ANALYSIS OF ANCIENT DNA FROM FOSSIL CORALLINES (CORALLINALES,RHODOPHYTA)1

The field of molecular paleontology has recently made significant contributions to anthropology and biology. Hundreds of ancient DNA studies have been published, but none has targeted fossil coralline algae. Using regions of the SSU gene, we analyzed rDNA from fossil coralline algae of varying ages and states of preservation from Spain, Papua New Guinea (PNG), and the Great Barrier Reef (GBR). Specimens from PNG, GBR, and some localities from Spain did not contain endogenous ancient DNA. Reproducible sequence data were obtained from specimens ～550 years old from near Cadiz, Spain, and from rocky‐shore deposits in Carboneras, Almeria Province of Spain (～78,000 years before present [YBP]). Based on BLAST searches and a phylogenetic analysis of sequences, an undescribed coralline alga belonging to the Melobesioideae was discovered in the Carboneras material as well as the following coralline genera: Jania, Lithophyllum, Lithothamnion, Mesophyllum, and Phymatolithon. DNA from fleshy brown and red macroalgae was also discovered in the specimens from Carboneras. The coralline algae identified using molecular techniques were in agreement with those based on morphological methods. The identified taxa are common in the present‐day southeastern Spain littoral zone. Amino acid racemization, concentration ratios, and specific concentrations failed to show a correlation between biomolecular preservation and PCR amplification success. Results suggest that molecular investigations on fossil algae, although limited by technical difficulties, are feasible. Validity of our results was established using authentication criteria and a self‐critical approach to compliance.     

THE EVOLUTION OF PARASITISM IN THE RED ALGAE: MOLECULAR COMPARISONS OF ADELPHOPARASITES AND THEIR HOSTS1

In several groups of parasites including insect, flowering plant, fungal, and red algal parasites, morphological similarities of the parasites and their specific hosts have led to hypotheses that these parasites evolved from their hosts. But these conclusions have been criticized because the morphological features shared by parasite and host may be the result of convergent evolution. In this study, we examine the hypothesis, originally put forth by Setchell, that adelphoparasitic red algae, that is, parasitic red algae that are morphologically very similar to their hosts, evolved from their specific red algal hosts. Rather than comparing morphological features of parasites and hosts, small-subunit 18S nuclear ribosomal DNA and the internal transcribed spacer regions (ITSs) of the nuclear ribosomal repeat are compared for five parasites, their hosts, and related nonhosts from four red algal orders. These comparisons reveal that each of these adelphoparasites has evolved either directly from the host on which it is currently found, or it evolved from some other taxon that is closely related to the modern host. The parasites Gardneriella tuberifera, Rhodymeniocolax botryoides, and probably Gracilariophila oryzoides evolved from their respective hosts Sarcodiotheca gaudichaudii, Rhodymenia pacifica, and Gracilariopsis lemaneiformis, respectively. The parasite Faucheocolax attenuata evolved from either Fauchea laciniata or Fauchea fryeana and subsequently radiated onto the other host species. Presently this parasite is found on both hosts. Lastly, some parasitic genera such as Plocamiocolax are polyphyletic in their origins. A species of Plocamiocolax from an Antarctic Plocamium cartilagineum appears to have evolved from its host whereas the common Plocamiocolax pulvinata that occurs along the west coast of North America likely evolved from Plocamium violaceum and radiated secondarily onto its present day host, Plocamium cartilagineum.     

A COMPOSITE RATING OF ALGAE TOLERATING ORGANIC POLLUTION2

From information on pollution-tolerant algae compiled from reports from 165 authors, the genera and species most often referred to as significant fall into a relatively stable series. Diatoms, pigmented flagellates, green, and blue-green algae are all well represented among the pollution-tolerant genera and species. The top 8 genera are Euglena, Oscillatoria, Chlamydomonas, Scenedesmus, Chlorella, Nitzschia, Navicula, and Stigeoclonium, and the top 5 species, Euglena viridis, Nitzschia palea, Oscillatoria limosa, Scenedesmus quadricauda, and Oscillatoria tennis. In some genera, e.g., Euglena, a single species is far more significant than all others as a pollution-tolerant form. In other genera, e.g., Oscillatoria, only a slight difference distinguishes the pollution tolerance of 2 or more species. Algal genus and species pollution indices arc presented for use in rating water samples with high organic pollution.     

