Antigenic similarity between the β-subunits of the ATPases of a bacterium,a yeast and a higher plant

Antiserum raised against the β-subunit of wheat (Triticum aestivum) chloroplast ATPase cross-reacts with a 51000 protein located in the membrane fraction of Escherichia coli. The differential solubility of this polypeptide after chloroform treatment of unc⁺ and uncD409 strains indicates that this cross-reacting polypeptide is the bacterial β-subunit of ATPase. Thus a high degree of conservation of antigenic determinant sites exists between a bacterial β-subunit and the β-subunit of a monocot. This conservation also seems to extend to the β-subunit of mitochondrial ATPase of yeast (Saccharomyces cerevisiae).     

Threatened species, a re-evaluation of the status of eight endemic plants of the Gala´pagos

Although still in relatively good condition, the Gala´pagos Archipelago suffers from increasing human pressures. Apart from direct actions like hunting and logging, endemic plants and animals are threatened by introduced species, and in many cases the present status of the populations is not known. The conservation status of eight plant species considered endangered was studied from literature and field surveys and the main threats were determined. Each of the eight species is endemic to only one island but in some cases is also present on nearby islets. Of these eight species, one is considered extinct, one critically endangered, and the others suffer various levels of threat. As in all island systems of the world, the main threats are introduced organisms, both plants and animals. The extinct species probably disappeared owing to invasion by Lantana camara, one of the most aggressively invasive plants of the islands, and the most endangered species is threatened by goats. The remaining species seem to be regenerating well and we can expect positive results from protection efforts. Today, only one of the eight species benefits from a direct protection action.     

Transglycosylation of a β-galactosyl radical, in the course of enzymic hydrolysis of lactose, in the presence of selected polyhydroxyalcohols

Sorbitol, xylitol, erythritol and lactitol were used as the acceptors of galactosyl radicals, in the process of transgalactosylation accompanying the hydrolysis of lactose, conducted with -galactosidase (4.0 ml Lactozym 3000 was added to 430 ml 1.45 M lactose with 0.95 M polyhydroxyalcohols). The following concentrations of galactosyl derivatives of polyols were obtained after hydrolysis for 4 h at 40°C: 0.31 M Gal-erythritol, 0.22 M Gal-xylitol, 0.18 M Gal-sorbitol and 0.14 M Gal-lactitol. A quadruple increase of xylitol content in dry matter of a solution (from 11.5% (w/w) to 44.5% (w/w) brought about a 2.3-fold increase of the product content in the solution (15.2% (w/w) of dry matter).     

A study of the Werewilka Inlet of the saline Lake Wyara, Australia – a harbour of biodiversity for a sea of simplicity

Lake Wyara receives most of its water from Werewilka Creek, with the area between the two forming Werewilka Inlet which is highly variable in area, and salinity and has high habitat heterogeneity. Over 12 years, 84 species of macroinvertebrate were found in the inlet, but only 34 in the lake. Halobiont and halophilic species were the same in each, but there were many fewer salt-tolerant species in the lake and no freshwater species. The latter were excluded by salinity, but habitat homogeneity due to strong wave action in the lake seems to limit many salt-tolerant species to the inlet. Species richness in large saline lakes in inland Australia is limited by salinity, poor speciation opportunities engendered by their episodic nature, and habitat homogeneity.     

Cancer research,a field on the verge of a paradigm shift?

The theoretical framework for the field of cancer research is based on two main principles. The first is that cancer advances in a stepwise manner, with each alteration driving cells further toward a malignant state. Second, to cure cancer we must target only cancer-specific properties. Here, we analyze the birth and propagation of the cancer research paradigm. We believe the current paradigm is immersed in crisis and that the field would benefit from integrating theories within and outside the normal modes of research to compile a new framework, with the hope of faster progress and significantly fewer cancer-related deaths.     

