# Asterochloris

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Asterochloris
> Markdown URL: https://mediated.wiki/source/Asterochloris.md
> Source: https://en.wikipedia.org/wiki/Asterochloris
> Source revision: 1344844222
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Genus of algae

Asterochloris Scientific classification Kingdom: Plantae Division: Chlorophyta Class: Trebouxiophyceae Order: Trebouxiales Family: Trebouxiaceae Genus: Asterochloris Tscherm.-Woess, 1980 Type species Asterochloris phycobiontica Tscherm.-Woess, 1980

***Asterochloris*** is a [genus](/source/Genus) of [green algae](/source/Green_algae) in the family [Trebouxiophyceae](/source/Trebouxiophyceae). It is a common [photobiont](/source/Glossary_of_lichen_terms#photobiont) in [lichen](/source/Lichen), occurring in the [thalli](/source/Thallus) of more than 20 lichen genera worldwide. *Asterochloris* is distinguishable from the [morphologically](/source/Morphology_(biology)) similar genus *[Trebouxia](/source/Trebouxia)*, primarily due to its deeply lobed [chloroplast](/source/Chloroplast), the placement of the chloroplast along the cell's periphery before the initiation of [zoospore](/source/Zoospore) or [aplanospore](/source/Aplanospore) formation, and its tendency to primarily [reproduce asexually](/source/Asexual_reproduction) through the production of aplanospores.

## Taxonomy

The genus was [circumscribed](/source/Circumscription_(taxonomy)) in 1980 by [Elisabeth Tschermak-Woess](/source/Elisabeth_Tschermak-Woess), with *[Asterochloris phycobiontica](https://en.wikipedia.org/w/index.php?title=Asterochloris_phycobiontica&action=edit&redlink=1)* assigned as the [type species](/source/Type_species). She differentiated it from the related genus *[Trebouxia](/source/Trebouxia)* by differences in [chloroplast](/source/Chloroplast) morphology.[1] Later [molecular](/source/Molecular_phylogenetics) research showed that *Trebouxia* was [paraphyletic](/source/Paraphyletic),[2][3] and that some *Trebouxia* species were closely related to genus *Asterochloris*.[4][5][6] In 2010, Škaloud and Peksa proposed to split the genus *Trebouxia* and formally delineate genus *Asterochloris*.[7]

Within the broader classification of green algae, *Asterochloris* belongs to the order [Trebouxiales](/source/Trebouxiales) within the class [Trebouxiophyceae](/source/Trebouxiophyceae). Current research suggests that several cryptic species within the genus still await formal description.[8]

## Description

*Asterochloris* is characterised by its unique cellular structure and reproduction methods. Each *Asterochloris* cell is spherical and exists in isolation, containing a single [nucleus](/source/Cell_nucleus). The cell wall is thin and firm, lacking the gelatinous texture often found in similar organisms. Inside, there is a single [chloroplast](/source/Chloroplast)—the component responsible for [photosynthesis](/source/Photosynthesis)—shaped like a thick cup with edges that resemble the rays of a star, and it may contain one or multiple [pyrenoids](/source/Pyrenoid). Pyrenoids are specialised structures within the chloroplast that play a crucial role in the synthesis of [starch](/source/Starch). These pyrenoids are encircled by grains of starch, suggesting an active photosynthetic machinery.[1]

Additionally, the cells of *Asterochloris* frequently contain clear, oily droplets, which are likely used as energy storage. Unlike some algae that reproduce through the production of autosporous (self-generating) spores, *Asterochloris* propagates through the release of [zoospores](/source/Zoospore) or [aplanospores](/source/Aplanospore). These spores are produced through successive [cell divisions](/source/Cell_division).[1]

