Lipids of different thallus regions of the brown algaSargassum miyabei from the Sea of Japan

The fatty acid and lipid composition of different parts of the thallus of the brown algaSargassum miyabei was studied. The upper and lower thallus regions markedly differed in amounts ofn-3 polyunsaturated fatty acids (PUFAs), monoenoic fatty acids, phospholipids, and glycolipids. The lower thallus regions were rich in monoenoic fatty acids and phospholipids, while the upper parts had higher levels ofn-3 PUFAs and glycolipids.     

Studies on species of Conidiobolus from India-V

Summary Morphological and cultural studies on two new species ofConidiobolus isolated from plant detritus in India are described.C. terrestris is characterized by mycelium differentiating into chains of hyphal bodies, which in older cultures become thick-walled. The morphological similarity of the fungus to the causal organism of Jorge Lobo's disease in Surinam incited byLoboa loboi and the possibility of that being a species ofConidiobolus are discussed.C. lichenicola isolated from decaying lichens is characterized by a vegetative thallus composed of sinuous, lobate and compacted coralloid mycelial mass. The conidial germination is characteristic and organises the coralloid thallus from the very initial stages.     

ON THE LIFE HISTORY OF MONOSTROMA FUSCUM (POSTELS ET RUPRECHT) WITTROCK1

Results of the study of Monostroma fuscum from Son Juan Island, Washington, fully support the separation of the species M. fuscum from Monostroma sensu Wittrock into a taxon including M. obscurum. It would appear from this and previous studies that the M. obscunim-M. fuscum complex is clearly Ulvacean. The characteristics of the complex include (1) alternation of morphologically similar haploid and diploid generations; (2) production of biflagellate gametes and quadriflagellate zoospores; (3) a uniseriate form in early ontogeny; (4) thallus development progressing through a vesicular stage that, as a result of localized degenerative processes, opens at a size of less than I cm into a monostromatic blade; (5) cells elongated perpendicular to the plane of the thallus and with rotund-truncate ends: (6) a single elongate plastid, thickened at the opposite poles of the cell and thinner in the equatorial region of the cell; (7) a thallus composed of cells with relatively inelastic walls; and (8) discrete discharge pores. The chromosome number of Monostroma fuscum is n =9. The first division of the zoosporangium nucleus is meiosis I.     

Beobachtungen anLempholemma-Arten aus dem Ostalpenraum (Lichenes,Lichinaceae)

The phycobiont of all species ofLempholemma analyzed is attacked by haustoria. The haustoria of these five species ofLempholemma and of two species with unknown apothecium but with a thallus quite similar toLempholemma are described. They show distinct morphological and functional characters which allow species delimitation.

Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.     

The fine structure of motile cells in the generaUlvaria andMonostroma,with special reference to the taxonomic position ofMonostroma oxyspermum (Ulvophyceae,Chlorophyta)

The zoospores and isogametes ofUlvaria obscura var.blyttii, the isogametes ofMonostroma bullosum, and the anisogametes ofM. grevillei have a flagellar apparatus with counterclockwise absolute orientation and terminal caps, and therefore belong to theUlvophyceae. On the basis of the absence or presence of body scales and the morphologies of certain flagellar apparatus components,Ulvaria obscura var.blyttii is retained in theUlvales, whileM. bullosum, M. grevillei andM. oxyspermum are referred to theUlotrichales. Differences in scale morphology, certain flagellar apparatus components, and early thallus ontogeny support the transfer ofM. oxyspermum to the genusGayralia. Mating structures and their positional relationships within the cell are described from the gametes examined. A plasmalemma-associated plaque that may be a degenerate mating structure occurs in someG. oxysperma motile cells.     

Neoholmesia,a new genus of the delesseriaceae (Rhodophyta)

A new genus,Neoholmesia, is established on the basis ofHolmesia japonica (Okamura) Okamura. Neoholmesia that is distributed in the Northern Honshu and Hokkaido, Japan, should be placed in theMembranoptera group described by Kylin because of its apical segmentation of the thallus, and because it differs from the genusHolmesia in that tetrasporangia are found scattered randomly over the surface of the main thallus, and in that it bears carposporangia in chains. Dedicated to Prof. Shoichiro Usami celebrating his sexagenary birthday.     

