral regions of neuropil. The absence of the medial outgrowth and a stretching of neuropil provided a fan-shaped arrangement of cerebral neurons behind the eyes and on the sides of the pharynx. The three-store arrangement of cerebral neurons is revealed in the presence of a cone-shaped trunk at the anterior end of the body, when all 5 pairs of neurons are connected to each other with longitudinal and transverse processes. The rosette-shaped pharynx is innervated with five pharyngeal nerves, while the barrel-shaped pharynx, with six nerves, each of them with one bipolar neuron. From 2 to 5 pairs of neurons of the L-group were revealed. Homology of the L-group neurons has been confirmed in the order Neorhabdocoela. The total number of CAergic neurons varies from 24 to 29.     

Dioecism of the genusCallicarpa (Verbenaceae) in the Bonin (Ogasawara) Islands

The morphology and function of the flowers of three species of the genusCallicarpa, C. glabra, C. nisnimurae andC. subpubescens, endemic to the Bonin Islands, revealed that all three species were dioecious. Male plants had short-styled flowers with sterile ovaries, while female plants had long-styled flowers with non-germinating inaperturate pollen grains. Such dioecism has never been reported from the family Verbenaceae. This curious sexual system with non-germinating pollen grains may have been maintained as a reward to insect pollinators.     

Lipopolysaccharides (LPS) modulate the metabolism of deoxynivalenol (DON) in the pig

Pigs might be exposed to lipopolysaccharides (LPS) and deoxynivalenol (DON) at the same time, and both toxins are thought to interactively affect the intestinal barrier, the innate immune system, and the xenobiotics metabolism. Hence, we aimed at examining the single and combined effects of both toxins on nutrient digestibility and DON metabolism. For this purpose, barrows (26?±?4 kg) were fed restrictedly either a control diet (CON) or a diet contaminated with 3.1 mg DON/kg (DON) for 37 days. At day 37 of the experiment, pigs were infused intravenously for 60 min either with 100 μg DON/kg body weight (BW) (CON-DON), 7.5 μg LPS/kg BW (CON-LPS, DON-LPS) or a combination of both substances (CON-DON?+?LPS), or physiological saline (CON-CON, DON-CON). Blood samples were collected frequently until 3.25 h before the pigs were sacrificed for bile, liver, and kidney collection. The apparent digestibility of N-free extractives was significantly increased by 1 % when the DON-contaminated diet was fed. The total DON content in blood was significantly higher in endotoxemic pigs (34.8 ng/mL; CON-DON?+?LPS) when compared to the pigs infused with DON alone (18.8 ng/mL; CON-DON) while bile concentrations were not influenced by LPS. DON residue levels in liver and kidney closely reflected the treatment effects as described for blood. In contrast to DON infusion, the LPS challenge resulted in a significantly lower total DON concentration (13.2 vs. 7.5 ng/mL in groups DON-CON and DON-LPS, respectively) when the pigs were exposed to DON through the diet. The conjugation degree for DON in blood and bile was not influenced by treatments. In conclusion, endotoxemic pigs are characterized by higher DON residue levels in blood, liver, and kidney, probably by a compromised elimination.     

Effects of acetylphenylhydrazine (APHZ) on the stromal cells of the bone marrow in rats (in vitro)

The study has been carried out on Wistar rats. The animals were divided into two groups: the control rats received 0.9% saline solution intraperitoneally in there consecutive days. The experimental animals were administered 1% solution of acetylphenylhydrazine (APHZ) intraperitoneally also in three days. Prior to the experiments samples of blood have been collected from tail veins and reticulocyte counts made: the counts had also been determined before the culture of tissue was started. On the fifth day of the primary culture, the morphology and enzymatic activity of the stromal cells of the bone marrow were studied. The cells grown in vitro were cultured by the use of the Eagle's medium enriched with 20% calf serum and L-glutamate. The type of the cells, their number and rate of growth were noted. In the cells the activity of specific esterase as well as acid and alkaline phosphatase was determined. Statistically significant differences between the control and experimental animals were found both in the numbers of stromal cells and in the differences in score values of activity of particular enzymes in various types of cells.     

