Culture isolates of the genus Hypoglossum (Delesseriaceae, Rhodophyta) were obtained and their development and morphological structure over many years were followed in the laboratory. Molecular data (rbcL, large subunit ribosomal DNA, and cytochrome c oxidase subunit I) were obtained from these strains and evidence presented to recognize the new species: Hypoglossum sabahense from Sabah, Malaysia Because various aspects of morphology in culture specimens differ significantly from types based on field specimens we have to rely mainly on the molecular criteria in ascribing a new taxonomic name here. This also is complicated by the major lack of molecular phylogenetic evidence for Hypoglossum and other Delesseriaceae. The 'Germling Emergence Method' and 'serendipity' are proving valuable in discovering significant new taxa from laboratory cultures which otherwise might never be known.

SummaryPhylogenetic relationships and morphological characters are presented for a population of Nemalionopsis shawii Skuja collected from Nepal. Molecular data (sequences of rbcL and cox1) were generated and morphological characters were described in detail. The rbcL sequence analyses showed that specimens from Nepal are most similar to N. shawii from Indonesia and Japan and that these entities form a clade with high support (>95% bootstrap and 0.95 posterior probability). The cox1 barcode sequence, however, only had 90.9–91.9% identity with specimens of N. shawii from Hawaii. The rbcL sequence of the specimen from Nepal was positioned in a clade having sequence identity of 99.3–99.7% with three samples: N. shawii from Indonesia and two from Japan identified as N. tortuosa. The comparison of morphological characters of Nemalionopsis from Nepal allowed unequivocal identification with N. shawii. Identifications from previous studies using molecular data were mistaken since most reports of N. shawii are actually of N. tortuosa or vice‐versa. This confusion of names presumably occurred because most specimens previously sequenced were from culture collections or from ‘Chantransia’ stages. Small tufts of ‘Chantransia’ stage were observed growing epiphytically on gametophytes and on the basal system. Carpogonia and spermatangia were fully described in specimens from Nepal. Monosporangia were not observed, whereas carposporangia were unequivocally described for the first time in the genus. An unusual flat strap‐like basal system was observed, interpreted as an additional mode of maintenance in nature under unfavorable environmental conditions.

The Erythropeltidales are a ubiquitous group of red algae in the class Compsopogonophyceae. While their presence in the wild is often evident their taxonomy is frequently problematic. We approached the diversity of the group in northern Brittany, France by establishing unialgal cultures to find consistent characters and molecular methods to support the taxonomic conclusions. Erythrotrichia longistipitata sp. nov. is distinguished from other Erythrotrichia species by the elongate basal cell of erect filaments that is about 1.5-2.0 times longer than other intercalary cells. This species is molecularly distinct from all other genetic lineages of Erythrotrichia we have investigated. Erythrotrichia welwitschii is considered an obligate epiphyte of Ralfsia in the field, but in culture it grows well on glass. Monospores have bipolar germination, forming a lobed basal cell and an upper cell that becomes an upright filament. The basal cell in E. welwitschii becomes a multicellular disc from which secondary erect filaments can arise. Porphyrostromium boryanum has flat monostromatic upright blades and probable spermatia, carpogonia, and syngamy were observed. The complete sexual life history was not observed. Porphyrostromium ciliare with uniseriate and terete multiseriate upright shoots also produced probable spermatia and carpogonia but again the complete sexual life history was not observed. Observations of sex in the Erythropeltidales have never been completely resolved with the site of meiosis and the ploidy of various stages never fully explained.

Collections of marine and freshwater algae were made on Efate. Vanuatu Oil 14-16 June 2005. New records and cultures were obtained of the red algae Actinotrichia fragilis, Acrochaetium corymbiferum, Bostrychia moritziana, B. radicans, B. simpliciuscula, B. tenella, Caloglossa vieillardii, C. ogasawaraensis, Chroodactylon ornatum, Colaconema sp., Compsopogon sp., Murrayella periclados, Neosiphonia howei, Pulvinaster venetus, Stylonema alsidii, Thorea sp., the green algae Boodleopsis carolinensis and Derbesia tenuissima prox. and the cryptomonad Hemiselmis sp.