Brumptomyia angelae, a new species of Phlebotominae (Diptera, Psychodidae) of the Atlantic forest of the state of Paraná, Brazil

The male of Brumptomyia angelae, sp. nov., a new species of Phlebotominae (Diptera, Psychodidae) of the Atlantic forest of the state of Paraná, Brazil, is described and illustrated. This new taxon is closely related to Brumptomyia ortizi Martins, Silva & Falc?o 1971, Brumptomyia nitzulescui (Costa Lima, 1932), and Brumptomyia troglodytes (Lutz, 1922). The male genitalia of these three latter species have also been drawn.     

The Proboscis Armature of Turbellaria-Kalyptorhynchia,a Derivative of the Basement Lamina?

The fine structure analysis of the proboscis teeth in the genus Carcharodorhynchus Meixner and of the proboscis hooks in the genus Diascorhynchus Meixner revealed that these structures are not derived from local cuticularizations of the epidermis, but rather are closely associated with the basement lamina of the proboscis sheath epithelium. In Diascorhynchus the hooks are specializations within the basement lamina enclosing the proboscis. The proboscis teeth in Carcharodorhynchus seem to be either an intracellular differentiation within the modified proboscis sheath epithelium or, as in Diascorhynchus , a derivative of the basement lamina. The latter is supported by the finding of similar, dermal teeth clearly derived from the basement lamina in the body wall of several species of the genus Carcharodorhynchus. It appears from this study that most "cutic-ular" differentiations of the body wall in Turbellaria are either derivatives of the basement lamina or of the cytoplasm of the epidermis cells. These considerations are discussed in the light of possible evolutionary pathways leading from a ciliated epidermis (e.g. free-living acoelomates) to a cuticularized hypodermis (e.g. Aschelmimhes and Articulata).     

17-AAG,a Hsp90 inhibitor,attenuates the hypoxia-induced expression of SDF-1α and ILK in mouse RPE cells

The aim of this study was to investigate the changes of SDF-1α and ILK expression in mouse retinal pigment epithelium (RPE) cells in response to hypoxia, and the effect of 17-Allylamino-17-demethoxygeldanamycin (17-AAG), a heat shock protein 90 (Hsp90) inhibitor, on the hypoxia-induced expression of SDF-1α and ILK. RPE cells were cultured with 200 μmol/L cobalt chloride (CoCl₂) for different times (1, 3, 6, 12, 24, 72 h) to imitate chemical hypoxia. Pretreatment of 17-AAG was 1 h prior to hypoxic insult. Cellular viability after 17-AAG treatment was assessed by MTT assay, and the changes of SDF-1α and ILK expression were examined by RT-PCR and Western blot. Up-regulation of SDF-1α and ILK expression in response to hypoxia was observed. One hour pretreatment of 17-AAG could remarkably decreased the hypoxia-induced SDF-1α and ILK expression in vitro. Our results indicated that SDF-1α and ILK involved in the hypoxic response of RPE cells, and 1 h pretreatment of 17-AAG had an inhibitive effect on the hypoxia-induced SDF-1α and ILK expression.     

Ultrastructure of the endocrine cell types in the adenohypophysis of the teleost,Poecilia latipinna — a morphometric model

Summary A morphometric model providing detailed quantitative information on the ultrastructure of the adenohypophysial endocrine cells has been developed for Poecilia latipinna. The model consists of various morphological components quantified in terms of volumes, surfaces or numbers. For prolactin and growth hormone cells, appropriate results are expressed relative to the average volume of that cell type. The difficulties of quantifying EM data on pituitary glands, together with the various sources of error to which the data are clearly open, have been discussed. Some practical applications of quantitative EM to problems in fish pituitary research are outlined.I thank Dr. J.N. Ball for supplying the fish and Mr. L. Ethridge for technical assistance.     