PHYLOGENY OF THE CONJUGATING GREEN ALGAE BASED ON CHLOROPLAST AND MITOCHONDRIAL NUCLEOTIDE SEQUENCE DATA1

The conjugating green algae represent a lineage of charophyte green algae known for their structural diversity and unusual mode of sexual reproduction, conjugation. These algae are ubiquitous in freshwater environments, where they are often important primary producers, but few studies have investigated evolutionary relationships in a molecular systematic context. A 109‐taxon data set consisting of three gene fragments (two from the chloroplast and one from the mitochondrial genome) was used to estimate the phylogeny of the genera of the conjugating green algae. Maximum likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) were used to estimate relationships from the 4,047 alignable nucleotides. This study confirmed the polyphyly of the Zygnemataceae and Mesotaeniaceae with respect to one another. The Peniaceae were determined to be paraphyletic, and two genera traditionally classified among the Zygnematales appear to belong to the lineage that gave rise to the Desmidiales. Six genera, Euastrum, Cosmarium, Cylindrocystis, Mesotaenium, Spondylosium, and Staurodesmus, were polyphyletic in this analysis. These findings have important implications for the evolution of structural characteristics in the group and will require some taxonomic changes. More work will be required to delineate lineages of Zygnematales in particular and to identify structural synapomorphies for some of the newly identified clades.     

The effect of pH upon the photosynthesis of littoral marine algae

Summary The photosynthetic rates of a number of littoral marine algae were determined over a pH range from 8.1 to 10.3, employing the Winkler technique to measure evolved oxygen. In a large number of red, brown and green algae, the rate fell to a low value, or to complete inhibition, at pH 9.5 and higher. This indicates, in conformity with general permeability theory, that the HCO₃ ^}-ion cannot readily penetrate the cells, and is hence not available for photosynthesis.However, in two genera of coralline red algae (Bossea andCorallina) photosynthesis persists up to pH 10 or higher (though at a considerably reduced rate). This can be interpreted as due to utilization of the HCO₃ ^}-ion (though probably not the CO₃=ion). But several other non-coralline red algae (Centroceras, Botryocladia andGastroclonium), as well as the brown algaPelvetia (and possiblyFucus), and the green algaeUlva andEnteromorpha display this same ability.Thus the utilization of HCO₃ ^}-ion cannot alone be ascribed as the cause of calcium carbonate deposition, since several other non-calcareous algae have this same power. The utilization of HCO₃ ^}-at least permits calcification, however. The question might be reversed, to ask whyUlva, Enteromorpha. Pelvetia and several red algae are not calcified. Some cell wall property may be involved.     

MORPHOLOGICAL STUDIES IN A NEW SPECIES OF ACROSYMPHYTON (RHODOPHYCEAE)

Abbott , Isabella A. (Hopkins Marine Sta. of Stanford U., Pacific Grove, Calif.) Morphological studies in a new species of Acrosymphyton (Rhodophyceae). Amer. Jour. Bot. 49(8): 845–849. Illus. 1962.—Acrosymphyton taylori sp. nov. (Dumontiaceae, Cryptonemiales, Rhodophyceae) is shown to have a sexual cycle essentially similar to that of the 2 other species in the genus, but differs in some details of the sexual structures and the vegetative structure. Acrosymphyton taylori, from the Hawaiian Islands, is the only member of the genus from the Pacific. Acrosymphyton is only one of several genera of red algae possessing soft, gelatinous, uniaxial thalli. A study of specimens from various herbaria showed that specimens of Dudresnaya and Calosiphonia have been confused with Acrosymphyton.     

EOCENE ALGAE AND PLANT HAIRS FROM THE GREEN RIVER FORMATION OF WYOMING

Four new species of algae and two kinds of fossil plant hairs are described from a rich oil shale bed of the mid-Eocene Green River Formation of Wyoming. Two of the algae belong to the Cyanophyceae and two to the Chlorophyceae. On the basis of their morphology alone, they are assigned to four new species among four genera, as follows: Symploca hedraia, sp. n.; Stigonema anchistina, sp. n.; Schizochlamys haywellensis, sp. n.; and Spirogyra wyomingia, sp. n. One kind of fossil plant hair is similar to those observed in organic sediments of an existing lake and identified with trichomes on the under surface of live oak leaves (Quercus virginiana). Assignment of the fossil trichomes to a taxon is not warranted at present.     