Les genes codant pour l'ARN ribosomique 18S de deux agents pathogenes d'algues brunes, Eurychasma dicksonii et Chytridium polysiphoniae, ont ete sequences afin de clarifier leur position phylogenetique. La sequence d'E. dicksonii se situe toujours a la base des Peronosporomycetes (Oomycetes) avec des valeurs de bootstrap elevees. Cependant elle est clairement separee de celles des autres Oomycetes terrestres ou d'eau douce. Le groupe le plus proche est un clade contenant uniquement des sequences environnementales provenant de sediments marins et de plancton oceanique. Les especes du genre Chytridium, groupees avec plusieurs autres genres (entre autres, Obelidium et Phlyctorhiza), forment un clade qui est voisin des organismes rattaches aux genres Monoblepharis, Rhizophydium, Lacustromyces, Nowakowskiella, Neocallimastix et Spizellomyces, a l'interieur des Chytridiomycetes, une des lignees principales des Eumycetes. La sequence de Chytridium polysiphoniae au contraire, forme avec des sequences environnementales aquatiques ou terrestres, un nouveau clade parmi les Chytridiomycetes, indiquant que la position systematique de cette espece devra etre revue. C. polysiphoniae contient de la chitine dans ses parois tandis que E. dicksonii contient de la cellulose, une composition parietale en accord avec leurs positions phylogenetiques respectives. Ces resultats suggerent qu'Eurychasma et Chytridium pourraient devenir des organismes modeles interessants, etant les seuls representants cultivables et morphologiquement connus d'une biodiversite aquatique tres mal connue ; ceci met en evidence la necessite d'inclure des representants marins dans les etudes phylogenetiques des Oomycetes et des Chytridiomycetes.

SUMMARY Olpidiopsis sp. (Oomycota) was cultured with its original host Bostrychia moritziana (Sonder ex Kützing) J. Agardh from Madagascar. Bean‐shaped zoospores with two heterokont flagella attached to the host cell wall surface and in 2 days host cells began collapsing and one or more syncytia developed in each infected cell. Zoospores were cleaved and an exit tube with a small plug was formed. Complete development and zoospore discharge occurred in 3 days. Infection occurred in cells of polysiphonous branches, monosiphonous branches, rhizoids and reproductive stichidia. Dead cells of plants treated with microwave were not infected. Susceptibility was variable in other Bostrychia species from different countries. Bostrychia moritziana (Sonder ex Kützing) J. Agardh, and Bostrychia radicans (Montagne) Montagne from Madagascar were susceptible but one Bostrychia tenella (J. V. Lamouroux) J. Agardh isolate from Madagascar was susceptible and two were not. B. radicosa (Itono) J. A. West, G. C. Zuccarello et M. Hommersand isolates from Madagascar, Thailand, Australia and New Caledonia were susceptible but an isolate from Malaysia was not. B. radicans isolates from Mexico and Brazil were non‐susceptible as were Bostrychia flagellifera Post, Bostrychia harveyi Montagne, Bostrychia montagnei Harvey, Bostrychia simpliciuscula Harvey ex J. Agardh, Bostrychia tenuissima R. J. King et Puttock, Stictosiphonia intricata(Bory de Saint‐Vincent) P. C. Silva, Stictosiphonia kelanensis (Grunow) R. J. King et Puttock and Stictosiphonia tangatensis (Post) R. J. King et Puttock, Lophosiphonia sp., Neosiphonia sp. and Polysiphonia spp. isolates were also non‐susceptible. Many non‐susceptible strains showed initial cell‐collapse followed by rapid wound‐repair cell formation without syncytia or sporangia developing. Caloglossa leprieurii (Montagne) G. Martens from Madagascar showed cell‐collapse and wound‐repair in periaxial cells, but wing cells died and became purple without wound‐repair. Caloglossa ogasawaraensis Okamura and Caloglossa postiae M. Kamiya et R. J. King had no symptoms of infection. Dasysiphonia chejuensis I. K. Lee et J. A. West was not infected. Surprisingly, the conchocelis phase but not the blade phase of Porphyra pulchella J. A.West, G. C. Zuccarello and Porphyra suborbiculata Kjellman was infected. The conchocelis of Porphyra tenera Kjellman and Porphyra linearis Greville were infected but no blade stages were tested. Porphyra miniata (C. Agardh) C. Agardh and Porphyra dentata Kjellman conchocelis were not infected. Bangia atropurpurea (Roth) C. Agardh gametophyte filaments were not infected. Other red, brown and green algae were not infected. Time lapse videomicroscopy of development and spore release was done.

