Phylogenetic Relationships Among Microsporidia Based on rDNA Sequence Data, With Particular Reference to Fish-Infecting Microsporidium Balbiani 1884 Species.

Recently, large discrepancies have been identified between microsporidian systematics based on molecular and traditional characteristics. In the current study the 530f-580r region of the rRNA gene of eight microsporidian species was cloned and sequenced. Included were two unclassified species of Microsporidium Balbiani, 1884 and an unidentified microsporidian that infects the musculature of different sea bream species. Sequence identities in excess of 98% indicated that these three species almost certainly are members of the same genus. Phylogenetic analyses of all microsporidian sequence data available for this region of the gene (20 species) and for partial small subunit sequences (51 species of 21 genera) revealed these species to be distinct from the family Pleistophoridae Doflein, 1901 and closely related them to the genus Sproguea Weissenberg, 1976. This clade was found to comprise a sister taxon to that containing the vast majority of fish-infecting species. Broad cladistic divisions were found between terrestrial insect-infecting and fish-infecting species, which together are distant from the aquatic insect-infecting microsporidia. The rRNA gene of certain fish-infecting genera was found to be more highly conserved than previously reported. This has implications for its utility in diagnostic assays and phylogenetic studies at, or close to, the species level.     

STIMULATION OF COLLAGEN SYNTHESIS IN RAT CARDIAC FIBROBLASTS BY EXPOSURE TO HYPOXIC CULTURE CONDITIONS AND SUPPRESSION OF THE EFFECT BY NATRIURETIC PEPTIDES

Synthesis of type I and type III collagens by rat cardiac fibroblasts was stimulated when the cells were cultured under 95% N₂/5% CO₂for one hour followed by incubation under normoxic conditions for 24 hours. The stimulative effect was attenutated by the presence of atrial natriuretic peptide (ANP, 10⁻⁶m) or brain natriuretic peptide (BNP, 10⁻⁶m) in the culture medium. Northern blot analysis indicated that α1(I) and α1(III) collagen mRNA levels were also increased by hypoxia, and decreased with the addition of ANP or BNP in a dose-dependent manner. These results indicate interaction between intracellular signals of a physical stimulus (hypoxic stress) and those of a chemical one (ANP or BNP) and demonstrate that both signals regulate collagen synthesis by cardiac fibroblasts at the levels of the mRNAs. The results also suggest that natriuretic peptides produced by cardiomyocytesin vivomay function as paracrine factors that play a role in the prevention of cardiac fibrosis in ischaemic heart diseases.     

Studies on peroxidase isolated from etiolated Alaska pea seedlings I. General properties

Two kinds of peroxidase were isolated chromatographically frometiolated Alaska pea seedlings. One had absorption maxima at421 and 530 mµ, and the other, at 405, 500 and 640 mµ.From their affinities for cyanide and migrating patterns onelectrophoresis, the latter was concluded to be a modified formof the former. They were named peroxidase b and b', respectively.Both oxidized IAA, the optimal pH value for the reaction being3.0. (Received April 20, 1970; )     

A STUDY ON INCREASE IN O-DIPHENOL OXIDASE ACTIVITY DURING INCUBATION OF SLICED SWEET POTATO TISSUE

The increase in o-diphenol oxidase activity and polyphenol contentwas investigated in slices excised from sweet potato roots.o-Diphenol oxidase activity increased in a sigmoidal fashionover a 100 hour period. The increase in polyphenols occurredover a shorter period of time and was evident before an increasein o-diphenol oxidase activity could be detected. Thus, it seemedthat the increase in polyphenol content might be involved inthe enhancement of o-diphenol oxidase activity. However, theabove correlation was not found in different kinds of experimentincluding pretreatment with either vacuum infiltration or wetconditioning. (Received October 14, 1965; )     

Centripetal Disposition of Bundle Sheath Chloroplasts During the Leaf Development of Eleusine coracana

Distribution of chloroplasts in bundle sheath cells was examinedby light and electron microscopy during the leaf developmentof finger millet (Eleusine coracana Gaertn.), an NAD malic enzymetype C₄ plant with centripetal arrangement of bundle sheathchloroplasts. Young chloroplasts are almost evenly distributedalong the cell walls in bundle sheath cells of folded immatureleaves. In elongating leaves and above the elongation zone thebundle sheath chloroplasts tend to lie along the radial wallsand the walls adjacent to the vascular bundle. They furthermigrate near to the vascular bundle and finally establish acentripetal arrangement. Mitochondria, microbodies and nucleusmigrate along with the chloroplasts. Etioplasts and other organellesare centripetally located in the bundle sheath cells of etiolatedseedlings grown in the dark. Bundle sheath chloroplast, C₄ plant, chloroplast, chloroplast orientation, Eleusine coracana, finger millet     

