The heterolobosea is almost certainly home to Acrasis however no
SSUrDNA sequence for this genera is yet available. This kinship was
suggested first by a close morphological and behavioural (locomotion
pattern) examination (Page
& Blanton, 1985;
and the class Heterolobosea was raised to unite Acrasis with the
& Blanton, 1985).
Molecular data from Glyceraldehyde-3-phosphate dehydrogenase (Roger
et al, 1996),
tubulin (Roger et
Keeling & Doolittle, 1996),
CCT chaperonins (Archibald
et al, 2002)
(Roger et al,
1999), all indicate
an affinity between Acrasis and the Heterolobosea. This
relationship is surprising given the similarity of Acrasis with Dictyostelium,
a slime mould now recognised as being related to metazoans (). It
has been noted that schizopyrenid amoeba have circular ribosomal genes (Clark
& Cross, 1988),
and that this feature is also shared with certain organisms that have
been assumed to belong to the myxomycetes (Einvik
et al, 1998),
such as Didymium. Perhaps this genus also belongs to the
heterolobosea? It has been suggested that Stachyamoeba is
also a Heterolobosean (Page,
Archibald, J. M., O'Kelly, C. J. &
Doolittle, W. F. (2002) The chaperonin genes of Jakobid-like
flagellates: Implications for eukaryotic evolution. Mol.Biol.Evol. 19,
Brown, S. & De Jonckheere, J. F.
(1999) A reevaluation of the amoeba genus Vahlkampfia based on
SSUrDNA sequences. Eur.J.Protistol. 35, 49-54.
Clark, C. G. & Cross, G. A. M.
(1988) Circular ribosomal RNA genes are a general feature of
Schizopyrenid amoebae. J.Protozool. 35, 326-329.
Einvik, C., Elde, M. & Johansen,
S. (1998) Group I twintrons: Genetic elements in myxomycete and
schizopyrenid amoeboflagellate ribosomal DNAs, J.Biotechnology. 64,
Keeling, P. J. & Doolittle, W. F.
(1996) Alpha-tubulin from early-diverging eukaryotic lineages and the
evolution of the tubulin family. Mol.Biol.Evol. 13, 1297-1305.
Page, F. C. (1978) Acrasis rosea
and the possible relationship between Acrasida and Schizopyrenida., Arch.
Protistenk. 120, 169-181.
Page, F. C. (1987) Transfer of Stachyamoeba
lipophora to the Class Heterolobosea. Arch.Protistenkd.
Page, F. C. & Blanton, R. L.
(1985) The Heterolobosea (Sarcodina: Rhizopoda), a new class uniting the
Schizopyrenida and the Acrasidae (Acrasida). Protistologica. 21,
Roger, A. J., Smith, M. W., Doolittle,
R. F. & Ford Doolittle, W. (1996) Evidence for the Heterolobosea
from phylogenetic analysis of genes encoding Glyceraldehyde-3-phosphate
dehydrogenase. J.Euk.Microbiol. 43, 475-485.
Roger, A. J., Sandblom, O., Doolittle,
W. F. & Philippe, H. (1999) An evaluation of elongation factor 1a
as a phylogenetic marker for eukaryotes. J.Mol. Evol. 16,