Phylogeny of Gracilariaceae (Rhodophyta): evidence from plastid and mitochondrial nucleotide sequences

Gracilariaceae are mostly pantropical red algae and include ~230 species in seven genera. Infrafamilial classification of the group has long been based on reproductive characters, but previous phylogenies have shown that traditionally circumscribed groups are not monophyletic. We performed phylogenetic analyses using two plastid (universal plastid amplicon and rbcL) and one mitochondrial (cox1) loci from a greatly expanded number of taxa to better assess generic relationships and understand patterns of character distributions. Our analyses produce the most well‐supported phylogeny of the family to date, and indicate that key characteristics of spermatangia and cystocarp type do not delineate genera as commonly suggested. Our results further indicate that Hydropuntia is not monophyletic. Given their morphological overlap with closely related members of Gracilaria, we propose that Hydropuntia be synonymized with the former. Our results additionally expand the known ranges of several Gracilariaceae species to include Brazil. Lastly, we demonstrate that the recently described Gracilaria yoneshigueana should be synonymized as G. domingensis based on morphological and molecular characters. These results demonstrate the utility of DNA barcoding for understanding poorly known and fragmentary materials of cryptic red algae.     

Cyanobacteria of Rocks and Soils of the Orinoco Lowlands and the Guayana Uplands,Venezuela

The occurrence of 23 cyanobacterial species, belonging to 9 different genera and 5 cyanobacterial lichen species of 5 different genera on exposed, open rock surfaces of inselbergs and on soil in savannas of the Orinoco lowlands and the Guayana uplands is described. Their distribution patterns and frequency within the different habitats are given. The filamentous procaryotic blue-green algae/cyanobacteria Stigonema ocellatum and Scytonema crassum, together with the unicellular cyanobacterium Gloeocapsa sanguinea were the most frequent species on rocks, whereas the filamentous cyanobacterium, Schizothrix telephoroides, dominated in cyanobacterial mats on the savanna soil. All species showed intensively coloured sheaths, either brown or yellow in the case of Stigonema ocellatum and Scytonema crassum, or red in Gloeocapsa sanguinea and Schizothrix telephoroides. In addition, a number of cyanobacterial lichens occurred.     

MOLECULAR PHYLOGENY AND REVISION OF THE GENUS NETRIUM (ZYGNEMATOPHYCEAE,STREPTOPHYTA): NUCLEOTAENIUM GEN. NOV.1

Nuclear‐encoded SSU rDNA, chloroplast LSU rDNA, and rbcL genes were sequenced from 53 strains of conjugating green algae (Zygnematophyceae, Streptophyta) and used to analyze phylogenetic relationships in the traditional order Zygnematales. Analyses of a concatenated data set (5,220 nt) established 12 well‐supported clades in the order; seven of these constituted a superclade, termed “Zygnemataceae.” Together with genera (Zygnema, Mougeotia) traditionally placed in the family Zygnemataceae, the “Zygnemataceae” also included representatives of the genera Cylindrocystis and Mesotaenium, traditionally placed in the family Mesotaeniaceae. A synapomorphic amino acid replacement (codon 192, cysteine replaced by valine) in the LSU of RUBISCO characterized this superclade. The traditional genera Netrium, Cylindrocystis, and Mesotaenium were shown to be para‐ or polyphyletic, highlighting the inadequacy of phenotypic traits used to define these genera. Species of the traditional genus Netrium were resolved as three well‐supported clades each distinct in the number of chloroplasts per cell, their surface morphology (structure and arrangement of lamellae) and the position of the nucleus or nuclear behavior during cell division. Based on molecular phylogenetic analyses and synapomorphic phenotypic traits, the genus Netrium has been revised, and a new genus, Nucleotaenium gen. nov., was established. The genus Planotaenium, also formerly a part of Netrium, was identified as the sister group of the derived Roya/Desmidiales clade and thus occupies a key position in the evolutionary radiation leading to the most species‐rich group of streptophyte green algae.     

