name = Archamoebae

image_width = 240px
image_caption = "Entamoeba histolytica" cyst
domain = Eukaryota
regnum = Amoebozoa
phylum = Archamoebae
phylum_authority = Cavalier-Smith, 1983
subdivision_ranks = Genera
subdivision = "Endolimax"
The Archamoebae are a group of Amoebozoa distinguished by the absence of mitochondria. They include two genera, "Entamoeba" and "Endolimax", that are internal parasites or commensals of animals. A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats, and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba "Pelomyxa" has many of each.

Early molecular trees based on rRNA placed the parasitic or commensal genera (entamoebids) and the flagellate genera (pelobionts) as separate groups that diverged from other eukaryotes very early on, suggesting that the absence of mitochondria was a primitive condition. The absence of dictyosomes in "Pelomyxa" was also considered primitive, which would separate it from "Entamoeba", which has dictyosomes.

The name Archamoebae, from Greek αρχη first, refers to this presumed antiquity. However, studies based on other genes have shown that this placement is an artifact of long-branch attraction. Instead, the Archamoebae are part of the Amoebozoa that have lost their mitochondria, and are particularly close relatives of the slime moulds. It also appears the pelobionts and entamoebids are not separate groups, i.e. "Entamoeba" and "Endolimax" developed separately from free-living ancestors.

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Archamoebae — Saltar a navegación, búsqueda ? Archamoebae Quiste de Entamoeba histolytica …   Wikipedia Español

  • Archamoebae — Archéamibes …   Wikipédia en Français

  • Archéamibe — Archamoebae Archéamibes …   Wikipédia en Français

  • Amoebozoa —   Amoebozoa Rango temporal: Neoproterozoico Reciente …   Wikipedia Español

  • Amoebozoa — Taxobox fossil range = NeoproterozoicDubious|date=March 2008 Recent image width = 240px image caption = Chaos diffluens domain = Eukaryota regnum = Amoebozoa regnum authority = Lühe, 1913 emend. subdivision ranks = Subgroups subdivision =… …   Wikipedia

  • Amoebozoa — Arcella sp …   Wikipédia en Français

  • Amoebozoaire — Amoebozoa Amoebozoa …   Wikipédia en Français

  • Conosa — Scientific classification Domain: Eukaryota (unranked): Unikonta …   Wikipedia

  • Entamoeba — Taxobox color = #FFC8A0 name = Entamoeba domain = Eukaryota phylum = Amoebozoa classis = Archamoebae genus = Entamoeba subdivision ranks = Species subdivision = E. coli E. dispar E. gingivalis E. histolytica E. invadens E. moshkovskii etc.… …   Wikipedia

  • Mitochondrion — For the metal band, see Mitochondrion (band). Two mitochondria from mammalian lung tissue displaying their matrix and membranes as shown by electron microscopy …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.