TY - JOUR
T1 - The origin of Metazoa
T2 - A transition from temporal to spatial cell differentiation
AU - Mikhailov, Kirill V.
AU - Konstantinova, Anastasiya V.
AU - Nikitin, Mikhail A.
AU - Troshin, Peter V.
AU - Rusin, Leonid Yu
AU - Lyubetsky, Vassily A.
AU - Panchin, Yuri V.
AU - Mylnikov, Alexander P.
AU - Moroz, Leonid L.
AU - Kumar, Sudhir
AU - Aleoshin, Vladimir V.
PY - 2009
Y1 - 2009
N2 - For over a century, Haeckel's Gastraea theory remained a dominant theory to explain the origin of multicellular animals. According to this theory, the animal ancestor was a blastula-like colony of uniform cells that gradually evolved cell differentiation. Today, however, genes that typically control metazoan development, cell differentiation, cell-to-cell adhesion, and cell-to-matrix adhesion are found in various unicellular relatives of the Metazoa, which suggests the origin of the genetic programs of cell differentiation and adhesion in the root of the Opisthokonta. Multicellular stages occurring in the complex life cycles of opisthokont protists (mesomycetozoeans and choanoflagellates) never resemble a blastula. Here, we discuss a more realistic scenario of transition to multi-cellularity through integration of pre-existing transient cell types into the body of an early metazoon, which possessed a complex life cycle with a differentiated sedentary filter-feeding trophic stage and a non-feeding blastula-like larva, the synzoospore. Choanoflagellates are considered as forms with secondarily simplified life cycles.
AB - For over a century, Haeckel's Gastraea theory remained a dominant theory to explain the origin of multicellular animals. According to this theory, the animal ancestor was a blastula-like colony of uniform cells that gradually evolved cell differentiation. Today, however, genes that typically control metazoan development, cell differentiation, cell-to-cell adhesion, and cell-to-matrix adhesion are found in various unicellular relatives of the Metazoa, which suggests the origin of the genetic programs of cell differentiation and adhesion in the root of the Opisthokonta. Multicellular stages occurring in the complex life cycles of opisthokont protists (mesomycetozoeans and choanoflagellates) never resemble a blastula. Here, we discuss a more realistic scenario of transition to multi-cellularity through integration of pre-existing transient cell types into the body of an early metazoon, which possessed a complex life cycle with a differentiated sedentary filter-feeding trophic stage and a non-feeding blastula-like larva, the synzoospore. Choanoflagellates are considered as forms with secondarily simplified life cycles.
KW - Ichthyosporea
KW - Molecular phylogenetics
KW - Origin of Metazoa
KW - Rel/NF kappa B
KW - T-box family
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UR - http://www.scopus.com/inward/citedby.url?scp=70349323101&partnerID=8YFLogxK
U2 - 10.1002/bies.200800214
DO - 10.1002/bies.200800214
M3 - Article
C2 - 19472368
AN - SCOPUS:70349323101
SN - 0265-9247
VL - 31
SP - 758
EP - 768
JO - BioEssays
JF - BioEssays
IS - 7
ER -