LITOSTROMA,A NEW GENUS OF PROBLEMATICAL ALGAE FROM THE PENNSYLVANIAN OF OKLAHOMA

Mamay , Sergius H. (U. S. Geological Survey, Washington, D. C.) Litostroma, a new genus of problematical algae from the Pennsylvanian of Oklahoma. Amer. Jour. Bot. 46(4): 283–292. Illus. 1959.—Litostroma oklahomense, gen. et sp. nov. is described on the basis of fossil plant material found in a Pennsylvanian marine limestone from the vicinity of McAlester, Oklahoma. Litostroma is a simple plant consisting of a small, irregularly shaped thallus 1 cell thick. Some thalli have small perforations and filament-like marginal outgrowths. The reproductive organs are not known. A marine fauna is intimately associated with Litostroma, and includes epiphytic Foraminifera preserved in actual growth positions on surfaces of the plants. The evidence indicates a marine habitat for Litostroma and, accordingly, algal affinity. Without information bearing on its reproductive organs or pigmentation, however, Litostroma cannot with assurance be assigned to any known group of algae. It possibly represents a group of green, brown, or even red algae.     

Putting incertae sedis taxa in their place: a proposal for ten new families and three new genera in Sphaeropleales (Chlorophyceae,Chlorophyta)

Best known for aquatic colonial algae such as Hydrodictyon, Pediastrum, or Scenedesmus, the order Sphaeropleales also contains numerous coccoid taxa from aquatic and terrestrial habitats. Recent findings indicate that coccoid lineages in this order are very diverse genetically and may be the prevalent form, although their diversity is often hidden morphologically. This study characterizes coccoid algae recently discovered from desert soil crusts that share morphological and ecological features with the genera Bracteacoccus, Pseudomuriella, and Chromochloris. Analyses of a multi‐gene data set that includes members from all sphaeroplealean families are used to examine the monophyly of these morphologically similar taxa, which are shown instead to be phylogenetically distinct and very divergent. We propose new generic names for these lineages: Bracteamorpha, Rotundella, and Tumidella. In addition, we propose an updated family‐level taxonomy within Sphaeropleales that includes ten new families of coccoid algae to accommodate the newly presented genera and many incertae sedis taxa in the order: Bracteamorphaceae, Chromochloridaceae, Dictyococcaceae, Dictyochloridaceae, Mychonastaceae, Pseudomuriellaceae, Rotundellaceae, Schizochlamydaceae, Schroederiaceae, and Tumidellaceae.     

ELECTROPHORETIC AND IMMUNOLOGICAL ANALYSES OF SEVEN CHLOROSARCINACEAN ALGAE1

Proteins from 7 species of chlorosarcinacean algae representing 4 genera were studied with starch and disc gel electrophoresis and immunology to determine biochemical relationships. Migration patterns of enzymes and serological reactions indicated that 4 species of Chlorosarcinopsis were closely related, whereas Friedmannia israeliensis, Fasciculochloris boldii, and Chlorosarcina longispinosa were more diverse. Malate dehydrogenase, glutamate dehydrogenase, nonspecific alpha esterases, and peroxidase (using pyrogallol as the hydrogen donor) were present in all 7 species. No peroxidase activity occurred with benzidine. Leucine aminopeptidase was obvious in only 2 species. A single distinct band of general protein in F. israeliensis and C. longispinosa suggested the presence of homogenous reserve protein. The 7 species exhibited serological affinity to 4 isolates of Protosiphon representing diverse morphology within the genus. The data are discussed relative to current knowledge of comparative morphology of chlorosarcinacean algae.     

