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Open Access Modularity of gene-regulatory networks revealed
"... in sea-star development ..."
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Problems and paradigms DOI 10.1002/bies.200800214 The origin of Metazoa: a transition from temporal to spatial cell differentiation
"... 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 ..."
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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 multicellularity through integration of pre-existing transient
choanoflagellate Salpingoeca rosetta Open Access
"... Premetazoan genome evolution and the regulation of cell differentiation in the ..."
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Premetazoan genome evolution and the regulation of cell differentiation in the
BMC Evolutionary Biology BioMed Central
, 2009
"... Research article Emergence, development and diversification of the TGF-b signalling pathway within the animal kingdom ..."
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Research article Emergence, development and diversification of the TGF-b signalling pathway within the animal kingdom
Open Access
"... Development of the larval anterior neurogenic domains of Terebratalia transversa (Brachiopoda) provides insights into the diversification of larval apical organs and the spiralian nervous system Santagata et al. ..."
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Development of the larval anterior neurogenic domains of Terebratalia transversa (Brachiopoda) provides insights into the diversification of larval apical organs and the spiralian nervous system Santagata et al.
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"... A stem-group cnidarian described from the mid-Cambrian of China and its significance for cnidarian evolution Tae-yoon Park1, Jusun Woo2, Dong-Jin Lee3, Dong-Chan Lee4, Seung-bae Lee1, Zuozhen Han5, Sung Kwun Chough1 & Duck K. Choi1 Palaeontological data of extinct groups often sheds light on the ..."
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A stem-group cnidarian described from the mid-Cambrian of China and its significance for cnidarian evolution Tae-yoon Park1, Jusun Woo2, Dong-Jin Lee3, Dong-Chan Lee4, Seung-bae Lee1, Zuozhen Han5, Sung Kwun Chough1 & Duck K. Choi1 Palaeontological data of extinct groups often sheds light on the evolutionary sequences leading to extant groups, but has failed to resolve the basal metazoan phylogeny including the origin of the Cnidaria. Here we report the occurrence of a stem-group cnidarian, Cambroctoconus orientalis gen. et sp. nov., from the mid-Cambrian of China, which is a colonial organism with calcareous octagonal conical cup-shaped skeletons. It bears cnidarian features including longitudinal septa arranged in octoradial symmetry and colonial occurrence, but lacks a jellylike mesenchyme. Such morphological characteristics suggest that the colonial occurrence with polyps of octoradial symmetry is the plesiomorphic condition of the Cnidaria and appeared earlier than the jelly-like mesenchyme during the course of evolution. 1
HYPOTHESIS Open Access
"... Cortical cytasters: a highly conserved developmental trait of Bilateria with similarities to Ctenophora ..."
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Cortical cytasters: a highly conserved developmental trait of Bilateria with similarities to Ctenophora
POSTER PRESENTATION Open Access Bayesian inference from single spikes
"... Spiking neurons appear to have evolved concurrently with the advent of animal-on-animal predation, near the onset of the Cambrian explosion 543 million years ago. We hypothesize that strong selection pressures of preda-tor-prey interactions can explain the evolution of spik-ing neurons. The fossil r ..."
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Spiking neurons appear to have evolved concurrently with the advent of animal-on-animal predation, near the onset of the Cambrian explosion 543 million years ago. We hypothesize that strong selection pressures of preda-tor-prey interactions can explain the evolution of spik-ing neurons. The fossil record and molecular phylogeny indicate that animals existed without neurons for at least 100 million years prior to the Cambrian explosion. The first animals with nervous systems may have been derived sponge larvae that started feeding in the water column [1]. We use models and computer simulations of predator-prey interactions to show that thresholding prey proxi-mity detectors can greatly improve a predator’s perfor-mance under certain ecological conditions. If a prey
RESEARCH ARTICLE Metabolic and Chaperone Gene Loss Marks the Origin of Animals: Evidence for Hsp104 and Hsp78 Chaperones
"... The evolution of animals involved acquisition of an emergent gene repertoire for gastrulation. Whether loss of genes also co-evolved with this developmental reprogramming has not yet been addressed. Here, we identify twenty-four genetic functions that are retained in fungi and choanoflagellates but ..."
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The evolution of animals involved acquisition of an emergent gene repertoire for gastrulation. Whether loss of genes also co-evolved with this developmental reprogramming has not yet been addressed. Here, we identify twenty-four genetic functions that are retained in fungi and choanoflagellates but undetectable in animals. These lost genes encode: (i) sixteen dis-tinct biosynthetic functions; (ii) the two ancestral eukaryotic ClpB disaggregases, Hsp78 and Hsp104, which function in the mitochondria and cytosol, respectively; and (iii) six other as-sorted functions. We present computational and experimental data that are consistent with a joint function for the differentially localized ClpB disaggregases, and with the possibility of a shared client/chaperone relationship between the mitochondrial Fe/S homoaconitase en-coded by the lost LYS4 gene and the two ClpBs. Our analyses lead to the hypothesis that the evolution of gastrulation-based multicellularity in animals led to efficient extraction of nutri-ents from dietary sources, loss of natural selection for maintenance of energetically expen-sive biosynthetic pathways, and subsequent loss of their attendant ClpB chaperones.
