Disruption of the talin gene arrests mouse development at the gastrulation stage.
Studies on cultured cells show that the cytoskeletal protein talin plays a key role in cell spreading and the assembly of cell-extracellular matrix junctions. To examine the role of talin in vivo, we have generated mice with a targeted disruption of the talin gene. Heterozygotes are normal, but no surviving homozygous mutant animals were obtained, proving that talin is required for embryogenesis. Mutant embryos develop normally to the blastocyst stage and implant, but there is a gross disorganization of the embryos at gastrulation (6.5-7.5 days post coitum), and they die around 8.5-9.5 days post coitum. The embryonic ectoderm is reduced in size, with fewer cells, and is incompletely organised compared with wild-type embryos. The mutant embryos show disorganised extraembryonic tissues, and the ectoplacental and excocoelomic cavities are not formed. This seems to be because embryonic mesoderm accumulates as a mass on the posterior side of the embryos and fails to migrate to extraembryonic regions, although mesodermal cells are evident in the embryo proper. Spreading of trophoblast cells derived from cultured mutant blastocysts on fibronectin and laminin is also considerably reduced. Therefore, the fundamental deficit in these embryos seems to be a failure of cell migration at gastrulation.
Monkley
S J
SJ
Department of Biochemistry, University of Leicester, University Road, Leicester, United Kingdom.
Zhou
X H
XH
Kinston
S J
SJ
Giblett
S M
SM
Hemmings
L
L
Priddle
H
H
Brown
J E
JE
Pritchard
C A
CA
Critchley
D R
DR
Fässler
R
R
D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000166:cytology; D002448:Cell Adhesion; D002455:Cell Division; D002465:Cell Movement / Q000235:genetics; D002478:Cells, Cultured; D002678:Chimera; D005314:Embryonic and Fetal Development; D005260:Female; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D005775:Gastrula / Q000166:cytology / Q000502:physiology*; D015870:Gene Expression; D018390:Gene Targeting; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D007797:Laminin / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D011247:Pregnancy; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D016608:Talin / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014327:Trophoblasts / Q000378:metabolism; D000098908:Brachyury Protein
D005326:Fetal Proteins; D005353:Fibronectins; D019812:Heparan Sulfate Proteoglycans; D007797:Laminin; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D020825:T-Box Domain Proteins; D016608:Talin; D000098908:Brachyury Protein; C094335:H19 long non-coding RNA; C071927:perlecan