Goosecoid misexpression alters the morphology and Hox gene expression of the developing chick limb bud.
The homeobox-containing gene goosecoid (gsc) has been implicated in a variety of embryonic processes from gastrulation to rib patterning. We have analyzed the role it plays during chick limb development. Expression is initially observed at stage 20 in a proximal-anterior-ventral domain of the early limb bud which expands during subsequent stages. Later in limb development a second domain of expression appears distally which resolves to regions which surround the condensing cartilage. In order to understand the function of gsc in limb development, we have examined the effect of misexpressing gsc throughout the limb. Two striking phenotypes are observed. The first, evident at stage 24, is an alteration in the angle of femur outgrowth from the main body axis. The second, which can be detected at day 10 of development, is an overall decrease in the size of the limb with bones that are small, misshapen and bent. These phenotypes correlate with a decrease in levels of Hox gene expression in gsc-infected limb buds. From these results we suggest that gsc may normally function to regulate growth and patterning of the limb, perhaps through regulation of Hox gene expression.
Heanue
T A
TA
Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
Johnson
R L
RL
Izpisua-Belmonte
J C
JC
Stern
C D
CD
De Robertis
E M
EM
Tabin
C J
CJ
D000818:Animals; D002356:Cartilage / Q000002:abnormalities / Q000196:embryology; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation; D005269:Femur / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D051956:Goosecoid Protein; D018398:Homeodomain Proteins / Q000235:genetics*; D018878:Limb Buds / Q000196:embryology*; D010641:Phenotype; D012097:Repressor Proteins; D012190:Retroviridae / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D051956:Goosecoid Protein; D018398:Homeodomain Proteins; C094041:Hoxa11 protein, mouse; C490939:Hoxd11 protein, mouse; C490943:Hoxd12 protein, mouse; D012097:Repressor Proteins; D014157:Transcription Factors; C099959:homeobox protein HOXA13