Studies of marine algae in the lesser-known families of the Gigartinales (Rhodophyta). III. The Mychodeaceae and Mychodeophyllaceae

1978 ◽  
Vol 26 (4) ◽  
pp. 515 ◽  
Author(s):  
GT Kraft
Keyword(s):  
Marine Algae ◽  
Adjacent Cell ◽  
Distinctive Pattern ◽  
Supporting Cells ◽  
New Family ◽  
Red Algal ◽  
Single Genus ◽  
Fusion Cell ◽  
Fertile Region ◽  
Axial Development

The endemic Australian red algal families Mychodeaceae Kylin and Mychodeophyllaceae fam. nov. are described and characterized in vegetative and reproductive detail. The Mychodeaceae is composed of the single genus Mychodea and 11 species which are distinguished on habit features and vegetative differences. Plants are uniaxial with a distinctive pattern of axial development, monoecious, zonately tetrasporangiate, procarpic and polycarpogonial. Supporting cells of carpogonial branches function as auxiliary cells which remain unfused to adjacent cells after diploidization and emit numerous gonimoblast filaments towards the centre of the thallus. The gonimoblasts become secondarily pitconnected to gametophytic cells which they lie next to and eventually appear to break up into isolated groups of cells which both initiate additional carposporangial precursors and enlarge directly into carposporangia themselves. Carposporangial initials can form secondary pit-connections to any type of adjacent cell, which results in irregularly branched carposporangial clusters whose cells are frequently attached to sterile gametophytic cells within and around the periphery of the cystocarp. Mature cystocarps consist of a non-ostiolate pericarp and pockets of carposporangia isolated between persistent sterile cells throughout the fertile region. The genera Neurophyllis Zanardini and Ectoclinium J. Agardh are placed in synonymy with Mychodea, and all extra-Australian records of the group are discounted or questioned. A new family, the Mychodeophyllaceae, is created for Mychodeophyllum papillitectum gen. et sp. nov. from Western Australia. Mychodeophyllum shares spermatangial and tetrasporangial features with Mychodea, as well as sexual elements such as polycarpogonial procarps, lack of a fusion cell, and multiple, inwardly growing gonimoblast initials. Gonimoblast filaments develop quite differently from Mychodea, however, and carposporangia form radiating chains around the periphery of a central placenta composed of mixed and secondarily connected gonimoblast and gametophytic filaments. Plants of the genus are also apparently rnultiaxial. The Mychodeaceae and Mychodeophyllaceae appear to be highly specialized in vegetative and carposporophyte structure, and have given rise to no known higher lines of development. It is speculated that both families may represent offshoots from ancestors at a level of carposporophyte complexit) represented by present-day Rhabdoniaceae, Solieriaceae and Rhodophyllidaceae.

Studies of Marine algae in the lesser-known families of the Gigartinales (Rhodophyta). II. The Dicranemaceae

1977 ◽  
Vol 25 (2) ◽  
pp. 219 ◽  
Author(s):  
GT Kraft
Keyword(s):  
Marine Algae ◽  
Supporting Cell ◽  
Branch System ◽  
Auxiliary Cell ◽  
Cell Position ◽  
The Family ◽  
Red Algal ◽  
Carpogonial Branch ◽  
Advanced Stages ◽  
Fusion Cell