On linking multiyear biometric measurements of tree growth with eddy covariance-based net ecosystem production

Annual measurements of the diameter growth and litter fall of trees began in 1998 using a 1.0 ha permanent plot beneath a flux tower at the Takayama flux site, central Japan. This opened up an opportunity for studies that compare the interannual variability in tree growth with eddy covariance-based net ecosystem production (NEP). A possible link between multiyear biometric-based net primary production (NPP) and eddy covariance-based NEP was investigated to determine the contribution of autotrophic production and heterotrophic respiration (HR) to the interannual variability of NEP in deciduous forest ecosystems. We also defined the NEP^* as the measurable organic matter stored in an ecosystem during the interval in which soil respiration (SR) measurements were taken. The difference of biometric-based NEP^* from eddy covariance-based NEP within a given year varied between 55% and 105%. Woody tissue NPP (stems and coarse roots) varied markedly from 0.88 to 1.96 Mg C ha⁻¹ yr⁻¹ during the 8-year study period (1999–2006). Annual woody tissue NPP was positively correlated with eddy covariance-based NEP ( r ²=0.52, P <0.05). However, neither foliage NPP ( r ²=0.03) nor HR ( r ²=0.06) were correlated with eddy covariance-based NEP. Therefore, it was hypothesized that interannual variability in the ecosystem carbon exchange was directly responsible for much of the interannual variation in autotrophic production, especially carbon accumulation in the woody components of the ecosystem. Moreover, similar interannual variations of biometric-based NEP^* and eddy covariance-based NEP with small variations in SR and foliage NPP suggest a constant net accumulation of carbon in nonliving pools at the Takayama site.     

Anaerobic ATP Levels in the Blue-Green Alga Anabaena: Dark-Light Transients and Effects of Light Intensity

An enzymatic method was used to determine ATP extracted from anaerobically incubated samples of the blue-green alga Anabaena variabilis. The dark-light-dark transients of the ATP level in the whole cells were studied in the presence and in the absence of 3 (p-chlorophenyl)-l.l-dimethylurea (CMU). When O₂ evolution was completely inhibited by CMU, there was no significant difference between the transient under illumination of a low intensity and that of fourfold intensity. On the other hand in the absence of CMU, the ATP level decreased more rapidly after high intensity illumination than after low intensity one. The increase in ATP content during the first 5 s illumination was smaller in the absence of CMU than in the presence of CMU. With or without CMU the increase was saturated at the vicinity of the intensity at which photosynthetic O₂ evolution compensates for respiratory O₂ consumption. The calculated quantum requirement of cyclic photophosphorylation in vivo was 2.2 quanta per ATP.     

World revision of Dolichocolon Brauer & Bergenstamm (Diptera: Tachinidae: Exoristinae: Goniini)

The Palaeotropical goniine genus Dolichocolon Brauer & Bergenstamm is revised and analysed cladistically. Seventeen new species are described from Australia (Queensland, Northern Territory), Cameroon, China, the Democratic Republic of Congo, Ethiopia, Japan, Papua New Guinea, Senegal, Thailand, Uganda, Yemen, and Zimbabwe. The following new synonymy is proposed after direct comparison of primary types: Dolichocolon klapperichi Mesnil, 1967 = Dolichocolon orientale Townsend, 1927 syn. nov. A key to the 21 known species is presented. A cladistic analysis based on 36 morphological characters provides support for the monophyly of Dolichocolon. A sister‐group relationship is indicated between Dolichocolon and Kuwanimyia Townsend, whereas Dolichocolon chiangmaiensis sp. nov. from Thailand takes a position as sister group to all other Dolichocolon species. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 544–584.     

Consequences of forest fragmentation in an understory plant community: extensive range expansion of native dwarf bamboo

Understory bamboo species are important and influential components of temperate forests in at least several parts of the world. Here we report a study testing the effect of forest fragmentation on the dynamics of the dwarf bamboo Sasa chartacea and on forest herb communities in the Tokachi plain of Hokkaido, Japan. We studied 16 forest fragments of different sizes and small plots established in these fragments to examine the relationship between the abundance of S. chartacea, landscape and environmental conditions, and forest herb communities. Sasa chartacea was more abundant near forest edges and in smaller fragments, suggesting that the species has expanded its local range and increased its abundance in response to forest fragmentation. Edge‐related changes in light and soil moisture might have facilitated this range expansion. The species richness of forest herbs was strongly negatively related to the density of S. chartacea. Because much larger variation in species richness was explained by S. chartacea density than distance to the nearest forest edge, the expansion of S. chartacea has likely excluded other understory species by competition. In addition, the density of S. chartacea significantly explained variation in the species composition of forest herbs across plots. Taken together, our results emphasize the key roles of dwarf bamboos in changing plant communities following forest fragmentation.