In 2015, Skaloud and Peksa updated the description of *Asterochloris*, providing more detailed insights into its cellular features and reproductive behaviours. They observed that, in addition to being spherical, cells of *Asterochloris* can also be oval or pear-shaped, and the cell wall, while generally thin, may have localized areas of thickening. The nucleus of each cell is positioned along the side within a large fold of the chloroplast, a green structure critical for photosynthesis that has a star-like shape with lobes extending to the cell's edge. Central to the chloroplast are one to several pyrenoids, structures essential for starch production, surrounded by a noticeable layer of starch, indicating the cell's active energy production.[9]

Skaloud and Peksa further detailed that before the algae reproduce asexually—either through the release of swimming spores (zoospores) or non-swimming spores (aplanospores)—the chloroplast changes shape, flattening against the cell wall. The reproduction process typically results in a large number of spores, ranging from 64 to 128, and in rare cases, the algae can produce 2 to 8 self-replicating spores (autospores). They also noted that zoospores are unique in their appearance, lacking a protective covering, being flattened from back to front, and equipped with two forward-facing flagella for movement. These zoospores carry their green chloroplast at the back, the nucleus in the middle or toward the back, and lack a clear visual receptor ([stigma](/source/Eyespot_apparatus)). When zoospores are released, they initially swim together as a group, connected at the back, before dispersing. Skaloud and Peksa also mentioned that sexual reproduction occurs but is rare, involving the merging of two similar ([isogamous](/source/Isogamy)) [gametes](/source/Gamete).[9]

## Habitat and distribution

*Asterochloris* is a widely distributed and [cosmopolitan](/source/Cosmopolitan_distribution) genus. It is a common [photobiont](/source/Glossary_of_lichen_terms#photobiont) in [lichen](/source/Lichen), occurring in the [thalli](/source/Thallus) of more than 20 lichen genera worldwide.[9] The genus associates primarily with mycobionts from the families [Cladoniaceae](/source/Cladoniaceae) and [Stereocaulaceae](/source/Stereocaulaceae).[8]

While primarily known as a lichen symbiont, free-living populations of *Asterochloris* have been documented in various environments. These include soil communities, mountain [tundra](/source/Tundra) regions, and on tree bark in sub-[Mediterranean](/source/Mediterranean_Basin) regions of Slovenia and Italy. In an unusual habitat, the genus has also been detected on the hair of [sloths](/source/Sloth) in South and Central America.[8]

## Species

- *[Asterochloris antarctica](https://en.wikipedia.org/w/index.php?title=Asterochloris_antarctica&action=edit&redlink=1)* Y.J.Kim, J.I.Kim & W.Shin, 2020[10] – Antarctica

- *[Asterochloris echinata](https://en.wikipedia.org/w/index.php?title=Asterochloris_echinata&action=edit&redlink=1)* Skaloud & Peksa[9]

- *[Asterochloris erici](https://en.wikipedia.org/w/index.php?title=Asterochloris_erici&action=edit&redlink=1)* (Ahmadjian) Skaloud & Peksa

- *[Asterochloris excentrica](https://en.wikipedia.org/w/index.php?title=Asterochloris_excentrica&action=edit&redlink=1)* (Archibald) Skaloud & Peksa

- *[Asterochloris friedlii](https://en.wikipedia.org/w/index.php?title=Asterochloris_friedlii&action=edit&redlink=1)* Skaloud & Peksa[9]

- *[Asterochloris gaertneri](https://en.wikipedia.org/w/index.php?title=Asterochloris_gaertneri&action=edit&redlink=1)* Skaloud & Peksa[9]

- *[Asterochloris glomerata](https://en.wikipedia.org/w/index.php?title=Asterochloris_glomerata&action=edit&redlink=1)* (Warén) Skaloud & Peksa

- *[Asterochloris irregularis](https://en.wikipedia.org/w/index.php?title=Asterochloris_irregularis&action=edit&redlink=1)* (Hildreth & Ahmadjian) Skaloud & Peksa

- *[Asterochloris italiana](/source/Asterochloris_italiana)* (Archibald) Skaloud & Peksa