DA-Raf,a dominant-negative antagonist of the Ras–ERK pathway,is a putative tumor suppressor

Activating mutations of RAS genes, particularly KRAS, are detected with high frequency in human tumors. Mutated Ras proteins constitutively activate the ERK pathway (Raf–MEK–ERK phosphorylation cascade), leading to cellular transformation and tumorigenesis. DA-Raf1 (DA-Raf) is a splicing variant of A-Raf and contains the Ras-binding domain (RBD) but lacks the kinase domain. Accordingly, DA-Raf antagonizes the Ras–ERK pathway in a dominant-negative fashion and suppresses constitutively activated K-Ras-induced cellular transformation. Thus, we have addressed whether DA-Raf serves as a tumor suppressor of Ras-induced tumorigenesis. DA-Raf(R52Q), which is generated from a single nucleotide polymorphism (SNP) in the RBD, and DA-Raf(R52W), a mutant detected in a lung cancer, neither bound to active K-Ras nor interfered with the activation of the ERK pathway. They were incapable of suppressing activated K-Ras-induced cellular transformation and tumorigenesis in mice, in which K-Ras-transformed cells were transplanted. Furthermore, although DA-Raf was highly expressed in lung alveolar epithelial type 2 (AE2) cells, its expression was silenced in AE2-derived lung adenocarcinoma cell lines with oncogenic KRAS mutations. These results suggest that DA-Raf represents a tumor suppressor protein against Ras-induced tumorigenesis.     

Cytogenetic biomonitoring of inhabitants of a large uranium mineralization area: the municipalities of Monte Alegre, Prainha, and Alenquer, in the State of Pará, Brazil

Uranium is a natural radioactive metallic element; its effect on the organism is cumulative, and chronic exposure to this element can induce carcinogenesis. Three cities of the Amazon region—Monte Alegre, Prainha, and Alenquer—in North Brazil, are located in one of the largest uranium mineralization areas of the world. Radon is a radioactive gas, part of uranium decay series and readily diffuses through rock. In Monte Alegre, most of the houses are built of rocks removed from the Earth’s crust in the forest, where the uranium reserves lie. The objective of the present work is to determine the presence or absence of genotoxicity and risk of carcinogenesis induced by natural exposure to uranium and radon in the populations of these three cities. The frequency of micronuclei (MN) and chromosomal aberrations (CA) showed no statistically significant differences between the control population and the three study populations (P > 0.05). MN was also analyzed using the fluorescence in situ hybridization (FISH) technique, with a centromere-specific probe. No clastogenic and/or aneugenic effects were found in the populations. Using FISH analysis, other carcinogenesis biomarkers were analyzed, but neither the presence of the IGH/BCL2 translocation nor an amplification of the MYC gene and 22q21 region was detected. Clastogenicity and DNA damage were also not found in the populations analyzed using the alkaline comet assay. The mitotic index showed no cytotoxicity in the analyzed individuals’ lymphocytes. Once we do not have data concerning radiation doses from other sources, such as cosmic rays, potassium, thorium, or anthropogenic sources, it is hard to determine if uranium emissions in this geographic region where our study population lives are too low to cause significant DNA damage. Regardless, genetic analyses suggest that the radiation in our study area is not high enough to induce DNA alterations or to interfere with mitotic apparatus formation. It is also possible that damages caused by radiation doses undergo cellular repair.     

