Elongatocystis

Last updated

Elongatocystis
Scientific classification OOjs UI icon edit-ltr.svg
Clade: Viridiplantae
Division: Chlorophyta
Class: Trebouxiophyceae
Order: Chlorellales
Family: Oocystaceae
Genus: Elongatocystis
Krienitz & C. Bock, 2011
Species:
E. ecballocystiformis
Binomial name
Elongatocystis ecballocystiformis
Krienitz & C. Bock, 2011

Elongatocystis is an autotrophic green alga in the Oocystaceae family that is defined by its elongated type cell. This genus was discovered in a rockpool at Belvedere River, Mpumalanga, South Africa and described by Krienitz and Bock in 2011 along with two other strains of Oocystaceae. Its discovery and genetic analysis determined that Oocystis ecballocystiformis should be removed. In its place, the genus Elongatocystis was proposed to more accurately represent the phylogenetic tree. [1]

Contents

Morphologically, the cells of Elongatocystis are elongated and occasionally bent-shaped. It is surrounded by a mucilaginous envelope and has smooth cell walls that are uniform in thickness. Elongatocystis is known to possess around 1 to 4 chloroplasts in each cell, which commonly results in some thickening in the central region where it may interconnect with other chloroplasts. The vegetative cells, or actively growing cells, are approximately 8–16 × 3–8 μm in size and reproduce asexually through autosporulation. Elongatocystis cells exhibiting the bent boomerang shape are observed with divided nuclei and chloroplasts suggesting that its morphology aids in the division process. [1]

Elongatocystis is closely related to Ecballocystis , through 18S rDNA phylogeny, which is also a part of the Oocystaceae family. [2] Additionally, the elongated shape of its cell could be attributed to a deformation or its relation to the genus Planctonema which could have further implications for the Oocystaceae. [1]

Etymology

The name for Elongatocystis is derived from its elongated type cell, with elongatus derived from Latin for elongated and cysta meaning cyst. It was coined by Krienitz and Bock in order to accommodate for Oocystis ecballocystiformis. [1]

History of knowledge

Elongatocystis was first observed by Krienitz and Bock through an article published in 2011 detailing three new strains of Oocystaceae that were collected in inland waters of Africa. Specifically, Elongatocystis was collected in a rockpool at Belvedere River, Mpumalanga, South Africa. The samples were isolated from the water samples by microcapillaries following the collection and were grown in suspensions under a 14 hour to 10 hour light-dark schedule. The morphology of each strain was observed using light microscopy with differential interference contrast. A polymerase chain reaction (PCR) test was also performed in order to compare the gene sequences of the three strains against other Oocystaceae sequences obtained from the GenBank database. To determine where each organism would lie on the phylogenetic tree, maximum likelihood (ML), maximum parsimony (MP), distance (neighborjoining; NJ), and Bayesian analyses (MB) methods were used. These tests resulted in the distinguishing of Elongatocystis from the rest of the Oocystaceae family. Currently, Elongatocystis ecballocystiformis is the sole species in the genus. [1]

Habitat and ecology

Elongatocystis was first found in a rockpool at Belvedere River, Mpumalanga, South Africa. It is an autotrophic alga that resides in inland waters which suggests it is a primary producer in its ecological habitat and likely plays a role in the food web of other organisms. [1]

Description of the organism

Morphology

Elongatocystis has a vivid green colour and a jelly-like consistency. Its cells have a smooth wall and are elongated in shape. It is also covered by a thick mucilaginous envelope which surrounds the cells. However, this envelope can be absent depending on the stage of the cell. The vegetative cells of Elongatocystis are broadly oval in shape with uniform thickness spanning the membrane. These cells are observed to be approximately 8–16 × 3–8 μm in size. Many cells assimilate particles and oil droplets are observed in the daughter cells along with one to two parietal pyrenoid-bearing through-shaped chloroplasts. These chloroplasts can be thickened in the central area where it has interconnections with another. Elongatocystis bent-shaped and elongated cells are hypothesised to be due to deformation or its relation to the genus Planctonema. [1]

Life cycles

Elongatocystis reproduces asexually with the mother cells each producing two, four, or eight autospores which then again propagate inside the mother cells, forming large grandmother cells. The grandmother cells house mother cells undergoing different developmental stages. Though Elongatocystis are most often solitary cells, they have also been observed to form colonies, usually with 2–4–8 daughter cells. [3] Elongated, bent cells were also observed with divided nuclei and chloroplasts but no autospores. This bent shape is theorised to have some functional benefit in the process of division. No sexual reproduction is observed in Elongatocystis. [1]

Genetics

Elongatocystis is closely related to Ecballocystis in 18s rRNA phylogeny and has an established sister lineage with Crucigeniella rectangularis and Makinoella tosaensis . [2]

Practical importance

The genus Elongatocystis was first formed in order to accommodate the former Oocystis ecballocystiformis. The separation of Elongatocystis from Oocystis raised uncertainty regarding diversity and genetic classification for the Oocystaceae family. This suggests that further taxonomic studies are required in order to accurately determine the placement of Oocystaceae family in the phylogenetic tree. [4] Other than the implications it has on the Oocystaceae family, Elongatocystis has no other discovered practical importance.

Related Research Articles

<span class="mw-page-title-main">Hydrodictyaceae</span> Family of algae

Hydrodictyaceae is a family of green algae in the order Sphaeropleales. They are found in freshwater habitats worldwide.

<span class="mw-page-title-main">Botryococcaceae</span> Family of algae

Botryococcaceae is a family of green algae in the class Trebouxiophyceae.