Die Kultur vonHalicystis parvula (Codiales,Chlorophyta) auf kalkhaltigem Substrat

The vesicular thallus ofHalicystis is generally embedded in crusts of coralline algae by a rhizoidal part. Only in former unsuccessful attempts to elucidate the development ofHalicystis has this fact been regarded as being important. Starting fromDerbesia zoospores, the gametophyteHalicystis was attained in free culture. These vesicles, however, are unlike those of the natural plants in morphological aspect: they develop as a local increase of a rhizoidal filament. To grow into vesicles of natural shape in culture, the zoospores ofDerbesia need a calcareous substratum, e. g. fragments of oyster-shell.     

Geographic and environmental factors controlling life history and morphology inPrasiola stipitata Suhr

Summary The vertical distribution of meiotic and non-meiotic plants, of the spore-formation types, of the presence of filamentous stage and, in some cases, of thallus sizes was analyzed in 57 populations ofPrasiola stipitata, collected on both sides of the Atlantic.A vertical zonation exists within the limits of thePrasiola stipitata belt. In the higher levels there are less or no meiotic plants, the thallus size is smaller and the filamentous (Rosenvingiella-) stage may be present. In the lower levels, the ratio of meiotic plants as well as the size of the thallus increases and the filamentous stage is absent. The distribution of marginal and variegated sporophytes does not present a clear pattern, though the marginal type often seems to prevail in the higher levels and the variegated type in the lower. Seasonality is apparent in the decrease of both thallus size and of the ratio of meiotic plants towards the end of the growth season.On the eastern shores of the Atlantic growth is perennial and meiotic plants are infrequent or absent from about 55° latitude northwards. South of this line growth is seasonal and meiotic plants are abundant. On the western shores of the Atlantic growth is perennial and gametophytes are absent from 44° latitude northwards.Dedicated to my venerated teacher, Prof. Dr.Lothar Geitler, for his 70th birthday.     

Modern freshwater microbial carbonates: thePhormidium stromatolites (tufa-travertine) of southeastern Burgundy (Paris Basin,France)

Summary The relationships of microstructure and vegetal remains, obtained by decalcification, were studied in Modern tufa from Burgundy, in order to try to link a given species with a particular crystal habitus. The edifices have various shapes (coatings on floors; encrusted pebbles, shells, vegetal shoots, mosses; oncolites; hydrodynamically shaped tufts). The biological content is rich in algae and animals, mainly at the proximity of springs, even ifPhormidium incrustatum is the predominant species. It is associated with several species ofGongrosira, Schizothrix, andOocardium stratum, the latter only known by its specific crystallizations. Among the animals, we point the galleries ofPsychomiidae (Trichoptera= Phrygan) larvae. The algae and animals are associated within a “biological felt” (in the sense ofForel, 1901). Some species are encrusted by calcite crystals of typical habitus (micrite:Phormidium incrustatum, Gongrosira andSchizothrix, ssp; sparite:Oocardium andBatrachospermum), and there are very little diagenetic modifications. The fabric results in an alternation of seasonal light laminations composed of juxtaposed bundles ofPhormidium incrustatum α, and dark laminations due to parallel filaments ofPhormidium incrustatum β. The influence of other algal species on shape and the internal fabric of the laminations is negligible.Phormidium incrustatum tufa are common in Western Europe, and probably have some fossil analogue in the Upper Cretaceous and Tertiary; the strongly differ from most older stromatolitic microstructures. Half of the studied tufa can suffer summer exposure and winter frost but related particular features do not seem to be preserved in the stromatolitic edifices.     

Attenuation of water velocity and incident light as a function of shape parameters inGracilaria

Characteristic shape parameters, light intensities and relative water velocities were estimated in thalli of free-moving seaweeds, using threeGracilaria-like species:G. cornea, G. conferta andGracilariopsis lemaneiformis. Relative velocities over the branches were determined mostly by rotation of the algae in the water as opposed to linear translation. The tree major shape parameters of the thallus, weight, volumetric specific weight and areal specific weight, explain the differences in relative velocity. Relative velocities near the center of the thallus were about 50% to 80% of the external velocity. Light intensities at the vicinity of the center ofG. cornea ranged between 60% to 90% of the external light intensity. Light attenuation in the center was proportional to the weight of the thallus. The significance of light and velocity attenuation as a function of shape parameters is discussed.Author for correspondence     

The lichen algaTrebouxia: does it occur free-living?