Hsüa robusta,a new land plant from the Lower Devonian of Yunnan,China

A new psilophytic plant, Hsüa robusta, is found in the Xujiachong Formation (Emsian) of the Lower Devonian from the Qüjing (= Kütsing) district of Yunnan, China. This plant is tentatively referred to the Cooksoniaceae of Rhyniales. Hsüa gen. nov. Type species: Hsüa robusta (Li et Cai) C. S. Li. Diagnosis: Plants erect and then creeping. Main axes dividing pseudomonopodially and bearing dichotomous lateral branches which somewhat differentiate into vegeta, tire and fertile ones, with dichotomous root-like and rhizophore-like appendages. Sporangia terminal, round to reniform or wide reniform, dehiscing along distal margin into two equal halves. Spores homosporous, trilete. Stomata anomocytic. Protostele centrarch. Hsüia robusta (Li et Cai) C. S. Li, comb. nov. Cooksonia zhanyiensis Li et Cai, Acta Geologica Sinica, 52 (1) 1978, p. 10, pl. II, fig. 6.——Taeniocrada robusta Li et Cai,ib. p. 10, pl. II, fig. 7—14. Diagnosis: Characters same as in generic diagnosis. Main axes 6—10 mm wide and at least 24 cm long, with vascular strands 1.2—2.4 mm acr oss. Fertile branches 3—4 times equally or unequally dichotomous, 10—1.5 mm in width and up to 11 cm in length, possessing a vascular bundle of 0.5 mm in its greatest diameter. Branches circinately coiled in apical regions. Axial tubercles, root-like and rhizophore— like appendages arising from the main axes usually anterior to the lateral branches. Axial tubercle round with a diameter of 2.2—2.4 mm, having a vascular bundle about l mm across. Rootlike branches 3 times bifurcate, 1—0.3 mm wide and up to 1.5 cm long, with a vascular bundle about 0.1 mm across. Rhizophore-like appendages forked, 3—1.7 mm in width, possessing a vascular bundle of 0.7 mm in its greatest diameter. Root-like protuberances sometimes arising from rhilzophore-like branches. Epidermal cells of axes generally elongate, measuring 60—290μby 25—60 μ. Stomata mainly fusiform, 90—110 μ long and 50—60μ wide, consisting of a pair of guard cells enclosing a pore 6—15μ in length and 1—3μ in width. Cuticle of guard cells quite thick. Stomatal density about 5 per mm². Sporangia 0.8—4.2 mm high, 1.0—8.2 mm across, usually having a dehiscent distal border which measures 50—100μ broad. Demarcation between sporangium and its stalk quite clear. Epidermal cells of basal part of sporangial walls elongate, about 100 μ long and 30μ wide, but those of distal part isodiametrally polygonal, about 50μ in diameter. Stomata, radially arranged scattering over sporangial walls, generally round about 50μ in diameter and 50 per sporangium. Spores round, 18—36μ (average 27μ) indiameter, and smooth. Tracheids of protoxylem about 10μ across; those of metaxylem about 30μ across, with scalariform thickening. This plant is similar to Renalia hueberi Gensel in general morphology, but differs from the latter in possessing root-like and rhizophore-like branches. The generic name is derived from Prof. Hsü Jen. This paper is a thesis for M. Sc.     

S-Glutathionylation of the Na,K-ATPase Catalytic α Subunit Is a Determinant of the Enzyme Redox Sensitivity

Na,K-ATPase is highly sensitive to changes in the redox state, and yet the mechanisms of its redox sensitivity remain unclear. We have explored the possible involvement of S-glutathionylation of the catalytic α subunit in redox-induced responses. For the first time, the presence of S-glutathionylated cysteine residues was shown in the α subunit in duck salt glands, rabbit kidneys, and rat myocardium. Exposure of the Na,K-ATPase to oxidized glutathione (GSSG) resulted in an increase in the number of S-glutathionylated cysteine residues. Increase in S-glutathionylation was associated with dose- and time-dependent suppression of the enzyme function up to its complete inhibition. The enzyme inhibition concurred with S-glutathionylation of the Cys-454, -458, -459, and -244. Upon binding of glutathione to these cysteines, the enzyme was unable to interact with adenine nucleotides. Inhibition of the Na,K-ATPase by GSSG did not occur in the presence of ATP at concentrations above 0.5 mm. Deglutathionylation of the α subunit catalyzed by glutaredoxin or dithiothreitol resulted in restoration of the Na,K-ATPase activity. Oxidation of regulatory cysteines made them inaccessible for glutathionylation but had no profound effect on the enzyme activity. Regulatory S-glutathionylation of the α subunit was induced in rat myocardium in response to hypoxia and was associated with oxidative stress and ATP depletion. S-Glutathionylation was followed by suppression of the Na,K-ATPase activity. The rat α2 isoform was more sensitive to GSSG than the α1 isoform. Our findings imply that regulatory S-glutathionylation of the catalytic subunit plays a key role in the redox-induced regulation of Na,K-ATPase activity.     

