Ultrastructure of cell division in the unicellular red alga Porphyridium purpureum

Mitosis in the unicellular red alga Porphyridium purpureum was studied with the electron microscope. During early prophase two bipartite nucleus associated organelles (NAOs) are seen in a region that will become one of the division poles. The division axis is established by the migration of one NAO. Microbodies are associated with the poles throughout the mitotic cycle. At prometaphase the nuclear envelope (NE) subjacent to each NAO forms a nuclear pocket which breaks down or opens to form a large gap. Concomitant with polar gap formation the large NAO portion proximal to the NE disperses whereas the smaller distal NAO portion remains throughout subsequent mitotic stages. At metaphase a plate arrangement of chromatin is seen and indistinct kinetochores are associated with a single microtubule. Chromatin moves to the poles followed by pronounced interzonal midpiece (IZM) elongation. After IZM abscission the nuclei migrate to opposite ends of the elongating cell. Cytokinesis occurs by means of an ingrowing cleavage furrow. A comparison of mitotic ultrastructural characteristics in Porphyridium with data available on mitosis in other red algae suggests that structural diversity may be of taxonomic significance; a comparison with other lower eukaryotes suggests that the overall features of mitosis in red algae do not support the general belief that this group is one of the most primitive of all eukaryotes.

Download Full-text

An ultrastructural study of cell division in the coralline red alga Bossiella orbigniana

Canadian Journal of Botany ◽

10.1139/b93-048 ◽

1993 ◽

Vol 71 (3) ◽

pp. 434-446 ◽

Cited By ~ 2

Author(s):

Sharon Broadwater ◽

Joe Scott ◽

Dawn Field ◽

Bill Saunders ◽

Jewel Thomas

Keyword(s):

Cell Division ◽

Red Algae ◽

Polar Region ◽

Algal Cell ◽

Metaphase Plate ◽

Red Alga ◽

Nucleolar Material ◽

Red Algal ◽

Polar Gap ◽

Rough Er

This investigation of Bossiella orbigniana (Decaisne) Silva ssp. orbigniana represents the first ultrastructural account of cell division in the order Corallinales. The mitotic process in this alga is differentiated from that of other red algae by a combination of characters. During prometaphase–metaphase the division poles contain unusual membrane arrangements including quantities of smooth-surfaced membranes and elongate extensions of perinuclear rough ER. At anaphase extensive remnants of nucleolar material attach to the chromosomes, trailing them to the poles. After telophase, the distal nucleus continues to move toward the apex resulting in much greater nuclear segregation than accomplished by anaphase alone. Cytokinesis is temporally displaced from mitosis and displaced distally from the metaphase plate. A reevaluation of ultrastructural patterns of red algal cell division suggests that there are two basic types of mitosis, the polar gap type and the polar fenestrations type to which B. orbigniana belongs. These two types are differentiated by a number of characters with the most important being the configuration of the prometaphase–metaphase polar region and spindle origin. Key words: Bossiella, cell division, Corallinales, mitosis, phylogeny, red algae.

Download Full-text

Expansion of phycobilisome linker gene families in mesophilic red algae

Nature Communications ◽

10.1038/s41467-019-12779-1 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

JunMo Lee ◽

Dongseok Kim ◽

Debashish Bhattacharya ◽

Hwan Su Yoon

Keyword(s):

Red Algae ◽

Common Ancestor ◽

Nuclear Gene ◽

Gene Families ◽

Red Alga ◽

Gene Duplications ◽

Porphyridium Purpureum ◽

The Core ◽

Photosynthetic Machinery ◽

The Common

Abstract The common ancestor of red algae (Rhodophyta) has undergone massive genome reduction, whereby 25% of the gene inventory has been lost, followed by its split into the species-poor extremophilic Cyanidiophytina and the broadly distributed mesophilic red algae. Success of the mesophile radiation is surprising given their highly reduced gene inventory. To address this latter issue, we combine an improved genome assembly from the unicellular red alga Porphyridium purpureum with a diverse collection of other algal genomes to reconstruct ancient endosymbiotic gene transfers (EGTs) and gene duplications. We find EGTs associated with the core photosynthetic machinery that may have played important roles in plastid establishment. More significant are the extensive duplications and diversification of nuclear gene families encoding phycobilisome linker proteins that stabilize light-harvesting functions. We speculate that the origin of these complex families in mesophilic red algae may have contributed to their adaptation to a diversity of light environments.

Download Full-text

Genome of the red alga Porphyridium purpureum

Nature Communications ◽

10.1038/ncomms2931 ◽

2013 ◽

Vol 4 (1) ◽

Cited By ~ 129

Author(s):

Debashish Bhattacharya ◽

Dana C. Price ◽

Cheong Xin Chan ◽

Huan Qiu ◽

Nicholas Rose ◽

...

