PMID- 10393122
OWN - NLM
STAT- MEDLINE
DCOM- 19990921
LR  - 20081121
IS  - 0950-1991 (Print)
IS  - 0950-1991 (Linking)
VI  - 126
IP  - 15
DP  - 1999 Aug
TI  - MesP1 is expressed in the heart precursor cells and required for the formation of
      a single heart tube.
PG  - 3437-47
AB  - The Mesp1 gene encodes the basic HLH protein MesP1 which is expressed in the
      mesodermal cell lineage during early gastrulation. Disruption of the Mesp1 gene
      leads to aberrant heart morphogenesis, resulting in cardia bifida. In order to
      study the defects in Mesp1-expressing cells during gastrulation and in the
      specification of mesodermal cell lineages, we introduced a (beta)-galactosidase
      gene (lacZ) under the control of the Mesp1 promoter by homologous recombination. 
      The early expression pattern revealed by (beta)-gal staining in heterozygous
      embryos was almost identical to that observed by whole mount in situ
      hybridization. However, the (beta)-gal activity was retained longer than the mRNA
      signal, which enabled us to follow cell migration during gastrulation. In
      heterozygous embryos, the Mesp1-expressing cells migrated out from the primitive 
      streak and were incorporated into the head mesenchyme and heart field. In
      contrast, Mesp1-expressing cells in the homozygous deficient embryos stayed in
      the primitive streak for a longer period of time before departure. The expression
      of FLK-1, an early marker of endothelial cell precursors including heart
      precursors, also accumulated abnormally in the posterior region in
      Mesp1-deficient embryos. In addition, using the Cre-loxP site-specific
      recombination system, we could determine the lineage of the Mesp1-expressing
      cells. The first mesodermal cells that ingressed through the primitive streak
      were incorporated as the mesodermal component of the amnion, and the next
      mesodermal population mainly contributed to the myocardium of the heart tube but 
      not to the endocardium. These results strongly suggest that MesP1 is expressed in
      the heart tube precursor cells and is required for mesodermal cells to depart
      from the primitive streak and to generate a single heart tube.
FAU - Saga, Y
AU  - Saga Y
AD  - Cellular and Molecular Toxicology Division, National Institute of Health
      Sciences, Setagaya-ku, Tokyo 158, Japan. saga@nihs.go.jp
FAU - Miyagawa-Tomita, S
AU  - Miyagawa-Tomita S
FAU - Takagi, A
AU  - Takagi A
FAU - Kitajima, S
AU  - Kitajima S
FAU - Miyazaki, J i
AU  - Miyazaki Ji
FAU - Inoue, T
AU  - Inoue T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Development
JT  - Development (Cambridge, England)
JID - 8701744
RN  - 0 (Basic Helix-Loop-Helix Transcription Factors)
RN  - 0 (DNA Primers)
RN  - 0 (Mesp1 protein, mouse)
RN  - 0 (Transcription Factors)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Basic Helix-Loop-Helix Transcription Factors
MH  - Cell Movement/genetics
MH  - DNA Primers/genetics
MH  - Fetal Heart/cytology/*embryology
MH  - Gene Expression Regulation, Developmental
MH  - Genes, Reporter
MH  - Heart Defects, Congenital/genetics
MH  - Helix-Loop-Helix Motifs/genetics
MH  - In Situ Hybridization
MH  - Lac Operon
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Mice, Inbred CBA
MH  - Mice, Inbred ICR
MH  - Mice, Knockout
MH  - Mice, Transgenic
MH  - Promoter Regions, Genetic
MH  - Stem Cells/cytology
MH  - Transcription Factors/*genetics
EDAT- 1999/07/07 00:00
MHDA- 1999/07/07 00:01
CRDT- 1999/07/07 00:00
PHST- 1999/07/07 00:00 [pubmed]
PHST- 1999/07/07 00:01 [medline]
PHST- 1999/07/07 00:00 [entrez]
PST - ppublish
SO  - Development. 1999 Aug;126(15):3437-47.