The red algal family Dicranemaceae (Gigartinales) has been studied with regard to its vegetative and reproductive morphology, The group is composed of two Dicranema species (D. revolutum (C. Ag.) J. Ag. and D. cincinnalis sp, nov.), Peltasta australis J. Ag., Reptataxis rhizophora (Lucas) gen. et comb. nov., and Tylotus obtusatus (Sond.) J . Ag. All except Reptataxis, from Lord Howe I., are endemic to southern Australia. The last three genera are newly added to the family, which is redefined to embrace their early gonimoblast similarities to Dicranema. The species are all multiaxial, zonately tetrasporangiate and monoecious. Dicranema, Peltasta and Reptataxis have broad, cellular cortexes and filamentous medullas, while Tylotus is pseudoparenchymatous throughout. Tetrasporangia are nemathecial in Dieranem, Reptataxis and Tylotus, but scattered in Peltasta. Spermatangia in Dicranema are formed in deeply buried catenate clusters, and are similarly derived but non-catenate in the other genera. The species are all monocarpogonial, and only Tylotus is procarpic. In none of the genera are sterile cells associated with carpogonial branches. In Tylotus the supporting cell of the carpogonial branch fuses with the presumably fertilized carpogonium and becomes the diploidized auxiliary cell. In Dicranema, Peltasta and Reptataxis, 2- or 3-celled carpogonial branches are directed to the thallus surface and presumably fertilized carpogonia fuse with an auxiliary cell not necessarily on the same cortical branch system as the supporting cell. Diploidized auxiliary cells in all four genera form small, irregular fusion cells and emit multiple, filamentous gonimoblasts. Gonimoblast growth is mostly thallus-inward in Dicranema, initially radial in Peltasta and Reptataxis, and lateral and outward in Tylotus and advanced stages of Peltasta and Reptataxis. In Dicranema, Peltasta and Reptataxis an extensive placenta of mixed and connected gonimoblast and vegetative cells forms between the fusion cell and the peripheral carpospore-producing layers. In Tylotus vegetative/gonimoblast cell connections occur mainly at the floor of the cystocarp. Carposporangia develop singly on elongate penultimate gonimoblasts in Dicranema and Tylotus, but form chains in Peltasta and Reptataxis. Cystocarps in all the genera are surrounded by thick ostiolate pericarps. The genera of the Dicranemaceae are distinct from one another on frond and holdfast habits, vegetative structure, carpogonial branch shape, auxiliary cell position, gonimoblast orientation, carposporangial size, and mature cystocarp location and cross section. None of the four genera seem obviously derived from or particularly closely related to any others outside the family, although both Peltasta and Reptataxis show some features susesting possible links to the Sarcodiaceae.

scholarly journals Scaffolding proteins guide the evolution of algal light harvesting antennas

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Harry W. Rathbone ◽  
Katharine A. Michie ◽  
Michael J. Landsberg ◽  
Beverley R. Green ◽  
Paul M. G. Curmi
Keyword(s):  
Hydrophobic Surface ◽  
Scaffolding Protein ◽  
Secondary Endosymbiosis ◽  
Scaffolding Proteins ◽  
Α Subunit ◽  
Binding Partner ◽  
Photosynthetic Organisms ◽  
New Family ◽  
Red Algal ◽  
Multiple Copies

AbstractPhotosynthetic organisms have developed diverse antennas composed of chromophorylated proteins to increase photon capture. Cryptophyte algae acquired their photosynthetic organelles (plastids) from a red alga by secondary endosymbiosis. Cryptophytes lost the primary red algal antenna, the red algal phycobilisome, replacing it with a unique antenna composed of αβ protomers, where the β subunit originates from the red algal phycobilisome. The origin of the cryptophyte antenna, particularly the unique α subunit, is unknown. Here we show that the cryptophyte antenna evolved from a complex between a red algal scaffolding protein and phycoerythrin β. Published cryo-EM maps for two red algal phycobilisomes contain clusters of unmodelled density homologous to the cryptophyte-αβ protomer. We modelled these densities, identifying a new family of scaffolding proteins related to red algal phycobilisome linker proteins that possess multiple copies of a cryptophyte-α-like domain. These domains bind to, and stabilise, a conserved hydrophobic surface on phycoerythrin β, which is the same binding site for its primary partner in the red algal phycobilisome, phycoerythrin α. We propose that after endosymbiosis these scaffolding proteins outcompeted the primary binding partner of phycoerythrin β, resulting in the demise of the red algal phycobilisome and emergence of the cryptophyte antenna.

The marine algae of Lord Howe Island (NSW) the family Solieriaceae (Gigartinales, Rhodophyta)

Brunonia ◽  
1984 ◽  
Vol 7 (2) ◽  
pp. 217 ◽  
Author(s):  
PW Gabrielson ◽  
GT Kraft
Keyword(s):  
New Species ◽  
Marine Algae ◽  
The Other ◽  
Lord Howe Island ◽  
The Family ◽  
Red Algal

The red algal family Solieriaceae is represented by the three genera Solieria, Meristotheca and Eucheuma at Lord Howe Island (31�33'S.,159�05'E.). Each genus is represented by two species, one of which is widespread geographically and the other newly described. The new species (Solieria anastomosa, Eucheuma deformans, Meristotheca procumbens) are characterized vegetatively and reproductively, as are the three previously described species [Solieria robusta (Greville) Kylin, Eucheuma serra (J. Agardh) J. Agardh, Meristotheca papulosa (Montagne) J. Agardh]. Mychodea halymenioides Zanardini, which is based on a Lord Howe specimen, is placed in synonymy with Meristotheca papulosa. Partly as a result of the Lord Howe study, the Solieriaceae is recircumscribed using a suite of characters that is taxonomically more useful than that currently delimiting the family.

