Abnormal nodal flow precedes situs inversus in iv and inv mice.
We examined the nodal flow of well-characterized mouse mutants, inversus viscerum (iv) and inversion of embryonic turning (inv), and found that their laterality defects are always accompanied by an abnormality in nodal flow. In a randomized laterality mutant, iv, the nodal cilia were immotile and the nodal flow was absent. In a situs inversus mutant, inv, the nodal cilia was motile but could only produce very weak leftward nodal flow. These results consistently support our hypothesis that the nodal flow produces the gradient of putative morphogen and triggers the first L-R determination event.
Okada
Y
Y
Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Japan.
Nonaka
S
S
Tanaka
Y
Y
Saijoh
Y
Y
Hamada
H
H
Hirokawa
N
N
D000818:Animals; D019521:Body Patterning; D002923:Cilia / Q000378:metabolism / Q000648:ultrastructure; D004398:Dyneins / Q000235:genetics; D005314:Embryonic and Fetal Development / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D055458:Left-Right Determination Factors; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D008863:Microspheres; D009024:Morphogenesis / Q000235:genetics; D009154:Mutation; D012857:Situs Inversus / Q000235:genetics*; D019170:Somites / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics
D055458:Left-Right Determination Factors; D016212:Transforming Growth Factor beta; D004398:Dyneins