The amino acid sequence of the signal transducer PII (GlnB) of the oceanic photosynthetic prokaryote Prochlorococcus marinus strain PCC 9511 displays a typical cyanobacterial signature and is phylogenetically related to all known cyanobacterial glnB genes, but forms a distinct subclade with two other marine cyanobacteria. PII of P. marinus was not phosphorylated under the conditions tested, despite its highly conserved primary amino acid sequence, including the seryl residue at position 49, the site for the phosphorylation of the protein in the cyanobacterium Synechococcus PCC 7942. Moreover, P. marinus lacks nitrate and nitrite reductase activities and does not take up nitrate and nitrite. This strain, however, expresses a low- and a high-affinity transport system for inorganic carbon (Ci; K m,app 240 and 4 μM, respectively), a result consistent with the unphosphorylated form of PII acting as a sensor for the control of Ci acquisition, as proposed for the cyanobacterium Synechocystis PCC 6803. The present data are discussed in relation to the genetic information provided by the P. marinus MED4 genome sequence.

The proteobacterial genus Helicobacter is composed of gastric species, all of them urease-positive, and enteric species (gastrointestinal, intestinal, hepatic, biliary), some of them urease-positive, others not. Here, we point out that the gastric species are divided in at least two phylogenetic groups, one is homogeneous, clearly separated from the enteric species, and another is forming a tight cluster within the enteric species. This feature is apparent in the phylogeny of the genus as inferred from both the 16S rRNA gene and the alpha-subunit of the urease. Our observation shows that the ability to colonize the gastric mucosa appeared more than once in the history of the genus, and suggests that acquiring this ability may be a relatively simple and punctual process, involving a limited number of genes. Such a process may be the lateral transfer acquisition of a functional copy of the gene ureI which encodes a urea channel activated at acidic pH that is essential for gastric colonization by Helicobacter pylori.

This review presents an account of the current knowledge concerning the endosymbiotic origin of plastids and mitochondria. The importance of algae as providing a large reservoir of diversified evolutionary models is emphasized. Several reviews describing the plastidial and mitochondrial genome organization and gene content have been published recently. Therefore we provide a survey of the different approaches that are used to investigate the evolution of organellar genomes since the endosymbiotic events. The importance of integrating population genetics concepts to understand better the global evolution of the cytoplasmically inherited organelles is especially emphasized.

A new algal class, the Bolidophyceae (Heterokonta), is described from one genus, Bolidomonas, gen. nov., and two species, Bolidomonas pacifica, sp. nov and Bolidomonas mediterranea, sp. nov., isolated from the equatorial Pacific Ocean and the Mediterranean Sea, respectively. Both species are approximately 1.2 μm in diameter and have two unequal flagella; the longer flagellum bears tubular hairs, whereas the shorter is smooth. The flagellar basal apparatus is restricted to two basal bodies, and there is no transitional helix. Cells are naked, devoid of walls or siliceous structures. The internal cellular organization is simple with a single plastid containing a ring genophore and a girdle lamella, one mitochondrion with tubular cristae, and one Golgi apparatus close to the basal bodies. The Mediterranean and the Pacific species differ in the insertion angle between their flagella and their pattern of swimming, these differences possibly being linked to each other. Analyses of the SSU rDNA gene place the two strains as a sister group to the diatoms. Moreover, pigment analyses confirm this position, as fucoxanthin is found as the major carotenoid in both lineages. These data strongly suggest that the ancestral heterokont that gave rise to the diatom lineage was probably a biflagellated unicell.

We recently reported (Gueneau et al ., 1998) the existence of a GC-rich region downstream of the trnR gene which was conserved in the plastidial genome of three algae: Thalassiosira weissflogii , Odontella sinensis (Bacillariophyceae) and Porphyra purpurea (Rhodophyceae). We identified this GC-rich region as a possible vestigial ORF and noted additional high similarity to an open reading frame (ORF) in a plastid from a fourth alga, Pavlova lutherii (Haptophyceae); sequence data from P. lutherii did not extend to the TΨC tRNA arm. We now report that this region instead encodes a recently recognized type of RNA known as tmRNA (Fig. 1 A ).