New species of marine algae from California

1968 ◽  
Vol 46 (10) ◽  
pp. 1235-1251 ◽  
Author(s):  
George J. Hollenberg ◽  
Isabella A. Abbott
Keyword(s):  
New Species ◽  
New Taxa ◽  
Red Algae ◽  
Marine Algae ◽  
The Other ◽  
New Family ◽  
New Varieties ◽  
First Time

Eleven new taxa are described from California; two species, in addition, have new varieties added to them; and two species are given new circumscriptions to include a number of entities previously known under other names. New species are described in Percursaria (Chlorophyta), in Feldmannia (Phaeophyta), and in eight genera (Membranella, Porphyra, Rhododiscus, Peyssonelia, Prionitis, Blinksia, Besa and Rhodoglossum) of Rhodophyta. Two monotypic genera of Rhodophyta are described for the first time. One, Membranella nitens, is added to the Bangiales, and the other, Blinksia californica, is the type for a new family, the Blinksiaceae (Gigartinales). Half of the species of red algae are crustose non-corallinaceous species.

The genus Bornetia (Rhodophyta, Ceramiaceae) and its Southern Australian representatives, with dscription of Involucrana gen. Nov

1968 ◽  
Vol 16 (2) ◽  
pp. 197 ◽  
Author(s):  
RN Baldock ◽  
HBS Womersley
Keyword(s):  
Type Species ◽  
Marine Algae ◽  
New Genus ◽  
Lateral Branch ◽  
The Other ◽  
Terminal Branch ◽  
Additional Species ◽  
Australian Species ◽  
Fusion Cell

Two species of southern Australian marine algae have been previously placed in Bornetia. One, B. binderiana (Sonder) Zanardini, shows the generic features of the type species from Europe (B. secundiflora), and an additional species, B. tenuis, is also described for the genus. Study of the type and the above two Australian species shows that Bornetia is characterized by subdichotomous filaments of elongate cells, a 5-6(-8)-celled fertile axis developing procarps successively and also non-functional pseudocarpogonia, an involucre produced from the lower cells of the fertile axis, and a large stellate fusion cell; and by the production of tetrasporangia and spermatangial heads in condensed clusters in which the terminal branch cells curve around the cluster as an involucre. The other Australian species, B. ? Meredithiana J. Agardh, has procarps confined to the subterminal cell of a 3-celled fertile axis, and after fertilization sterile cells associated with the procarp produce an inner involucre around the carposporophyte, which has a massive fusion cell. Sessile polysporangia are borne in condensed lateral branch clusters. A new genus, Involucrana, is proposed for this species. Its relationships are probably with Sphondylothamnion, which also differs from other known Ceramiaceae in having a similar inner involucre.

The marine algae of British Columbia, northern Washington, and southeast Alaska: division Rhodophyta (red algae), class Rhodophyceae, order Gelidiales

1989 ◽  
Vol 67 (11) ◽  
pp. 3295-3314 ◽  
Author(s):  
Dawn E. Renfrew ◽  
Paul W. Gabrielson ◽  
Robert F. Scagel
Keyword(s):  
British Columbia ◽  
Marine Algae ◽  
Algal Flora ◽  
Historical Time ◽  
Southeast Alaska ◽  
Strait Of Georgia ◽  
Northeast Pacific ◽  
Red Algal ◽  
Marine Algal ◽  
First Time

The red algal order Gelidiales is represented in the benthic marine algal flora of British Columbia, northern Washington, and southeast Alaska by two genera, Gelidium Lamouroux and Pterocladia J. Agardh. Three species of Gelidium are present, G. coulteri Harvey, G. purpurascens Gardner, and G. vagum Okamura, and one species of Pterocladia, P. caloglossoides (Howe) Dawson. For each species we provide a description of its habit and life history, vegetative and reproductive morphology, and habitat and seasonality. Distributions and representative specimens examined are given. Keys are provided to genera and species where appropriate. Habits, and salient vegetative and reproductive features useful in identifying each species, are illustrated. Gelidium vagum is reported for the first time in the northeast Pacific and appears to have been introduced to the flora from Japan in recent historical time. Its distribution is limited to two islands in the Strait of Georgia. Gelidium purpurascens and Pterocladia caloglossoides are distributed throughout British Columbia and northern Washington, and their ranges are extended north to southeast Alaska. Earlier reports of G. amansii (Lamouroux) Lamouroux, G. crinale (Turner) Lamouroux, G. pusillum (Stackhouse) Le Jolis, G. robustum (Gardner) Hollenberg et Abbott, and G. sinicola Gardner from British Columbia and northern Washington are shown to have been based upon misidentifications of other taxa, and these species are excluded from the flora.

