Linked Life Data

9165120

Source:http://linkedlifedata.com/resource/pubmed/id/9165120

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1997-6-19
pubmed:databankReference
pubmed:abstractText
Vertebrate segmentation has been proposed as an evolutionary inheritance either from some metameric protostome or from a more closely related deuterostome. To address this question, we studied the developmental expression of AmphiEn, the engrailed gene of amphioxus, the closest living invertebrate relative of the vertebrates. In neurula embryos of amphioxus, AmphiEn is expressed along the anteroposterior axis as metameric stripes, each located in the posterior part of a nascent or newly formed segment. This pattern resembles the expression stripes of the segment-polarity gene engrailed, which has a key role in establishing and maintaining the metameres in embryos of Drosophila and other metameric protostomes. Later, amphioxus embryos express AmphiEn in non-metameric patterns - transiently in the embryonic ectoderm and dorsal nerve cord. Nerve cord expression occurs in a few cells approximately midway along the rostrocaudal axis and also in a conspicuous group of anterior cells in the cerebral vesicle at a level previously identified as corresponding to the vertebrate diencephalon. Compared to vertebrate engrailed expression at the midbrain/hindbrain boundary, AmphiEn expression in the cerebral vesicle is relatively late. Thus, it is uncertain whether the cerebral vesicle expression marks the rostral end of the amphioxus hindbrain; if it does, then amphioxus may have little or no homolog of the vertebrate midbrain. The segmental expression of AmphiEn in forming somites suggests that the functions of engrailed homologs in establishing and maintaining a metameric body plan may have arisen only once during animal evolution. If so, the protostomes and deuterostomes probably shared a common segmented ancestor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1723-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9165120-Amino Acid Sequence, pubmed-meshheading:9165120-Animals, pubmed-meshheading:9165120-Base Sequence, pubmed-meshheading:9165120-Chordata, Nonvertebrate, pubmed-meshheading:9165120-DNA Primers, pubmed-meshheading:9165120-DNA Probes, pubmed-meshheading:9165120-Drosophila, pubmed-meshheading:9165120-Ectoderm, pubmed-meshheading:9165120-Embryo, Nonmammalian, pubmed-meshheading:9165120-Gene Expression Regulation, Developmental, pubmed-meshheading:9165120-Gene Library, pubmed-meshheading:9165120-Homeodomain Proteins, pubmed-meshheading:9165120-Molecular Sequence Data, pubmed-meshheading:9165120-Nervous System, pubmed-meshheading:9165120-Polymerase Chain Reaction, pubmed-meshheading:9165120-Sequence Homology, Amino Acid, pubmed-meshheading:9165120-Species Specificity, pubmed-meshheading:9165120-Transcription, Genetic, pubmed-meshheading:9165120-Transcription Factors, pubmed-meshheading:9165120-Vertebrates
pubmed:year
1997
pubmed:articleTitle
Sequence and embryonic expression of the amphioxus engrailed gene (AmphiEn): the metameric pattern of transcription resembles that of its segment-polarity homolog in Drosophila.
pubmed:affiliation
Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0202, USA. lzholland@ucsd.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S.