Anterior identity is established in chick epiblast by hypoblast and anterior definitive endoderm

被引:22
作者
Chapman, SC
Schubert, FR
Schoenwolf, GC
Lumsden, A
机构
[1] Univ London Kings Coll, MRC Ctr Dev Neurobiol, Guys Hosp, London SE1 1UL, England
[2] Univ Utah, Sch Med, Dept Anat & Neurobiol, Salt Lake City, UT 84132 USA
[3] Childrens Hlth Res Ctr, Salt Lake City, UT 84132 USA
来源
DEVELOPMENT | 2003年 / 130卷 / 21期
关键词
blastula; expression; forebrain; gastrula; head; induction; organiser; markers; patterning; specification; trunk/tail; visceral endoderm;
D O I
10.1242/dev.00712
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Previous studies of head induction in the chick have failed to demonstrate a clear role for the hypoblast and anterior definitive endoderm (ADE) in patterning the overlying ectoderm, whereas data from both mouse and rabbit suggest patterning roles for anterior visceral endoderm (AVE) and ADE. Based on similarity of gene expression patterns, fate and a dual role in 'protecting' the prospective forebrain from caudalising influences of the organiser, the chick hypoblast has been suggested to be the homologue of the mouse anterior visceral endoderm. In support of this, when transplanted to chick embryos, the rabbit AVE induces anterior markers in the chick epiblast. To re-evaluate the role of the hypoblast/ADE (lower layer) in patterning the chick ectoderm, we used rostral blastoderm isolates (RBIs) as an assay, that is, rostral regions of blastoderms transected at levels rostral to the node. RBIs are, therefore, free from the influences of Hensen's node and ingressing axial mesoderm-tissues that are able to induce Ganf, the earliest specific marker of anterior neural plate. We demonstrate, using such RBIs (or RBIs dissected to remove the lower layer with or without tissue replacement), that the hypoblast/ADE (lower layer) is required and sufficient for patterning anterior positional identity in the overlying ectoderm, leading to expression of Ganf in neuroectoderm. Our results suggest that patterning of anterior positional identity and specification of neural identity are separable events operating to pattern the rostral end of the early chick embryo. Based on this new evidence we propose a revised model for establishing anteroposterior polarity, neural specification and head patterning in the early chick that is consonant with that occurring in other vertebrates.
引用
收藏
页码:5091 / 5101
页数:11
相关论文
共 68 条
[1]   Identification of a new gene family specifically expressed in chicken embryonic stem cells and early embryo [J].
Acloque, H ;
Risson, V ;
Birot, AM ;
Kunita, R ;
Pain, B ;
Samarut, J .
MECHANISMS OF DEVELOPMENT, 2001, 103 (1-2) :79-91
[2]   Anterior patterning in mouse [J].
Beddington, RSP ;
Robertson, EJ .
TRENDS IN GENETICS, 1998, 14 (07) :277-284
[3]   Axis development and early asymmetry in mammals [J].
Beddington, RSP ;
Robertson, EJ .
CELL, 1999, 96 (02) :195-209
[4]   Endophyll orients and organizes the early head region of the avian embryo [J].
Callebaut, M ;
van Nueten, E ;
Harrisson, F ;
van Nassauw, L ;
Bortier, H .
EUROPEAN JOURNAL OF MORPHOLOGY, 1999, 37 (01) :37-52
[5]   Analysis of spatial and temporal gene expression patterns in blastula and gastrula stage chick embryos [J].
Chapman, SC ;
Schubert, FR ;
Schoenwolf, GC ;
Lumsden, A .
DEVELOPMENTAL BIOLOGY, 2002, 245 (01) :187-199
[6]   Cooperation of BMP7 and SHH in the induction of forebrain ventral midline cells by prechordal mesoderm [J].
Dale, JK ;
Vesque, C ;
Lints, TJ ;
Sampath, TK ;
Furley, A ;
Dodd, J ;
Placzek, M .
CELL, 1997, 90 (02) :257-269
[7]  
Darnell DK, 1999, DEVELOPMENT, V126, P2505
[8]   SCANNING ELECTRON-MICROSCOPY OF DEVELOPMENT OF MESODERM LAYER IN CHICK-EMBRYOS [J].
ENGLAND, MA ;
WAKELY, J .
ANATOMY AND EMBRYOLOGY, 1977, 150 (03) :291-300
[9]  
ENGLAND MA, 1984, SCANNING ELECT MICRO, V4, P2059
[10]  
ENGLAND MA, 1978, SCANNING ELECT MICRO, V2, P103