scholarly journals Resurrection of the Family Grateloupiaceae Emend. (Halymeniales, Rhodophyta) Based on a Multigene Phylogeny and Comparative Reproductive Morphology

2021 ◽  
Vol 9 ◽  
Author(s):  
Su Yeon Kim ◽  
Hyung Woo Lee ◽  
Eun Chan Yang ◽  
Sung Min Boo ◽  
Juan Lopez-Bautista ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Complex Iii ◽  
Outer Cortex ◽  
Data Set ◽  
Auxiliary Cell ◽  
The Family ◽  
Red Algal ◽  
Fusion Cell ◽  
The Many ◽  
Combined Data

The marine red algal order Halymeniales currently includes two families, the Halymeniaceae and Tsengiaceae, and consist of 38 genera and about 358 species. Phylogenetic analyses on specific taxa of the order are common, but not comprehensive, leaving the many intra-ordinal relationships within the Halymeniales unresolved. To reassess the phylogeny of the Halymeniales, we conducted extensive phylogenetic analyses based on 207 rbcL sequences and multigene analyses (rbcL, psaA, psbA, cox1, and LSU) using 47 taxa from the order. The combined data set fully supports the monophyly of the Grateloupia sensu lato clade. Phylogenetic assessment of the reproductive structures in the order using the type of auxiliary cell ampullae, pericarp origin, and tetrasporangial development characters, supports a Grateloupia sensu lato clade distinct from the Halymeniaceae exemplified by the generitype Halymenia. As a result, we propose to reinstate the family Grateloupiaceae Schmitz based on the Grateloupia sensu lato clade and including Grateloupia and eight other genera: Dermocorynus, Mariaramirezia, Neorubra, Pachymeniopsis, Kintokiocolax, Phyllymenia, Prionitis, and Yonagunia. The emended Grateloupiaceae is distinguished from the Halymeniaceae by the following three characteristics; (i) simple unbranched and unilateral type of auxiliary cell ampullae, (ii) pericarp formed densely by the fusion of secondary medullary filaments from subcortical cells and lateral ampullary filaments from a fusion cell complex, (iii) tetrasporangia originating laterally from the outer cortex. The Halymeniales comprises the monophyletic Grateloupiaceae, Halymeniaceae sensu lato (which requires further study), and the Tsengiaceae.

scholarly journals Algal Neurotoxin Biosynthesis Repurposes the Terpene Cyclase Structural Fold Into an N-prenyltransferase

2020 ◽  
Author(s):  
Jonathan R. Chekan ◽  
Shaun M. K. McKinnie ◽  
Joseph P. Noel ◽  
Bradley S. Moore
Keyword(s):  
Crystal Structure ◽  
Glutamic Acid ◽  
Kainic Acid ◽  
Domoic Acid ◽  
Marine Algae ◽  
Single Amino Acid ◽  
Binding Motif ◽  
Rational Engineering ◽  
New Family ◽  
Terpene Cyclase

AbstractPrenylation is a common biological reaction in all domains of life whereupon prenyl diphosphate donors transfer prenyl groups onto small molecules as well as large proteins. The enzymes that catalyze these biotransformations are structurally distinct from ubiquitous terpene cyclases that instead assemble terpene molecules via intramolecular rearrangements. Herein we report the structure and molecular details of a new family of prenyltransferases from marine algae that repurposes the terpene cyclase structural fold for the N-prenylation of glutamic acid during the biosynthesis of the potent neurochemicals domoic acid and kainic acid. We solved the X-ray crystal structure of the prenyltransferase found in domoic acid biosynthesis, DabA, and show distinct active site binding modifications that remodel the canonical Mg2+-binding motif. We then applied our structural knowledge of DabA and a homologous enzyme from the kainic acid biosynthetic pathway, KabA, to alter their isoprene donor specificities (geranyl versus dimethylallyl diphosphate) by a single amino acid switch. While the diatom DabA and seaweed KabA enzymes share a common evolutionary lineage, they are distinct from all other terpene cyclases, suggesting a very distant ancestor.SignificanceDomoic acid is a neurotoxin produced by marine algae that readily bioaccumulates in shellfish and significantly impacts both human and animal life. The first committed step of the biosynthesis of domoic acid is the N-prenylation of L-glutamic acid by the enzyme DabA. By solving the crystal structure of DabA, we demonstrate that this enzyme has repurposed the common terpene cyclase fold to catalyze an extremely unusual reaction, N-prenylation of an unactivated primary amine. Application of these structural insights enabled rational engineering of two N-prenyltransferase enzymes to accept alternative prenyl donors. Ultimately, these results not only expand the scope of reactions catalyzed by a terpene cyclase family member, but will help inform future domoic acid environmental monitoring efforts.