Keyword(s):

Red Alga ◽

Porphyridium Purpureum

Download Full-text

Studies on the Regulation of Algal Growth by Gibberellin

Australian Journal of Biological Sciences ◽

10.1071/bi9711115 ◽

1971 ◽

Vol 24 (4) ◽

pp. 1115 ◽

Cited By ~ 5

Author(s):

RC Jennings

Keyword(s):

Red Algae ◽

Algal Growth ◽

Red Alga ◽

General Phenomenon ◽

Hypnea Musciformis ◽

Fast Growing ◽

High Concentrations ◽

Amo 1618 ◽

Slow Growing

CCC and Amo.1618, at relatively high concentrations only, inhibited the growth of excised branch apices of the red alga Hypnea musciformis. Neither GA3 nor GA7 stimulated growth of the alga in the presence or absence of these compounds, and gibberellin-like material extracted from H. musciformis also failed to stimulate growth. However, both gibberellins stimulated the growth of slow-growing, but not fast-growing, branch apices of the related red alga Gracilaria verucosa. It is concluded that endogenous gibberellins may not regulate the growth of H. musciformis, but this is likely to be a peculiarity of this species and not a general phenomenon in red algae.

Download Full-text

Growth and Differentiation of the Golgi Apparatus in the Red Alga, Callithamnion Roseum

Journal of Cell Science ◽

10.1242/jcs.14.3.633 ◽

1974 ◽

Vol 14 (3) ◽

pp. 633-655

Author(s):

EVA KONRAD HAWKINS

Keyword(s):

Plasma Membrane ◽

Fine Structure ◽

Golgi Apparatus ◽

Red Algae ◽

Developmental Stages ◽

Spore Wall ◽

Red Alga ◽

Wall Formation ◽

Golgi Vesicles

The fine structure of the Golgi apparatus during development of tetrasporangia of Calli-thamnion roseum is described. Dictyosomes and associated vesicles of 4 developmental stages of sporangia are examined. The wall of sporangia exhibits a heretofore unseen cuticle in red algae. Development of the spore wall and a new plasma membrane around spores occurs through fusion of adjacent Golgi vesicles along the periphery of cells. Observations are discussed in relation to wall formation and expansion of tetrads and in comparison with other work on growth and differentiation of the Golgi apparatus.

Download Full-text

Towards a general kinetic microalgae model: extending a semi-deterministic green microalgae model for the cyanobacterium Arthrospira platensis and red alga Porphyridium purpureum

Bioresource Technology ◽

10.1016/j.biortech.2021.125993 ◽

2021 ◽

pp. 125993

Author(s):

Dave Manhaeghe ◽

Larissa T. Arashiro ◽

Stijn W.H. Van Hulle ◽

Diederik P.L. Rousseau

Keyword(s):

Arthrospira Platensis ◽

Red Alga ◽

Green Microalgae ◽

Porphyridium Purpureum

Download Full-text

Cyclonerane Derivatives from the Algicolous Endophytic Fungus Trichoderma asperellum A-YMD-9-2

Marine Drugs ◽

10.3390/md17050252 ◽

2019 ◽

Vol 17 (5) ◽

pp. 252 ◽

Cited By ~ 2

Author(s):

Yin-Ping Song ◽

Feng-Ping Miao ◽

Xiang-Hong Liu ◽

Xiu-Li Yin ◽

Nai-Yun Ji

Keyword(s):

Endophytic Fungus ◽

Structural Diversity ◽

2D Nmr ◽

Red Alga ◽

Gracilaria Verrucosa ◽

Marine Phytoplankton ◽

Spectroscopic Techniques ◽

Phytoplankton Species ◽

Trichoderma Asperellum ◽

Potent Inhibition

Seven previously unreported cyclonerane derivatives, namely, 3,7,11-trihydroxycycloneran-10-one, cycloneran-3,7,10,11-tetraol, cycloneran-3,7,11-triol, 11,12,15-trinorcycloneran-3,7,10-triol, 7,10S-epoxycycloneran-3,15-diol, 7,10R-epoxycycloneran-3,15-diol, and (10Z)-15-acetoxy-10-cycloneren-3,7-diol, were isolated in addition to the known (10Z)-cyclonerotriol, (10E)-cyclonerotriol, catenioblin C, and chokol E from the culture of Trichoderma asperellum A-YMD-9-2, an endophytic fungus obtained from the marine red alga Gracilaria verrucosa. The structures of previously unreported compounds were established by spectroscopic techniques, including 1D/2D NMR, MS, and IR. The isolation of these new cyclonerane derivatives greatly adds to the structural diversity of unusual cyclonerane sesquiterpenes, and several isolates exhibit potent inhibition against some marine phytoplankton species.

Download Full-text