... ear axes and show that axial specification occurs well after otic placode formation in chicken. Anteroposterior (AP) rotation of the hindbrain prior to specification of this axis does not affect the normal AP orientation and morphogenesis of the inner ear. By contrast, reversing the dorsoventral (DV...

.... Taken together, these data reveal a unique requirement for Tcf3 repressor function in restricting induction of the anterior-posterior axis. * Author for correspondence (e-mail: fuchs1b@rockefeller.edu ) 15 10 2003 © 2004. 2004 Wnt Gastrulation Tcf3 Node Axis Wnt...

... the stage for analyzing the Dystroglycan complex by using the power of Drosophila molecular genetics. ‡ Author for correspondence (e-mail: hannele@u.washington.edu ) 11 10 2002 © 2003. 2003 Polarity Axis Asymmetry Oogenesis Epithelia Dystroglycan Actin Microtubule ECM...

... were known that could define polarity at earlier stages. Why should we now re-consider this view? While mechanisms of axis formation in mammals could, in principle, be unique, the evolutionary conservation of numerous other developmental processes raises the question of why mammals would have evolved...

... to develop into cells that comprise either the embryonic or the abembryonic parts of the blastocyst. Moreover, the two-cell stage blastomere that is first to divide will preferentially contribute its progeny to the embryonic part. Nevertheless, we find that the blastocyst embryonic-abembryonic axis...

... a fundamental role in establishment of the vertebrate axis. We demonstrate that the zebrafish bozozok ( boz ) locus is required at the blastula stages for formation of the embryonic shield, the equivalent of the gastrula organizer and expression of multiple organizer-specific genes. Furthermore, boz...

...Acaimo González-Reyes; Daniel St Johnston ABSTRACT The anterior-posterior axis of Drosophila originates from two symmetry-breaking steps during early oogenesis. First, one of the two pro-oocytes within the cyst of 16 germline cells is selected to become the oocyte. This cell then comes to lie...

... present evidence for a second and orthogonal axis of polarity, and show that it can be functionally separated from the A/P axis. Further, we show that the polarizing information acting in this equatorial/polar axis (Eq/Pl) is established in at least two steps – the activity of one signaling molecule...

... with either the animal or vegetal pole and thus forms a third reference point for the future axis. An array of asymmetric vegetal microtubules formed by the centro-some is essential for both the cortical rotation and the translocation of the vegetal determinants to the future dorsal side of the zygote...

...Mark Q. Martindale; Jonathan Q. Henry ABSTRACT Ctenophores are a phylum of diploblastic marine animals displaying biradial symmetry organized along an oral aboral axis. One of the apomorphic sets of adult structures in ctenophores are the eight external comb rows, which run along the oral-aboral...

...Alyssa M. Morimoto; Katherine C. Jordan; Kyria Tietze; Jessica S. Britton; Elizabeth M. O’Neill; Hannele Ruohola-Baker ABSTRACT Spatially regulated activation of the Drosophila epidermal growth factor (EGF) receptor by its ligand, Gurken, is required for establishment of the dorsal/ventral axis...

... in follicle cells at later stages leads to a defect in the anterior-posterior axis of the oocyte. * Author for correspondence 07 08 1996 © 1996 by Company of Biologists 1996 constitutively active Notch precursor cell fate oogenesis axis Drosophila In Drosophila...

...Jennifer L. Watts; Bijan Etemad-Moghadam; Su Guo; Lynn Boyd; Bruce W. Draper; Craig C. Mello; James R. Priess; Kenneth J. Kemphues ABSTRACT The generation of asymmetry in the one-cell embryo of Caenorhabditis elegans is necessary to establish the anterior-posterior axis and to ensure the proper...

... , R. K. ( 1992 ). Axis formation in the embryo of the zebrafish, Brachydanio rerio . Sem. Dev. Biol . 3 , 53 – 64 . Ho , R. K. and Kane , D. A. ( 1990 ). Cell-autonomous action of zebrafish spt-1 mutation in specific meosdermal precursors . Nature 348 , 728 – 730...

.... Central to all of these models are their definitions of the longitudinal axis and the longitudinal organization of the neural plate and neural tube. To understand the longitudinal organization of the anterior brain, we have sought to identify molecular properties that are continuous along the entire...

....3787253 Black , S. D. and Gerhart , J. C. ( 1985 ). Experimental control of the site of axis formation in Xenopus laevis eggs centrifuged before first cleavage . Dev. Biol . 108 , 310 – 324 . 10.1016/0012-1606(85)90035-1 Chu , D. T. W. and Klymkowsky , M. W...

... the overlying neuroectoderm with respect to its position along the anteroposterior axis and that Hox-2 . 9 participates in or reflects this process. As neurulation continues and individual segments form, a second phase of expression is detected in the neural tube in which high levels of Hox-2 . 9 transcripts...

... 1987 © 1987 by Company of Biologists 1987 axis spontaneous double abdomen ( sda ) Chironomus samoensis polarity u.v. irradiation centrifugation The determination of early embryonic cells frequently involves localized cytoplasmic determinants ( Freeman, 1979 ; Davidson...

...-vegetal polarity. An egg fragment that contains both animal and vegetal material will produce a fairly normal larva. However, it is not clear to what extent the oral-abpral axis is specified in embryos developing from meridional fragments. Newly available markers of the oral-aboral axis allow this issue...

...C. Louise Garbutt; Julia C. Chisholm; Martin H. Johnson The influence of cell division order on the establishment of the embryonic–abembryonic axis (EA axis) of the mouse embryo was investigated. Aggregate embryos were constructed in which a labelled cell (or pair of cells) was combined...