PHYLOGENY OF GRACILARIA LEMANEIFORMIS (RHODOPHYTA) BASED ON SEQUENCE ANALYSIS OF ITS SMALL SUBUNIT RIBOSOMAL RNA CODING REGION1

The small subunit ribosomal RNA (rRNA) sequence of Gracilaria lemaneiformis Bory Weber-van Bosse was inferred from analysis of rRNA coding regions that were amplified by the polymerase chain reaction method. Comparison of the G. lemaneiformis small subunit rRNA to homologous genes of diverse eukaryotes demonstrated that the red algal divergence was nearly simultaneous with the separation of plants, fungi, animals and many other protist lineages. This result conflicts with those of 5S rRNA sequence and plastid based phytogenies which suggest that red algae represent an early divergence in the eukaryotic line of descent. Further, algae appear to be of polyphyletic origin and red algae are unrelated to higher fungi.     

ULTRASTRUCTURE OF CELL DIVISION AND REPRODUCTIVE DIFFERENTIATION OF MALE PLANTS IN THE FLORIDEOPHYCEAE (RHODOPHYTA): CELL DIVISION IN POLYSIPHONIA1

Cell division in the marine red algae Polysiphonia harveyi Bailey and P. denudata (Dillwyn) Kutzing was studied with the electron microscope. Cells comprising the compact spermatangial branches of male plants were used exclusively because of their small size, large numbers and the ease with which the division planes can be predetermined. Some features characterizing mitosis in Polysiphonia confirm earlier electron microscope observations in Membranoptera, the only other florideophycean algae in which mitosis has been studied in detail. Common to both genera are a closed, fenestrated spindle, perinuclear endoplasmic reticulum, a typical metaphase plate arrangement of chromosomes, conspicuous, layered kinetochores, chromosomal and non-chromosomal microtubules, and nucleus associated organelles (NAOs) known as polar rings (PRs) located singly in large ribosome-free zones of exclusion at division poles in late prophase. However, other features, unreported in Membranoptera, were observed consistently in Polysiphonia. These include the presence of PR pairs in interphase-early prophase cells, the attachment of PRs to the nuclear envelope during all mitotic stages, the migration of a single PR to establish the division axis, a prominent, nuclear envelope protrusion (NEP) at both division poles at late prophase, the prometaphase splitting of PRs into proximal and distal portions, and the reformation of post-mitotic nuclei by the separation of an elongated interzonal nuclear midpiece at telophase. During cytokinesis, cleavage furrows impinge upon a central vacuolar region located between the two nuclei and eventually pit connections are formed in a manner basically similar to that reported for other red algae. Diagrammatic sequences of proposed PR behavior during mitosis are presented which can account for events known to occur during cell division in Polysiphonia. Mitosis is compared with that reported in several other lower plants and it is suggested that features of cell division are useful criteria to aid in the assessment of phylogenetic relationships of red algae.     

Amino acid composition, protein content and calculation of nitrogen-to-protein conversion factors for 19 tropical seaweeds

The use of nitrogen‐to‐protein conversion factors (N‐Prot factors) is the most practical way of determining protein content. The accuracy of protein determination by this method depends on the establishment of N‐Prot factors specific to individual species. Experimental data are needed to allow the use of this methodology with seaweeds. The present study was designed to characterize the amino acid composition and to establish specific N‐Prot factors for six green, four brown and nine red marine algae. Mean values for individual amino acids tended to be similar among the three groups, but some differences were found. Green algae tended to show lower percentages of both aspartic acid and glutamic acid than the other two groups of algae. The percentages of both lysine and arginine were higher in red algae, while brown algae tended to show more methionine than green and red algae. The actual protein content of the species, based on the sum of amino acid residues, varied from 10.8% (Chnoospora minima, brown algae) to 23.1% (Aglaothamnion uru‐guayense, red algae) of the dry weight. Nitrogen‐to‐protein conversion factors were established for the species studied, based on the ratio of amino acid residues to total nitrogen, with values ranging from 3.75 (Cryptonemia seminervis, red algae) to 5.72 (Padina gymnospora, brown algae). The relative importance of non‐protein nitrogen is greater in red algae, and consequently lower N‐Prot factors were calculated for these species (average value 4.59). Conversely, protein nitrogen content in both green and brown algae tends to be higher, and average N‐Prot factors were 5.13 and 5.38, respectively. An overall average N‐Prot factor for all species studied of 4.92 ± 0.59 (n = 57) was established. This study confirms that the use of the traditional factor 6.25 is unsuitable for seaweeds, and the use of the N‐Prot factors proposed here is recommended.