TAXONVolume 48, Issue 1 p. 139-140 Proposal to Conserve or Reject (1382) Proposal to conserve the name Pylaiella Bory (Phaeophyceae) with a conserved spelling Paul C. Silva, Paul C. Silva University Herbarium, University of California, Berkeley, CA, 94720-2465 U.S.A.Search for more papers by this authorDenis Lamy, Denis Lamy Muséum National d'Histoire Naturelle, Laboratoire de Cryptogamie, 12 rue Buffon, F-75005 Paris, FranceSearch for more papers by this authorSusan Loiseaux-de Goër, Susan Loiseaux-de Goër Station Biologique de Roscoff (C.N.R.S. UPR 9042, Université Pierre-et-Marie Curie), B.P. 74, F-29682 Roscoff Cedex, FranceSearch for more papers by this authorBruno de Reviers, Bruno de Reviers Muséum National d'Histoire Naturelle, Laboratoire de Cryptogamie, 12 rue Buffon, F-75005 Paris, FranceSearch for more papers by this author Paul C. Silva, Paul C. Silva University Herbarium, University of California, Berkeley, CA, 94720-2465 U.S.A.Search for more papers by this authorDenis Lamy, Denis Lamy Muséum National d'Histoire Naturelle, Laboratoire de Cryptogamie, 12 rue Buffon, F-75005 Paris, FranceSearch for more papers by this authorSusan Loiseaux-de Goër, Susan Loiseaux-de Goër Station Biologique de Roscoff (C.N.R.S. UPR 9042, Université Pierre-et-Marie Curie), B.P. 74, F-29682 Roscoff Cedex, FranceSearch for more papers by this authorBruno de Reviers, Bruno de Reviers Muséum National d'Histoire Naturelle, Laboratoire de Cryptogamie, 12 rue Buffon, F-75005 Paris, FranceSearch for more papers by this author First published: 01 February 1999 https://doi.org/10.2307/1224632Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume48, Issue1February 1999Pages 139-140 RelatedInformation

DNA sequence, copy number, expression and phylogenetic relevance of the psbA gene from the abundant marine prokaryote P. marinus CCMP 1375 was analyzed. The 7 amino acids near the C-terminus missing in higher plant and in Prochlorothrix hollandica D1 proteins are present in the derived amino acid sequence. P. marinus contains only a single psbA gene. Thus, this organism lacks the ability to adapt its photosystem II by replacement of one type of D1 by another, as several cyanobacteria do. Phylogenetic trees suggested the D1-1 iso-form from Synechococcus PCC 7942 as the next related D1 protein and place P. marinus separately from Prochlorothrix hollandica among the cyanobacteria.

Recent phylogenetic studies suggest that plastid ribosomal RNA genes from Pylaiella littoralis have a cyanobacterial origin, whereas their Rubisco genes are related to the homologous alpha- and beta- purple eubacterial genes. We have constructed a phylogenetic tree based upon the atpB and atpE sequences, including the same range of taxa (chlorophytes, chromophytes, cyanobacteria, alpha- and gamma-purple eubacteria) and using the same methods as previously described for rbcL genes. This phylogenetic tree clearly shows that the atpB and atpE genes of this brown alga are more closely related to their cyanobacterial homologues than to those of alpha- or gamma-purple eubacteria. Different hypotheses that could explain the apparently composite origin of red-chromophyte plastomes are discussed.

The plastid genome of the brown alga Pylaiella littoralis (L.) Kjellm. is composed of two different circular DNA molecules: the largest carries two rrn operons, and the smallest, only one copy of both 16S and 23S rDNAs. 16S rDNA copies located on both molecules have been cloned and their nucleotide sequences determined: they are 65% homologous to one another. The expression of these genes was assayed by hybridizing in vivo labelled P. littoralis rRNAs to both clones, and specific oligonucleotides to total RNA from P. littoralis. Results indicate that the 16S rDNA copy located on the small molecule is a pseudogene. Comparisons of the functional gene with other 16S rRNA genes shows that chloroplasts from green plants emerged earlier from the cyanobacterial lineage than Euglena gracilis and Pylaiella littoralis plastids.

The DNA segment situated between the 16S and 23S rRNA genes belonging to the plastid genome of the brown alga Pylaiella littoralis (L.) Kjellm. has been sequenced. This small region (322 bp) contains two unsplit tRNA genes separated by 3 bp. A comparison with similar regions from different plants shows that this region has evolved in two different ways according to the place of plants in evolution. In the "primitive" group, this region is reduced in size when compared to prokaryotes. In the other groups, it is considerably enlarged by insertion of repetitive sequences, open reading frames and introns.