Variation in the Ichnofauna of the Collio Formation (Lower Permian) in the South-Alpine Region (Northern Italy)

In the Collio Formation (Lower Permian) of the South-Apine region (North Italy) paleobiodiversity consists of tetrapod footprints, invertebrate traces and rarer plants, and is characterized by an absolute poverty of taxa that becomes more acute from the lower to the upper part of the Collio Formation. Regionally, the drop in diversity can be explained by joint tectonic and climatic change; humid evergreen environments became mainly dry. Examination of ichnofossil distribution supports this hypothesis.     

Distribution of sulfhydryloxidase (SOx) immunoreactivity in the testis of the axolotl (Ambystoma mexicanum) (amphibia, urodela)

Immunohistochemical localization of sulfhydryloxidase (SOx) has been examined in the testis of the Axolotl (Ambystoma mexicanum). The urodelan testis contains germ cells in various phases of differentiation from primordial germ cells to mature spermatozoa. SOx immunoreactivity is present in mitochondria of primordial germ cells and primary spermatogonia and declines within the population of secondary spermatogonia, suggesting, that the antibody used to localize SOx may serve to estimate the developmental stage of spermatogonia towards meiosis, since more undifferentiated cells react positively. Intensity of immunostaining increases again in spermatocytes and becomes most intense in early round spermatids correlating on ultrastructural level with an accumulation of numerous mitochondria in that part of the cytoplasm, where the acrosome vesicle is formed. Mature sperm are immunonegative. Additionally, Leydig cells within the glandular tissue are stained by the antibody. Thus the distribution pattern of SOx immunoreactivity principally resembles that in the mammalian testis found during ontogenesis or in the adult seminiferous epithelium. The possible functional significance of mitochondrial SOx in germ cells and Leydig cells is discussed. These results suggest, that the amphibian testis is a model for experimental problems dealing with the investigation of germ cells in various developmental phases including very undifferentiated premeiotic germ cells. The cystic testis may be of value in studying influences of various experimental conditions on varied homogeneous populations of germ cells.     

Role of the microbial community in formation of speleothem (moonmilk) in the Snezhnaya carst cave (abkhazia)

The results of investigation of speleothem (moonmilk) from the Snezhnaya cave (West Caucasus, Abkhazia) are reported. The structure of microbial complexes from moonmilk was investigated by quantitative PCR; strains of culturable microorganisms were isolated and their preferred temperature and carbon sources were determined. Among eubacteria, ~34% belonged to the iron bacteria (Rhodoferax). Most bacterial strains were shown to be facultative psychrophiles with the maximum growth rate at 4°C. The microstructure and elemental composition of moonmilk were investigated using a scanning electron microscope (EVO-40HV, Carl Zeiss) and silicon drift X-ray detector X-MAX 80mm². The visually plastic and homogeneous mass of moonmilk was shown to be highly heterogeneous, containing various microstructures. The elemental composition of some nanostructures depended on the structure of bacterial biofilms. Some loci of the biofilm were found to contain up to 46% (wt/wt) of iron oxides. High calcium content, up to 61.5% (wt/wt), was found only in cubic crystalline structures which were not involved in microbiological processes.     

Convergence of the cyst in cysticercoids (Cestoda,Hymenolepidata) and the tegument in cystacanths (Acanthocephala)

It was shown that despite fundamental differences in the organization of the tegument of cystacanths and the cyst wall of cysticeroids, they have a number of features similar in localization, morphology, terms of formation, and functional value. These include a powerful outer layer of glycocalyx on the surface of the tegument, filling of the distal department with dense substance, and the presence of complicated fibrillar systems. It is supposed that the nature of these particularities is convergent and is determined by the similarity of the life cycles of Hymenolepidata and Acanthocephala.     