Recent evidence indicates that the most common photobiont of lichens,Trebouxia, has evolved from the soil algaPleurastrum terrestre. The fewTrebouxia cells that have been seen in unlichenized condition probably were released from asexual propagules or thallus fragments.Trebouxia appears to be a lichenized form ofPleurastrum and does not exist free-living.Dedicated to Prof.Elisabeth Tschermak-Woess on the occasion of her 70. birthday.     

Arthopyrenia endobrya,spec. nov., eine hepaticole Flechte mit intrazellulärem Thallus aus Brasilien

Arthopyrenia endobrya from Southern Brazil is illustrated and described as a new species of lichens. The thallus is composed of filamentous green algae loosely surrounded by fungal hyphae. Both symbionts grow endophytically within the leaf cells of two species ofLejeuneaceae (Hepaticae). The algae and hyphae penetrate the cell walls of the host by means of fine perforations. The ascocarps develop between the leaves and perforate them with their apical region. The classification as a member of the genusArthopyrenia is preliminary.

     

PROCESS AND PATTERN INCLADONIA SUBCERVICORNIS

Morphogenesis of podetia inCladonia subcervicornisis a non-linear, repeating process based upon a pattern of meristem enlargement and division. Variability in mature podetia ofC. subcervicornis, which may appear branched or scyphoid, is the result of variation early in ontogeny. The growth pattern ofC. subcervicornisrepresents a continuum of developmental stages. It is impossible to predict the form of the mature thallus ofC. subcervicornisbecause growth in this species is fluid. The morphology of the mature thallus ofC. subcervicornisis difficult to circumscribe using conventionalCladoniaterminology, because the processes that form the thallus are dynamic and heterogeneous. The meristem shapes that are produced during early ontogeny inC. subcervicornisare relatively simple, and the processes by which they are formed are uncomplicated. Yet podetial form inC. subcervicornisis difficult to interpret.     

Laboratory culture and taxonomy of two species ofDerbesia (Class Chlorophyceae) in Japan

Two species ofDerbesia (Class Chlorophyceae),D. marina andD. tenuissima, have been studied for the purpose of obtaining a better understanding of their morphological details and life histories, using preserved and living specimens as well as laboratory cultures. The life histories of both species were completed in the laboratory, starting from both zoospores and zygotes. Specimens were collected at Asamushi, Aomori-ken, and Shimoda, Shizuoka-ken. Their life history types are fundamentally identical, zoospores giving rise upon germination toa Halicystis-phase, while zygotes grow into aDerbesia-phase. The thallus of theHalicystis-phase which alternates withD. marina is the same as that ofH. ovalis which grows in the northern regions of Japan. On the other hand, the thallus of theHalicystis-phase alternating withD. tenuissima is the same as that ofH. parvula known to occur in the temperate to subtropical regions of Japan. These results coincide with those obtained withD. marina andD. tenuissima in Europe, where the type localities of both species are located. Specimens assignable to these two species were collected at several localities in Japan and, as a result of detailed examination of the morphology, they are believed to be identical with eitherD. marina orD. tenuissima.     

Laboratory culture and taxonomy of two species ofPedobesia (Bryopsidales,Chlorophyceae) in Japan

The morphology ofPedobesia lamourouxii andDerbesia ryukyuensis, both collected in Shimoda and the adjacent areas in central Japan, was studied from field specimens and laboratory cultures. Specimens which had the same morphology as EuropeanP. lamourouxii produced stephanokont zoospores which developed into either prostrate filaments or expanded discoidal thalli similar to those described by Feldmann and Codomier (1974) and Feldmannet al. (1975). Erect filament identical with the thallus found in nature developed directly from prostrate filaments. The specimens which had morphology similar to that ofDerbesia ryukyuensis described by Yamada and Tanaka (1938) also produced stephanokont zoospores which developed similarly to those ofP. lamourouxii. This species is, therefore, a member ofPedobesia, and it is made a new combinationP. ryukyuensis (Yamada et Tanaka) Kobara et Chihara, comb. nov.     