<span class="mw-page-title-main">Chlorellaceae</span> Family of algae

Chlorellaceae are a family of green algae in the order Chlorellales. About 250 species are currently accepted in the family. Members of the family are distributed worldwide and are common in a variety of freshwater, terrestrial and marine environments.

<span class="mw-page-title-main">Oocystaceae</span> Family of algae

Oocystaceae is a family of green algae, in the class Trebouxiophyceae. Molecular phylogenetic studies mostly place the family in the order Chlorellales, as sister to Chlorellaceae. The type genus is Oocystis.

<span class="mw-page-title-main">Selenastraceae</span> Family of algae

Selenastraceae is a family of green algae in the order Sphaeropleales. Members of this family are common components of the phytoplankton in freshwater habitats worldwide. A few species have been found in brackish and marine habitats, such as in the Baltic Sea.

<i>Actinastrum</i> Genus of algae

Actinastrum is a genus of freshwater green algae. It was first described by Gustaf Lagerheim in 1882. Members of the genus are commonly found in eutrophic freshwater ponds and lakes, and have a cosmopolitan distribution.

Dictyochloropsis is a genus of unicellular green alga of the phylum Chlorophyta. This genus consists of free-living algae which have a reticulate (net-like) chloroplast that varies slightly in morphology between species, and that when mature always lacks a pyrenoid. Dictyochloropsis is asexual and reproduces using autospores.

<i>Dictyosphaerium</i> Genus of algae

Dictyosphaerium is a genus of green algae, in the family Chlorellaceae. It occurs in freshwater habitats around the world and is planktonic. The name comes from the Greek roots diktyon, meaning "net", and sphaira, meaning "ball", referring to its morphology.

<i>Elliptochloris</i> Genus of algae

Elliptochloris is a genus of green algae in the order Prasiolales. Species of this genus are common and found in a variety of terrestrial habitats such as soils. Some species in the genus are photobiont partners in lichens. One species, E. marina, is a symbiont within two species of sea anemone, Anthopleura elegantissima and A. xanthogrammica. It seems to have a worldwide distribution.

<i>Eremosphaera</i> Genus of algae

Eremosphaera is a genus of green algae in the family Oocystaceae. It was first described by Heinrich Anton de Bary in 1858, who thought it was a desmid. Since then, many authors have debated its classification, until its modern placement in the family Oocystaceae.

<i>Lagerheimia</i> Genus of algae

Lagerheimia is a genus of green algae in the family Oocystaceae. It is commonly found in freshwater habitats all over the world, although some species are rare and have only been recorded from Europe or the United States.

<i>Mychonastes</i> Genus of algae

Mychonastes is a genus of green algae, specifically of the Chlorophyceae. It is the sole genus of the family Mychonastaceae.

Pseudomuriella is a genus of green algae, specifically of the class Chlorophyceae. It is the sole genus of the family Pseudomuriellaceae. It is a terrestrial alga that inhabits soils.

<i>Selenastrum</i> Genus of algae

Selenastrum is a genus of green algae in the family Selenastraceae. It is common in freshwater habitats around the world. Most species prefer temperate or warm-temperate waters.

<i>Crucigenia</i> Genus of algae

Crucigenia is a genus of green algae in the class Trebouxiophyceae. It is widespread, but not often abundant, in freshwater habitats around the world.

<i>Tetrastrum</i> Genus of algae

Tetrastrum is a genus of green algae (Chlorophyta). It is a common component of the phytoplankton of freshwater habitats, particularly eutrophic and alkaline waters.

Chlorella volutis is a species of euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped, is solitary and lacks a mucilaginous envelope.

Chlorella rotunda is a euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped, is solitary and lacks a mucilaginous envelope.

Chlorella lewinii is a euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped, is solitary and lacks a mucilaginous envelope.

<i>Mucidosphaerium pulchellum</i> Species of algae

Mucidosphaerium pulchellum, also known by its synonym Dictyosphaerium pulchellum, is a species of freshwater green algae, in the family Chlorellaceae.

References

  1. 1 2 3 4 5 6 7 8 Krienitz, Lothar; Bock, Christina (2011). "Elongatocystis ecballocystiformis gen. et comb. nov., and some reflections on systematics of Oocystaceae (Trebouxiophyceae, Chlorophyta)". Fottea. 11 (2): 271–278. doi: 10.5507/fot.2011.026 via Research Gate.
  2. 1 2 Xia, Shuang; Zhu, Huan; Cheng, Ying–Yin; Liu, Guo–Xiang; Hu, Zheng–Yu (2013). "Phylogenetic position of Ecballocystis and Ecballocystopsis (Chlorophyta)" (PDF). Fottea. 13 (1): 65–75. doi:10.5507/fot.2013.006. S2CID   4006189 via Czech Phycology.
  3. Liu, Xudong; Wang, Qinghua; Zhu, Huan; Liu, Benwen; Rindi, Fabio; Liu, Guoxiang; Xie, Shulian; Hu, Zhengyu (2020). "Reticulocystis yunnanense gen. et sp. nov., a new member of freshwater Oocystaceae algae (Trebouxiophyceae, Chlorophyta)". European Journal of Phycology. 55 (4): 507–516. doi:10.1080/09670262.2020.1751303. S2CID   225843100 via Taylor and Francis.
  4. Lenka, Stenclova; Fucikova, Karolina; Kastovsky, Jan; Pazoutova, Marie (2017). "Molecular and morphological delimitation and generic classification of the family Oocystaceae (Trebouxiophyceae, Chlorophyta)". Journal of Phycology. 53 (6): 1263–1282. doi:10.1111/jpy.12581. PMID   28833138. S2CID   21278460 via Wiley Online Library.