Identification of the areas of endemism (AOEs) of the genus Acantholimon (Plumbaginaceae) in Iran

Abstract

This study was conducted to identify areas of endemism for Acantholimon species using parsimony analysis of endemicity (PAE) and to detect endemic species richness of the genus in the region. The results obtained from the two methods used in this study were used in determining the priorities for the conservation of Acantholimon species in Iran. The distribution database of 62 endemic species belonging to this genus was formed by 1250 georeferenced observations in Iran. The study area was divided into 1?×1? grids of operative geographical units (OGUs) and the species?×?area matrix including presence/absence data was created. The endemic species richness was calculated using circular neighborhood with a radius of 50?km in 10?×?10?km² raster cells using DIVA-GIS software. The results of PAE analysis have shown four areas of endemism (AOEs) in Iran. AOE1: including Alborz and Zagros mountains, the mountains of central Iran. AOE2 and AOE3 are located in Khorassan subregion and AOE4 contains parts of western Iran. The map of endemic species richness indicated that the highest number of endemic species occurs in central Alborz region as well as Kerman, Chahar-Mahal and Bakhtiari, and Isfahan provinces.     

Differences in the disposition of trichobothria in the Chernetidae (Pseudoscorpiones)

An analysis of the disposition of trichobothria in all the post-embryonic stages of six British species of Chernetidae, similar to that employed by Gabbutt (1969) in his study of the Neobisiidae, shows that a linear relationship exists between the successive position of named trichobothria. A model, based on growing and non-growing regions gives a good approximation to the data. The results are considered in relation to the use of trichobothrial position as an adult generic or specific character and as a device for separating the nymphs of this family.     

Molecular identification (RAPD) of the eight species of the genus Barbus (Cyprinidae) in the Iberian Peninsula

Random amplified polymorphic DNA (RAPD) analysis has been used to identify the eight Barbus species of the Iberian Peninsula, whose morphological differentiation is difficult. Ten random primers were employed to generate RAPD markers. Different RAPD profiles were observed for the different species. Four species-specific markers were found in B. bocagei , seven in B. comizo , five in B. graellsii , three in B. guiraonis , eight in B. haasi , 13 in B. meridionalis , four in B. microcephalus and four in B. sclateri. Evidence is presented that RAPD markers constitute useful tools for accurate taxonomic identification of Spanish barbels which is one of the first prerequisites in effective conservation programmes.     

The role of the CPNKEKEC sequence in the beta(2) subunit I domain in regulation of integrin alpha(L)beta(2) (LFA-1)

The alpha(L) I (inserted or interactive) domain of integrin alpha(L)beta(2) undergoes conformational changes upon activation. Recent studies show that the isolated, activated alpha(L) I domain is sufficient for strong ligand binding, suggesting the beta(2) subunit to be only indirectly involved. It has been unclear whether the activity of the alpha(L) I domain is regulated by the beta(2) subunit. In this study, we demonstrate that swapping the disulfide-linked CPNKEKEC sequence (residues 169-176) in the beta(2) I domain with a corresponding beta(3) sequence, or mutating Lys(174) to Thr, constitutively activates alpha(L)beta(2) binding to ICAM-1. These mutants do not require Mn(2+) for ICAM-1 binding and are insensitive to the inhibitory effect of Ca(2+). We have also localized a component of the mAb 24 epitope (a reporter of beta(2) integrin activation) in the CPNKEKEC sequence. Glu(173) and Glu(175) of the beta(2) I domain are identified as critical for mAb 24 binding. Because the epitope is highly expressed upon beta(2) integrin activation, it is likely that the CPNKEKEC sequence is exposed or undergoes conformational changes upon activation. Deletion of the alpha(L) I domain did not eliminate the mAb 24 epitope. This confirms that the alpha(L) I domain is not critical for mAb 24 binding, and indicates that mAb 24 detects a change expressed in part in the beta(2) subunit I domain. These results suggest that the CPNKEKEC sequence of the beta(2) I domain is involved in regulating the alpha(L) I domain.     