- *[Asterochloris leprarii](https://en.wikipedia.org/w/index.php?title=Asterochloris_leprarii&action=edit&redlink=1)* Skaloud & Peksa[9]

- *[Asterochloris lobophora](https://en.wikipedia.org/w/index.php?title=Asterochloris_lobophora&action=edit&redlink=1)* Skaloud & Peksa[9]

- *[Asterochloris magnus](https://en.wikipedia.org/w/index.php?title=Asterochloris_magnus&action=edit&redlink=1)* (Archibald) Skaloud & Peksa

- *[Asterochloris mediterranea](https://en.wikipedia.org/w/index.php?title=Asterochloris_mediterranea&action=edit&redlink=1)* E.Barreno, S.Chiva, P.Moya & P.Škaloud, 2015[11] – Iberian Peninsula; Canary Islands

- *[Asterochloris phycobiontica](https://en.wikipedia.org/w/index.php?title=Asterochloris_phycobiontica&action=edit&redlink=1)* E.Tschermak-Woess

- *[Asterochloris pseudoirregularis](https://en.wikipedia.org/w/index.php?title=Asterochloris_pseudoirregularis&action=edit&redlink=1)* Y.J.Kim, J.I.Kim & W.Shin, 2020[10] – Antarctica

- *[Asterochloris pyriformis](https://en.wikipedia.org/w/index.php?title=Asterochloris_pyriformis&action=edit&redlink=1)* Thüs et al.

- *[Asterochloris sejongensis](https://en.wikipedia.org/w/index.php?title=Asterochloris_sejongensis&action=edit&redlink=1)* Kim & Shin, 2017[12] – Antarctica; *[Cladonia pyxidata](/source/Cladonia_pyxidata)*, *[Sphaerophorus globosus](/source/Sphaerophorus_globosus)*

- *[Asterochloris stereocaulonicola](https://en.wikipedia.org/w/index.php?title=Asterochloris_stereocaulonicola&action=edit&redlink=1)* Y.J.Kim, J.I.Kim & W.Shin, 2020[10] – Antarctica

- *[Asterochloris woessiae](https://en.wikipedia.org/w/index.php?title=Asterochloris_woessiae&action=edit&redlink=1)* Skaloud & Peksa[9]

## References

1. ^ [***a***](#cite_ref-Tschermak-Woess_1980_1-0) [***b***](#cite_ref-Tschermak-Woess_1980_1-1) [***c***](#cite_ref-Tschermak-Woess_1980_1-2) Tschermak-Woess, Elisabeth (1980). "*Asterochloris phycobiontica*, gen. et spec., nov., der Phycobiont der Flechte *Varicellaria carneonivea*". *Plant Systematics and Evolution* (in German). **135** (3–4): 279–294. [doi](/source/Doi_(identifier)):[10.1007/BF00983192](https://doi.org/10.1007%2FBF00983192).

1. **[^](#cite_ref-Friedl_&_Zeltner_1994_2-0)** Friedl, Thomas; Zeltner, Cornelia (1994). "Assessing the relationships of some coccoid green lichen algae and the Microthamniales (Chlorophyta) with 18s ribosomal RNA gene sequence comparisons 1". *Journal of Phycology*. **30** (3): 500–506. [Bibcode](/source/Bibcode_(identifier)):[1994JPcgy..30..500F](https://ui.adsabs.harvard.edu/abs/1994JPcgy..30..500F). [doi](/source/Doi_(identifier)):[10.1111/j.0022-3646.1994.00500.x](https://doi.org/10.1111%2Fj.0022-3646.1994.00500.x).

1. **[^](#cite_ref-Friedl_&_Rokitta_1997_3-0)** Friedl, T.; Rokitta, C. (1997). "Species relationships in the lichen alga *Trebouxia* (Chlorophyta, Trebouxiophyceae): molecular phylogenetic analyses of nuclear-encoded large subunit rRNA gene sequences". *Symbiosis*. **23**: 125–148.