Distribution and development of some Manx epiphyte populations

The success ofElachista fucicola as an epiphyte ofFucus vesiculosus is partly due to its ability to grow on most parts of the host thallus. Its ability to reach reproductive maturity quickly ensures its fitness, even on temporary structures such as receptacles. Epiphyte distribution may also vary with host morphology.Himanthalia elongata is a basiphyte for several tissue-specific epiphytes:Ectocarpus fasciculatus, Elachista scutulata, Herponema velutinum andMyriactula areschougii are exclusive, or almost so, to receptacles. On growing receptacles their specificity extends to conceptacles, which also provide refuges from grazing. Epiphyte abundance in summer is greatest at the upper and lower limits ofHimanthalia distribution, suggesting that basiphytes living under suboptimal conditions are more prone to infestation by epiphytes. 5–10% ofHimanthalia receptacles are thought to persist over winter and so to facilitate the transmission of epiphytes to the following year's crop of receptacles. The distribution ofEctocarpus fasciculatus onLaminaria digitata differs in pattern from that onHimanthalia. The twoEctocarpus populations also differ morphologically, but both have reproductive and developmental, characteristics that are in accord with the ecological cycles of their basiphytes. This characteristic is likely to be an important factor in determining the success of an epiphyte. Success may also be facilitated by epiphyte variability or by possession of a fixed but well-adapted phenotype. The very high incidence of brown algal epiphytes on growingHimanthalia receptacles does not reflect the composition of the surrounding algal vegetation. The possibility that some host-recognition mechanism operates cannot be discounted. Dedicated to Dr. Dr. h. c. Peter Kornmann on the occasion of his eightieth birthday.     

Notes onLaboulbenia stenolophi andLaboulbenia anoplogenii (Ascomycetes, Laboulbeniales)

Laboulbenia stenolophi is reported for the first time from Japan.Stenolophus iridicolor andS. propinquus are added as new hosts. The crowded antheridia and the protruding (bulging) cell IV are characteristic of this fungus, although thalli with an almost normal cell IV sometimes occur.Laboulbenia anoplogenii onAnoplogenius is easily distinguished from what has been calledL. anoplogenii onStenolophus, Astigis, Abacetus andChlaeminus by the following characters: 1) no crowded antheridia can be observed throughout thallus development, but many sterile long branches can be observed instead; 2) cell IV starts to undergo cell division early in thallus development; 3) cell V extends downward to the level of cell VII, rather than extending only as far as the perithecial basal cells; and 4) cell VI is usually longer and extends farther distally than cell III.Anoplogenius is the host genus ofL. anoplogenii and the records from other hosts represent misapplied names.     

常规培养与缺氧条件下BCG菌体内外sRNA的表达检测

近期发现细菌的sRNA在菌体内和菌体外均具有一定的生物学功能.为研究结核分枝杆菌菌体内外sRNA的表达情况,通过分析卡介苗(Bacillus Calmette-Guerin Vaccine,BCG)菌体和外泌体RNA测序结果,采用RT-qPCR法检测常规培养与缺氧条件下BCG菌体内外sRNA相对表达量,分析菌体内外sR...     

ECOLOGY OF CLADOPHORA GLOMERATA (L.) KÜTZ IN SOUTHERN ONTARIO1

Cladophora glomerata (L.) Kütz. was the dominant attached alga in streams and along lake shores in southern Ontario. Maximum production occurred in summer and resulted from 2 short periods of intensive vegetative growth (June and September). Optimum habitat conditions consist of a firm substrate in shallow alkaline water. These conditions are provided by harbor facilities where man-made structures supplement naturally occurring rock outcrops or cobble beaches and where nutrients are available from tributaries draining agricultural and urban land areas. Periodicity appears to be related to temperature; the interval between the 2 periods of intensive growth during warm weather decreases at successively more northern locations. Frequent observation of Cladophora growing at a single stream station revealed that variations in thallus morphology and relative cell dimensions of C. glomerata are greater than has generally been recognized. These variations can be attributed to changes in environmental conditions and events in the annual life cycle of the alga.     

Division patterns in the thallus ofPelvetia compressa embryos and the effects of gravity

Summary The pattern of divisions in the thallus ofPelvetia compressa embryos was determined with respect to the embryonic growth axis. To detect all possible division planes, embryos were viewed from two vantages which permitted observations of (1) the thallus pole and (2) the longitudinal embryonic profile. Following formation of rhizoid and thallus cells by any asymmetrical division transverse to the embryonic axis that is established prior to any divisions, the thallus cell divided twice along the embryonic axis (axial divisions) in orthogonal planes, and then divided transverse to the growth axis. This division pattern produced an eight-cell thallus with four cells in each of two layers. The spatial relation between gravity and the first axial division was investigated, and gravity was found to have little effect on the alignment of this division. The reproducible pattern of divisions in the thallus indicates spatial control of spindle positioning.Abbreviations ASW artificial seawater - AF after fertilization