Different fates of the chloroplast tufA gene following its transfer to the nucleus in green algae

Previous work suggested that the tufA gene, encoding protein synthesis elongation factor Tu, was transferred from the chloroplast to the nucleus within the green algal lineage giving rise to land plants. In this report we investigate the timing and mode of transfer by examining chloroplast and nuclear DNA from the three major classes of green algae, with emphasis on the class Charophyceae, the proposed sister group to land plants. Filter hybridizations reveal a chloroplast tufA gene in all Ulvophyceae and Chlorophyceae, and in some but not all Charophyceae. One charophycean alga, Coleochaete orbicularis, is shown to contain an intact but highly divergent chloroplast tufA gene, whose product is predicted to be nonfunctional in protein synthesis. We propose that a copy of the tufA gene was functionally transferred from the chloroplast to the nucleus early in the evolution of the Charophyceae, with chloroplast copies of varying function being retained in some but not all of the subsequently diverging lineages. This proposal is supported by the demonstration of multiple tufA-like sequences in Coleochaete nuclear DNA and in nuclear DNA from all other Charophyceae examined

La vegetació aquàtica submergida de S'Albufera de Mallorca

Al segle passat, i amb l'objectiu de dessecar S'Albufera, s'enturaren estanys i es construí un sistema de canals que condueixen les aigües de forma regular cap a la mar: la majoria d'estanys del que actualment es parc natural quedaren dessecats. Actualment S'Albufera és un gradient ambiental amb diferents aportaments d'aigua. Consequentment, hi ha una diversitat d'hàbitats colonitzats per moltes espècies i és un lloc ideal per als estudis de les toleràncies ambientals de les espècies. S'estudiaren onze espècies de carofícies i deu de plantes vasculars submergides, respecte a set variables ambientals mitjançant un test de significació. Se n'obtingué una visió global mitjançant una anàlisi de components principals per a variables, les quals formen l'espai multidimensional on s'han projectat els hàbitats físico-químics de les espècies. D'aquesta anàlisi es poden extreure conclusions sobre les preferències d'hàbitat de les espècies, Nitellopsis obtusa, Tolypella glomerata, Chara globularis, C. connivens i C. aspera apareixen en aigües mesohalines, mesotròtiques 0 oligotròfiques. C. major i C. vulgaris accepten un cert nivell d'eutrofia i C galioides, C. hispida i C. canescens es presenten en llocs amb nivells baixos d'eutròfia. Lamprothamnium papulosum ocupa llocs altament salinitzats i poc eutrofitzats. A l'àrea d'estudi i en referència als paràmetres estudiats es pot dir que C. canescens, C. globularis, C. vulgaris, Tolypella glomerata, Lamprothamnium papulosum, C. hispida i C. galioides són espècies amb una tolerància global àmplia i C. connivens, Nitellopsis obtusa i C. major són molt menys tolerants. Myriophyllum spicatum, Najas marina, Potamogeton crispus, P. pectinatus i Zannichellia pedunculata són espècies àmpliament distribuïdes a S'Albufera. Ceratophyllum submersum i Ruppia maritima var. brevirrostris s'han de considerar estenoiques dins l'ambient d'estudi. La tolerància de Ceratophyllum submersum a la salinitat es significativament baixa mentre que la de Ruppia cirrhosa i R. maritima var. brevirrostris significativament alta. Ceratophyllum submersum té una distribució significativament negativa respecte a les altes concentracions de clorofil·la a fitoplanctònica i a les altes concentracions de fosfats. Ceratophyllum demersum i C. submersum es presenten principalment als llocs rics amb composts de nitrogen, mentre que Ruppia cirrhosa es presenta en llocs on hi ha baixes concentracions de nitrats a l'aigua.In the last century and with the aims of dessication of the S'Albufera were filled up many lagoons and a canal system was made. Now the S'Albufera is a graded system of coastal marshes with several sources of water input. Consequently there is a diversity of habitats colonized by many species and it is an ideal site for the study of environmental tolerances. Eleven species of Characeae and ten species of submerged vascular plants have been analyzed for seven environmental variables by means of a significance test. A synthetic view has been obtained through a principal component analysis for variables which form the multidimensional space where we project the species physico-chemical habitat. From such analysis we can obtain conclusions on the relative habitat preferences of the Characeae and of the submerged vascular plats of the S'Albufera. Nitellopsis obtusa, Tolypella glomerata, Chara globularis, C. connivens and C. aspera appear in mesohaline and mesotrophic or oligotrophic zones. C. major and C. vulgaris accept some degree of eutrophy and C galioides, C. hispida and C. canescens low levels of eutrophy. Lamprothamnium papulosum appears over strongly salinized sites which are poorly eutrophied. In the study area and in relation to parameters under study, we regard C. canescens, C. globularis, C. vulgaris, Tolypella glomerata, Lamprothamnium papulosum, C. hispida and C. galioides as species with a wide global tolerance and C. connivens, Nitellopsis obtusa and C. major as being decreasingly tolerant. Myriophyllum spicatum, Najas marina, Potamogeton crispus, P. pectinatus and Zannichellia pedunculata are widely distributed in the S'Albufera. Ceratophyllum submersum and Ruppia maritima var. brevirrostris are considered stenoic. The tolerance of Ceratophyllum submersum to salt is significantly low and that of Ruppia cirrhosa and R. maritima var. brevirrostris significantly high. Ceratophyllum submersum has a significantly negative distribution with regard to phytoplanctonic chlorophyll a and phosphate concentrations. Ceratophyllum demersum and C. submersum primarily occur in nitrate-rich waters whereas Ruppia cirrhosa primarily occurs in low nitrate waters

