JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Multiple Sox genes are expressed in stem cells or in differentiating neuro-sensory cells in the hydrozoan Clytia hemisphaerica.
Evodevo
PUBLISHED: 03-02-2011
Show Abstract
Hide Abstract
The Sox genes are important regulators of animal development belonging to the HMG domain-containing class of transcription factors. Studies in bilaterian models have notably highlighted their pivotal role in controlling progression along cell lineages, various Sox family members being involved at one side or the other of the critical balance between self-renewing stem cells/proliferating progenitors, and cells undergoing differentiation.
Related JoVE Video
Somatic stem cells express Piwi and Vasa genes in an adult ctenophore: ancient association of "germline genes" with stemness.
Dev. Biol.
PUBLISHED: 07-31-2010
Show Abstract
Hide Abstract
Stem cells are essential for animal development and adult tissue homeostasis, and the quest for an ancestral gene fingerprint of stemness is a major challenge for evolutionary developmental biology. Recent studies have indicated that a series of genes, including the transposon silencer Piwi and the translational activator Vasa, specifically involved in germline determination and maintenance in classical bilaterian models (e.g., vertebrates, fly, nematode), are more generally expressed in adult multipotent stem cells in other animals like flatworms and hydras. Since the progeny of these multipotent stem cells includes both somatic and germinal derivatives, it remains unclear whether Vasa, Piwi, and associated genes like Bruno and PL10 were ancestrally linked to stemness, or to germinal potential. We have investigated the expression of Vasa, two Piwi paralogues, Bruno and PL10 in Pleurobrachia pileus, a member of the early-diverging phylum Ctenophora, the probable sister group of cnidarians. These genes were all expressed in the male and female germlines, and with the exception of one of the Piwi paralogues, they showed similar expression patterns within somatic territories (tentacle root, comb rows, aboral sensory complex). Cytological observations and EdU DNA-labelling and long-term retention experiments revealed concentrations of stem cells closely matching these gene expression areas. These stem cell pools are spatially restricted, and each specialised in the production of particular types of somatic cells. These data unveil important aspects of cell renewal within the ctenophore body and suggest that Piwi, Vasa, Bruno, and PL10 belong to a gene network ancestrally acting in two distinct contexts: (i) the germline and (ii) stem cells, whatever the nature of their progeny.
Related JoVE Video
Phylogenomics revives traditional views on deep animal relationships.
Curr. Biol.
PUBLISHED: 02-22-2009
Show Abstract
Hide Abstract
The origin of many of the defining features of animal body plans, such as symmetry, nervous system, and the mesoderm, remains shrouded in mystery because of major uncertainty regarding the emergence order of the early branching taxa: the sponge groups, ctenophores, placozoans, cnidarians, and bilaterians. The "phylogenomic" approach [1] has recently provided a robust picture for intrabilaterian relationships [2, 3] but not yet for more early branching metazoan clades. We have assembled a comprehensive 128 gene data set including newly generated sequence data from ctenophores, cnidarians, and all four main sponge groups. The resulting phylogeny yields two significant conclusions reviving old views that have been challenged in the molecular era: (1) that the sponges (Porifera) are monophyletic and not paraphyletic as repeatedly proposed [4-9], thus undermining the idea that ancestral metazoans had a sponge-like body plan; (2) that the most likely position for the ctenophores is together with the cnidarians in a "coelenterate" clade. The Porifera and the Placozoa branch basally with respect to a moderately supported "eumetazoan" clade containing the three taxa with nervous system and muscle cells (Cnidaria, Ctenophora, and Bilateria). This new phylogeny provides a stimulating framework for exploring the important changes that shaped the body plans of the early diverging phyla.
Related JoVE Video
Are Hox genes ancestrally involved in axial patterning? Evidence from the hydrozoan Clytia hemisphaerica (Cnidaria).
PLoS ONE
PUBLISHED: 01-21-2009
Show Abstract
Hide Abstract
The early evolution and diversification of Hox-related genes in eumetazoans has been the subject of conflicting hypotheses concerning the evolutionary conservation of their role in axial patterning and the pre-bilaterian origin of the Hox and ParaHox clusters. The diversification of Hox/ParaHox genes clearly predates the origin of bilaterians. However, the existence of a "Hox code" predating the cnidarian-bilaterian ancestor and supporting the deep homology of axes is more controversial. This assumption was mainly based on the interpretation of Hox expression data from the sea anemone, but growing evidence from other cnidarian taxa puts into question this hypothesis.
Related JoVE Video
Independent specialisation of myosin II paralogues in muscle vs. non-muscle functions during early animal evolution: a ctenophore perspective.
BMC Evol. Biol.
Show Abstract
Hide Abstract
Myosin II (or Myosin Heavy Chain II, MHCII) is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa) and striated muscle cells (MHCIIb). Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora.
Related JoVE Video
Maternally localized germ plasm mRNAs and germ cell/stem cell formation in the cnidarian Clytia.
Dev. Biol.
Show Abstract
Hide Abstract
The separation of the germ line from the soma is a classic concept in animal biology, and depending on species is thought to involve fate determination either by maternally localized germ plasm ("preformation" or "maternal inheritance") or by inductive signaling (classically termed "epigenesis" or "zygotic induction"). The latter mechanism is generally considered to operate in non-bilaterian organisms such as cnidarians and sponges, in which germ cell fate is determined at adult stages from multipotent stem cells. We have found in the hydrozoan cnidarian Clytia hemisphaerica that the multipotent "interstitial" cells (i-cells) in larvae and adult medusae, from which germ cells derive, express a set of conserved germ cell markers: Vasa, Nanos1, Piwi and PL10. In situ hybridization analyses unexpectedly revealed maternal mRNAs for all these genes highly concentrated in a germ plasm-like region at the egg animal pole and inherited by the i-cell lineage, strongly suggesting i-cell fate determination by inheritance of animal-localized factors. On the other hand, experimental tests showed that i-cells can form by epigenetic mechanisms in Clytia, since larvae derived from both animal and vegetal blastomeres separated during cleavage stages developed equivalent i-cell populations. Thus Clytia embryos appear to have maternal germ plasm inherited by i-cells but also the potential to form these cells by zygotic induction. Reassessment of available data indicates that maternally localized germ plasm molecular components were plausibly present in the common cnidarian/bilaterian ancestor, but that their role may not have been strictly deterministic.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.