1. **[^](#cite_ref-Helms_et_al._2001_4-0)** Helms, Gert; Friedl, Thomas; Rambold, Gerhard; Mayrhofer, Helmut (2001). "Identification of photobionts from the lichen family Physciaceae using algal-specific ITS rDNA sequencing". *The Lichenologist*. **33** (1): 73–86. [doi](/source/Doi_(identifier)):[10.1006/lich.2000.0298](https://doi.org/10.1006%2Flich.2000.0298).

1. **[^](#cite_ref-Piercey-Normore_&_DePriest_2001_5-0)** Piercey-Normore, Michele D.; DePriest, Paula T. (2001). "Algal switching among lichen symbioses". *American Journal of Botany*. **88** (8): 1490–1498. [doi](/source/Doi_(identifier)):[10.2307/3558457](https://doi.org/10.2307%2F3558457). [JSTOR](/source/JSTOR_(identifier)) [3558457](https://www.jstor.org/stable/3558457). [PMID](/source/PMID_(identifier)) [21669682](https://pubmed.ncbi.nlm.nih.gov/21669682).

1. **[^](#cite_ref-Škaloud_&_Peksa_2008_6-0)** Škaloud, Pavel; Peksa, Ondřej (2008). ["Comparative study of chloroplast morphology and ontogeny in *Asterochloris* (Trebouxiophyceae, Chlorophyta)"](https://botany.natur.cuni.cz/skaloud/soubory/publikace/2008_Skaloud_Peksa.pdf) (PDF). *Biologia*. **63** (6): 873–880. [Bibcode](/source/Bibcode_(identifier)):[2008Biolg..63..873S](https://ui.adsabs.harvard.edu/abs/2008Biolg..63..873S). [doi](/source/Doi_(identifier)):[10.2478/s11756-008-0115-y](https://doi.org/10.2478%2Fs11756-008-0115-y).

1. **[^](#cite_ref-Skaloud_&_Peksa_2010_7-0)** Skaloud, Pavel; Peksa, Ondrej (2010). ["Evolutionary inferences based on ITS rDNA and actin sequences reveal extensive diversity of the common lichen alga *Asterochloris* (Trebouxiophyceae, Chlorophyta)"](https://botany.natur.cuni.cz/algo/soubory/publikace/2010-Skaloud-Peksa.pdf) (PDF). *Molecular Phylogenetics and Evolution*. **54** (1): 36–46. [doi](/source/Doi_(identifier)):[10.1016/j.ympev.2009.09.035](https://doi.org/10.1016%2Fj.ympev.2009.09.035). [PMID](/source/PMID_(identifier)) [19853051](https://pubmed.ncbi.nlm.nih.gov/19853051).

1. ^ [***a***](#cite_ref-Veselá_et_al._2024_8-0) [***b***](#cite_ref-Veselá_et_al._2024_8-1) [***c***](#cite_ref-Veselá_et_al._2024_8-2) Veselá, Veronika; Malavasi, Veronica; Škaloud, Pavel (2024). ["A synopsis of green-algal lichen symbionts with an emphasis on their free-living lifestyle"](https://doi.org/10.1080%2F00318884.2024.2325329). *Phycologia*. **63** (3): 317–338. [doi](/source/Doi_(identifier)):[10.1080/00318884.2024.2325329](https://doi.org/10.1080%2F00318884.2024.2325329). [hdl](/source/Hdl_(identifier)):[11577/3511125](https://hdl.handle.net/11577%2F3511125).

