365Bertocchini F, Stern CD (2002) The hypoblast of the chick embryo positions the primitive streak
by antagonizing nodal signaling. Dev Cell 3:735–744
Betchaku T, Trinkaus JP (1978) Contact relations, surface activity, and cortical microfilaments of
marginal cells of the enveloping layer and of the yolk syncytial and yolk cytoplasmic layers of
Fundulus before and during epiboly. J Exp Zool 206:381–426
Birsoy B, Kofron M, Schaible K, Wylie C, Heasman J (2006) Vg1 is an essential signaling mole-
cule in Xenopus development. Development 133:15–20
Blum M, Gaunt SJ, Cho KW, Steinbeisser H, Blumberg B, Bittner D, De Robertis EM (1992)
Gastrulation in the mouse: the role of the homeobox gene goosecoid. Cell 69:1097–1106
Bolker JA (1993a) Gastrulation and mesoderm morphogenesis in the white sturgeon. J Exp Zool
266:116–131
Bolker JA (1993b) The mechanism of gastrulation in the white sturgeon. J Exp Zool
266:132–145
Born J, Geithe HP, Tiedemann H, Kocher-Becker U (1972) Isolation of a vegetalizing inducing
factor. Hoppe Seylers Z Physiol Chem 353:1075–1084
Braem F (1895) Was ist ein Keimblatt? Biol Centralbl 15:427–506
Branford WW, Yost HJ (2002) Lefty-dependent inhibition of nodal- and wnt-responsive organizer
gene expression is essential for normal gastrulation. Curr Biol 12:2136–2141
Brauckmann S (2012) Karl Ernst von Baer (1792–1876) and evolution. Int J Dev Biol
56:653–660
Brawand D, Wahli W, Kaessmann H (2008) Loss of egg yolk genes in mammals and the origin of
lactation and placentation. PLoS Biol 6:e63
Brennan J, Lu CC, Norris DP, Rodriguez TA, Beddington RS, Robertson EJ (2001) Nodal signal-
ling in the epiblast patterns the early mouse embryo. Nature 411:965–969
Bruce AE, Howley C, Dixon Fox M, Ho RK (2005) T-box gene eomesodermin and the homeobox-
containing Mix/Bix gene mtx2 regulate epiboly movements in the zebrafish. Dev Dyn
233:105–114
Burdsal CA, Flannery ML, Pedersen RA (1998) FGF-2 alters the fate of mouse epiblast from
ectoderm to mesoderm in vitro. Dev Biol 198:231–244
Callebaut M, Van Nueten E (1994) Rauber’s (Koller’s) sickle: the early gastrulation organizer of
the avian blastoderm. Eur J Morphol 32:35–48
Callebaut M, Van Nueten E, Bortier H, Harrisson F (2003) Positional information by Rauber’s
sickle and a new look at the mechanisms of primitive streak initiation in avian blastoderms.
J Morphol 255:315–327
Callebaut M, van Nueten E, Bortier H, Harrisson F, van Nassauw L (1996) Map of the Anlage
fields in the avian unincubated blastoderm. Eur J Morphol 34:347–361
Cao Y, Zhao J, Sun Z, Zhao Z, Postlethwait J, Meng A (2004) fgf17b, a novel member of Fgf fam-
ily, helps patterning zebrafish embryos. Dev Biol 271:130–143
Cha YR, Takahashi S, Wright CV (2006) Cooperative non-cell and cell autonomous regulation of
Nodal gene expression and signaling by Lefty/Antivin and Brachyury in Xenopus. Dev Biol
290:246–264
Chandrasekharan NM (1966) In vitro vital staining of chelonian blastoderms. Indian J Exp Biol
4:131–134
Chang C, Wilson PA, Mathews LS, Hemmati-Brivanlou A (1997) A Xenopus type I activin recep-
tor mediates mesodermal but not neural specification during embryogenesis. Development
124:827–837
Chen C, Ware SM, Sato A, Houston-Hawkins DE, Habas R, Matzuk MM, Shen MM, Brown CW
(2006) The Vg1-related protein Gdf3 acts in a Nodal signaling pathway in the pre-gastrulation
mouse embryo. Development 133:319–329
Chen S, Kimelman D (2000) The role of the yolk syncytial layer in germ layer patterning in zebraf-
ish. Development 127:4681–4689
Chen Y, Schier AF (2001) The zebrafish Nodal signal Squint functions as a morphogen. Nature
411:607–610
7 Establishment of the Vertebrate Germ Layers