Mapping the collagen-binding site in the I domain of the glycoprotein Ia/IIa (integrin alpha(2)beta(1))

The I domain present within the alpha2 chain of the integrin alpha(2)beta(1) (GPIa/IIa) contains the principal collagen-binding site. Based on the crystal structure of the alpha2-I domain, a hypothetical model was proposed in which collagen binds to a groove on the upper surface of the I domain (Emsley, J., King, S. L., Bergelson, J. M., and Liddington, R. C. (1997) J. Biol. Chem. 272, 28512-28517). We have introduced point mutations into 13 residues on the upper surface of the domain. Recombinant mutant proteins were assayed for binding to monoclonal antibodies 6F1 and 12F1, to collagen under static conditions, and for the ability to retain adhesive activity under flow conditions. The mutations to residues surrounding the metal ion-dependent adhesion site that caused the greatest loss of collagen binding under both static and flow conditions are N154S in the betaA-alpha1 turn, N190D in the betaB-betaC turn, D219R in the alpha3-alpha4 turn, and E256V and H258V in the betaD-alpha5 turn. Mutation in one of the residues that coordinate the metal binding, S155A, completely lost the adhesive activity under flow but bound normally under static conditions, whereas the mutation Y285F had the converse effect. We conclude that the upper surface of the domain, including the metal ion-dependent adhesion site motif, defines the collagen recognition site.     

Regulation of the pineal melatonin concentration in the rat (Rattus norvegicus) and in the Djungarian hamster (Phodopus sungorus)

1. Rapid changes of melatonin concentration in pineals of rats (Rattus norvegicus) after isoproterenol administration or in the course of a day were accompanied by parallel changes of N-acetyltransferase but not of hydroxyindole-O-methyltransferase activity. 2. In pineals of Djungarian hamsters (Phodopus sungorus) the evening and morning melatonin changes were also parallel with N-acetyltransferase changes. 3. In both species, melatonin concentration during its rise had approached the maximum earlier than N-acetyltransferase reached its highest activity. 4. It is proposed that the N-acetyltransferase rhythm drives the melatonin rhythm both in rats and in Djungarian hamsters; the maximum melatonin production may, however, depend also on hydroxyindole-O-methyltransferase activity and substrate concentration.     

(AGCTG) (AGCTG) (AGCTG) (GGGTG) as the primordial sequence of intergenic spacers: the role in immunoglobulin class switch

The means employed for immunoglobulin heavy chain class switch appears to be no different from that by which meiotic intergenic crossing-overs at accomplished. As with other intergenic spacers, the 5' noncoding sequence of each Ig CH (immunoglobulin heavy chain constant region) gene apparently undergoes unconstrained sequence changes due to randomly sustained base substitutions, deletions, and duplications. Yet, there remains sufficient regional sequence homology between the Ig Cmu 5' noncoding sequence and those of its somatic recombination partners, e.g., Ig C gamma 1, Ig C gamma 2b, Ig C alpha, because each of these 5' noncoding sequences is made of multiple copies in various stages of degeneracy of one primordial 20 base pair-long sequence: (AGCTG) (AGCTG) (AGCTG) (GGGTG).     

Early ossification in the skeleton of the sucker (Catostomus macrocheilus) and the guppy (Poecilia reticulata)

Catostomus macrocheilus, a sucker, and Poecilia reticulata, a live-bearer, are subjected to dissimilar mechanical stresses while most of their bony structures are forming. Osteogenesis occurs in the sucker when it is a free-living larva, whereas in the livebearer it occurs intrafollicularly. The first-formed bones ofboth species are those that meet functional demands and are subjected to the greatest stresses. These are the movable bones associated with the acts of respiration and feeding, and some of the axial bones. The cranial roof is the last to calcify. The primary differences in osteogenesis of the two species, such as in the vertebral column and caudal fin, can be correlated with differences in stress. Surface forces on calcifiable tissue perhapsassist in the deposition of calcium salts.