Occurrence of a Putative Precursor to the Amyloplast,the “Amyloplast Initial” in Developing Stolons of the Potato

Cells at the apical part of developing stolons of the potato (Solatium tuberosum L. cv. Norin 1) were analyzed for the occurrence of putative precursors to amyloplasts, designated “amyloplast initial.” Ultrastructural studies showed that the cells contained the expected novel organelle. It was about 1 μm in diameter, devoid of thylakoid membranes, and was stained to a similar extent as the stroma of amyloplasts by uranyl acetate and lead citrate. Formation of thylakoid membranes and starch granules takes place at an early stage of development of these initials when they are just a few μm in diameter. At this stage, proliferation of the initials takes places by division at random sites.     

In Celebration of the Publication of a New Mycological Journal from Jilin,China

The 2 4thvolumeofJOURNALOFJILINAGRICULTURALUNIVERSITYwaspublishedinFebruary 2 0 0 2asmemorialissueofthelateProf.ZHOUZong huangatJilinAgriculturalUniversity .Inthisissueatotalof34myco logicalandphytopathologicalpaperswasreported ,aswellasadetailedintroductiontothescientificcareerandachievementsofProf.ZHOU .ThetopicsandtitlesofthepapersherewellrepresentrecenttrendsandprogressinthesefieldsofstudyinChina .MycologistsinAsiahavebeenconcernedwithmycologicalinformationfromChina .…     

Is the effect of priming plants,and a functional JAR1, negligible on the foraging behaviour and development of a generalist lepidopteran,Helicoverpa armigera?

Theory and recent literature suggest strong effects of induced plant defences in some plant herbivore systems. Few have studied behavioural effects on intact plants. Differences in foraging behaviour as well as weight gain were determined for first instar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on Arabidopsis thaliana (L.) Heynh. (Brassicaceae) mutant and wild type plants, non‐primed, or primed by herbivore feeding or methyl jasmonate. The differences in feeding were primarily in the length of feeding time as opposed to the area fed on, feeding location, or frequency. More larvae dispersed from plants after priming by mite feeding than dispersed after caterpillar feeding. Other behavioural activities such as resting were not significantly affected. Early instars gained less weight feeding on ein2 (ethylene insensitive) mutant, but there was no difference in weight gain between larvae feeding on induced and non‐induced plants of the same type. We concluded that there are fitness consequences for neonates of the generalist H. armigera after feeding on induced plant tissues in some cases, and that distinct changes in behaviour are recognisable both at the fine scale and at grosser levels (dispersal). However, these changes are more subtle than might be expected.     

Patterns of richness and endemism of the Mexican herpetofauna,a matter of spatial scale?

The goal of this study was to compare the richness and endemism patterns of Mexican species of amphibians and reptiles at different spatial scales. We used the best available dataset of distributional ranges generated from ecological niche models and employed geographically weighted regressions (GWRs) to test whether richness and endemism were related. Patterns were found to vary with the scale used for richness and endemism, and these patterns were not coincident. The results showed that: (1) only relatively coarse spatial scales can address latitudinal patterns in amphibians and reptiles, and, in fine scales, they are related to topographic formations; (2) areas of greatest endemism for amphibians and reptiles are located in the highlands of the central or southern part of the country, although not necessarily in the same specific highlands for both groups; (3) there is a strong average correlation between richness and endemism for both groups, indicating that the same factors contribute to both patterns, but these factors act differentially in terms of regions among amphibians and reptiles; and (4) the scale at which the analysis is conducted is important, and we believe that careful consideration of spatial scale must be undertaken to avoid false conclusions. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 305–316.