Syntabulin, a motor protein linker, controls dorsal determination.
In amphibian and teleost embryos, the dorsal determinants (DDs) are believed to be initially localized to the vegetal pole and then transported to the prospective dorsal side of the embryo along a microtubule array. The DDs are known to activate the canonical Wnt pathway and thereby promote the expression of genes that induce the dorsal organizer. Here, by identifying the locus of the maternal-effect ventralized mutant tokkaebi, we show that Syntabulin, a linker of the kinesin I motor protein, is essential for dorsal determination in zebrafish. We found that syntabulin mRNA is transported to the vegetal pole during oogenesis through the Bucky ball (Buc)-mediated Balbiani body-dependent pathway, which is necessary for establishment of animal-vegetal (AV) oocyte polarity. We demonstrate that Syntabulin is translocated from the vegetal pole in a microtubule-dependent manner. Our findings suggest that Syntabulin regulates the microtubule-dependent transport of the DDs, and provide evidence for the link between AV and dorsoventral axis formation.
Laboratory for Vertebrate Axis Formation, RIKEN Center for Developmental Biology, Hyogo 650-0047, Japan.
Hideaki
H
Nojima
Sophie
S
Rothhämel
Takashi
T
Shimizu
Cheol-Hee
CH
Kim
Shigenobu
S
Yonemura
Florence L
FL
Marlow
Masahiko
M
Hibi
D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning / Q000235:genetics*; D016764:Cell Polarity / Q000235:genetics; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020409:Molecular Motor Proteins / Q000235:genetics / Q000502:physiology; D021381:Protein Transport; D023121:RNA, Messenger, Stored / Q000235:genetics / Q000502:physiology; D015027:Zebrafish / Q000196:embryology / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D023121:RNA, Messenger, Stored; D029961:Zebrafish Proteins; C548373:sybu protein, zebrafish