Allotanaupodidae, a new family of early derivative Parasitengona  (Acari: Prostigmata)

Zootaxa ◽  
2007 ◽  
Vol 1517 (1) ◽  
pp. 1-52 ◽  
Author(s):  
ZHI-QIANG ZHANG ◽  
QING-HAI FAN
Keyword(s):  
New Species ◽  
New Zealand ◽  
Type Species ◽  
Single Species ◽  
New Genera ◽  
Larval Stages ◽  
New Family ◽  
The Family ◽  
Single Genus ◽  
Three New Species

A new family of early derivative Parasitengona (Acari: Prostigmata), Allotanaupodidae fam. nov., is described from New Zealand based on adults and deutonymphs of two new genera and five new species and a new superfamily Allotanaupodoidea is erected to accommodate it. The new family is characterized by the absence of prodorsal trichobothria and sensory areas, the presence of one or two pairs of plates with multiple setae on C to PS rows of dorsal hysterosoma, the presence of only two pairs of genital acetabula in adults, and short, distally inserted palptarsus on the palptibia. The family consists of two subfamilies (Allotanaupodinae subfam. nov. and Paratanaupodinae subfam. nov.), with the former endemic to New Zealand. Allotanaupodinae subfam. nov. has a single genus, Allotanaupodus gen. nov., which is represented by three new species from New Zealand: Allotanaupodus williamsi sp. nov. (type species) from Kawau I., Auckland, Allotanaupodus orete sp. nov. from Orete Forest, Te Puia Hut and Allotanaupodus winksi sp. nov. from Mt. Messenger, Taranaki. The eyeless Paratanaupodinae subfam. nov. consists of two genera: Nanotanaupodus gen. nov. and Paratanaupodus Andre & Lelievre-Farjon, 1960. The type genus Paratanaupodus Andre & Lelievre-Farjon, 1960 was previously placed in the Tanaupodidae and is represented by a single species, Paratanaupodus insensus André & Lelievre-Farjon, 1960, from South America. Nanotanaupodus gen. nov. is represented by two new species from New Zealand: Nanotanaupodus andrei sp. nov. (type species) from Waituhi Saddle and Nanotanaupodus gracehallae sp. nov. from Orete Forest, Te Puia Hut. A key to superfamilies of terrestrial Parasitengona (post-larval stages) is provided, along with keys to subfamilies, genera and species of the new family.

The genus Metagoniolithon Weber-van Bosse (Corallinaceae, Rhodophyta)

1979 ◽  
Vol 27 (1) ◽  
pp. 67 ◽  
Author(s):  
SC Ducker
Keyword(s):  
Spore Germination ◽  
Coralline Algae ◽  
Cortical Tissue ◽  
Single Genus ◽  
Fusion Cell ◽  
Cell Fusions

The characters of the genus Metagoniolithon Weber-van Bosse, the single genus within the subfamily Metagoniolithoideae Johansen, are defined. The thalli are differentiated into basal crusts, genicula and intergenicula, with all the tissues displaying cell fusions but lacking secondary pit connections. Initial apical branching is dichotomous, but later the meristematic genicula produce false whorls of branches. The branches lack apical cover cells but have mucilaginous caps. The conceptacles, with their overlying mucilaginous caps, are initiated in the cortical tissue of the intergenicula. The plants are dioecious. In the cystocarpic conceptacle the fusion cell is continuous and the carpospore formation is restricted to the periphery of the fusion cell. The spermatangia develop only on the floor of the conceptacle. The uniporate roof of the tetrasporangial conceptacle is formed by the growth of filaments within the ring of developing marginal tetrasporangia. Spore germination is of the Amphiroa type. The three species are endemic and restricted to western and southern Australia: M. radiatum (Lamarck) comb. nov. is epilithic; M. stelliferum (Lamarck) Weber-van Bosse and M. chara (Lamarck) comb. nov. var, chara and var. dichotomum var, nov. are epiphytic, commonly on the seagrass Amphibolis C. Agardh. The basal crust of the epiphytic species is epiphytic on species of Hetevoderma Foslie growing on Amphibolis. The characters of the genus Metagoniolithon are compared with those of Amphiroa Lamouroux, and a key to the articulated coralline algae of southern Australia is given.

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