1. ^ [***a***](#cite_ref-Škaloud_et_al._2015_9-0) [***b***](#cite_ref-Škaloud_et_al._2015_9-1) [***c***](#cite_ref-Škaloud_et_al._2015_9-2) [***d***](#cite_ref-Škaloud_et_al._2015_9-3) [***e***](#cite_ref-Škaloud_et_al._2015_9-4) [***f***](#cite_ref-Škaloud_et_al._2015_9-5) [***g***](#cite_ref-Škaloud_et_al._2015_9-6) [***h***](#cite_ref-Škaloud_et_al._2015_9-7) [***i***](#cite_ref-Škaloud_et_al._2015_9-8) Škaloud, Pavel; Steinová, Jana; Řídká, Tereza; Vančurová, Lucie; Peksa, Ondřej (2015). "Assembling the challenging puzzle of algal biodiversity: species delimitation within the genus *Asterochloris* (Trebouxiophyceae, Chlorophyta)". *Journal of Phycology*. **51** (3): 507–527. [Bibcode](/source/Bibcode_(identifier)):[2015JPcgy..51..507S](https://ui.adsabs.harvard.edu/abs/2015JPcgy..51..507S). [doi](/source/Doi_(identifier)):[10.1111/jpy.12295](https://doi.org/10.1111%2Fjpy.12295). [PMID](/source/PMID_(identifier)) [26986666](https://pubmed.ncbi.nlm.nih.gov/26986666).

1. ^ [***a***](#cite_ref-Kim_et_al._2020_10-0) [***b***](#cite_ref-Kim_et_al._2020_10-1) [***c***](#cite_ref-Kim_et_al._2020_10-2) Kim, Jong Im; Kim, Yong Jun; Nam, Seung Won; So, Jae Eun; Hong, Soon Gyu; Choi, Han-Gu; Shin, Woongghi (2020). ["Taxonomic study of three new Antarctic *Asterochloris* (Trebouxiophyceae) based on morphological and molecular data"](https://doi.org/10.4490%2Falgae.2020.35.2.23). *Algae*. **35** (1): 17–32. [doi](/source/Doi_(identifier)):[10.4490/algae.2020.35.2.23](https://doi.org/10.4490%2Falgae.2020.35.2.23).

1. **[^](#cite_ref-Moya_et_al._2015_11-0)** Moya, Patricia; Škaloud, Pavel; Chiva, Salvador; García-Breijo, Francisco J.; Reig-Armiñana, José; Vančurová, Lucie; Barreno, Eva (2015). "Molecular phylogeny and ultrastructure of the lichen microalga *Asterochloris mediterranea* sp. nov. from Mediterranean and Canary Islands ecosystems". *International Journal of Systematic and Evolutionary Microbiology*. **65** (Pt_6): 1838–1854. [doi](/source/Doi_(identifier)):[10.1099/ijs.0.000185](https://doi.org/10.1099%2Fijs.0.000185). [hdl](/source/Hdl_(identifier)):[10251/68891](https://hdl.handle.net/10251%2F68891). [PMID](/source/PMID_(identifier)) [25757706](https://pubmed.ncbi.nlm.nih.gov/25757706).

1. **[^](#cite_ref-Kim_et_al._2017_12-0)** Kim, Jong Im; Nam, Seung Won; So, Jae Eun; Hong, Soon Gyu; Choi, Han-Gu; Shin, Woongghi (2017). ["Asterochloris sejongensis sp. nov. (Trebouxiophyceae, Chlorophyta) from King George Island, Antarctica"](https://repository.kopri.re.kr/bitstream/201206/5850/1/349151.pdf) (PDF). *Phytotaxa*. **295** (1): 60–70. [doi](/source/Doi_(identifier)):[10.11646/phytotaxa.295.1.5](https://doi.org/10.11646%2Fphytotaxa.295.1.5).

Taxon identifiers Asterochloris Wikidata: Q84403360 Wikispecies: Asterochloris AlgaeBase: 45140 GBIF: 2642029 iNaturalist: 202576 IRMNG: 1107820 NCBI: 291965 Open Tree of Life: 84514 WoRMS: 601375

---
Adapted from the Wikipedia article [Asterochloris](https://en.wikipedia.org/wiki/Asterochloris) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Asterochloris?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.