Floristic records: the Characeae of NE of Minorca Island

Abstract not availabl

A reassessment of Geminella (Chlorophyta) based upon photosynthetic pigments, DNA sequence analysis and electron microscopy

A cultured microalgal strain (UTEX 2540) originally identified as Heterotrichella gracillas Reisigl (Xanthophyceae) was re-examined using various techniques. Morphological evidence, particularly the absence of dimorphic cells (one blunt, the other tapered to an acute point), indicate that strain UTEX 2540 has been misidentified. Heterotrichella gracillas is considered to be a member of the chlorophyll a and c-containing class Xanthophyceae (Chromista). However, HPLC analyses of photosynthetic pigments indicated the presence of chlorophylls a and b, ß-carotene, lutein and violaxanthin while ultrastructural data revealed the presence of starch stored inside the plastid. These data, as well as small subunit (18S rRNA) gene sequence analysis, indicate that this alga belongs in the Chlorophyta, not the Xanthophyceae (Chromista). Further DNA sequence analyses suggest that UTEX 2540 is most closely related to Geminella terricola Petersen and certain Microspora species that are currently classified in the Ulotrichales. However, unlike other Geminella species, UTEX 2540 exists as single cells or forms poorly organized (2-8 celled) ephemeral pseudofilaments. A conspicuous extracellular mucilaginous sheath characterizes other Geminella species but this feature is lacking in UTEX 2540. Furthermore, our analyses convincingly demonstrate that Geminella and at least some isolates of Microspora do not belong in the Ulotrichales. These results suggest that (1) the generic concept for Geminella must be broadened to include unicellular species that lack an apparent mucilaginous envelope, (2) Geminella does not belong in the Ulotrichales, and, instead, (3) its closest relatives among other green algae are almost certainly found within the Trebouxiophyceae

Vieraslajien havaitseminen Suomen merialueen seurannoissa

Julkaisussa kuvataan merialueemme keskeiset biologiset seurannat sekä niiden tuottama tieto Suomessa tavattujen meriympäristön vieraslajien levinneisyydestä ja runsaudesta. Kolmasosaa tunnetuista vieraslajeistamme ei ole tavattu seurannoissa koskaan, ja vain parin vieraslajin esiintymisestä saadaan nykyseurannoilla suhteellisen hyvä käsitys. Heikoimmin vieraslajiryhmistä tulivat esille kalat, matalien pohjien selkärangattomat ja kovien pohjien kiinni-istuvat pohjaeläimet. Kasviplankton- ja pohjaeläinseurannat ovat alueellisesti melko kattavia rannikollamme. Eläinplankton-, kala- ja makrofyyttiyhteisöjen (vesikasvit ja makrolevät) osalta seuranta on alueellisesti rajoittunut lähinnä eteläiselle merialueelle. Suuri osa vieraslajihavainnoista on peräisin seurantojen ulkopuolisista hankkeista ja kertaluontoisista tutkimuksista. Myös rannikon velvoitetarkkailut tuottavat havaintoja vieraslajeista. Vieraslajien nykyistä parempi havaitseminen vaatii osin pyyntimenetelmien kehittämistä ja osin näytteenottoverkon täydentämistä. Lisäksi viranomaisten ylläpitämien seurantojen tulosten tallentamisessa ja aineistojen saavutettavuudessa on parantamisen varaa. Tietoa vieraslajeista ja niiden tunnistamisesta tulisi toimittaa potentiaalisille vieraslajihavaintojen tuottajille, kuten kalastajille, konsulteille ja näytteiden määrittäjille, ja havaintojen ilmoittamismahdollisuuksia kehittää

New records and noteworthy data of plants, algae and fungi in SE Europe and adjacent regions, 14

This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: diatom algae Cyclostephanos invisitatus, Cyclotella meduanae, and Stephanodiscus lacustris, mycorrhizal fungi Alessioporus ichnusanus and Amanita mairei, saprotrophic fungi Diaporthe oncostoma, Stropharia albonitens and Pseudomassaria chondrospora, lichenised fungus Acrocordia subglobosa, stonewort Chara connivens, mosses Buxbaumia viridis, Tortella fasciculata and Tortula protobryoides, monocots Epipactis pontica Gymnadenia frivaldii, and Orchis italica and dicots Callitriche brutia, Callitriche platycarpa and Epilobium nutans are given within SE Europe and adjacent regions

Notes florístiques:

Abstract not availabl

Limnología de la laguna de Carralogroño (Álava)

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Ecología. Fecha de lectura: 23-06-201