Heterogeneous expression of multiple putative patterning genes by single cells from the chick hindbrain.
The metameric organization of the vertebrate hindbrain into rhombomeres appears to result from the patterned expression of several transcription factors and putative signaling molecules. We have applied a refined single-cell reverse transcription-polymerase chain reaction strategy to examine the molecular logic proposed to pattern the hindbrain at the single-cell level. This technique allows analysis of the concurrent expression of several genes within an individual cell at higher sensitivity than by in situ hybridization. Our results demonstrate that cells in rhombomere (r) 4 and r5 are heterogeneous in their expression of Hoxa-3, Hoxb-2, Sek-1, and Krox-20, suggesting that single cells are dynamically regulating their rhombomere-specific gene-expression profiles. Furthermore, the strong correlation between Sek-1 and Krox-20 expression at stage 12 was greatly diminished by stage 16, suggesting that the proposed interdependence of these two genes is present only at early stages of hindbrain development.
Kato
K
K
Division of Biology, California Institute of Technology, Pasadena 91125, USA.
O'Dowd
D K
DK
Fraser
S E
SE
Smith
M A
MA
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics; D002642:Chick Embryo; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics; D051767:Early Growth Response Protein 2; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000032:analysis / Q000235:genetics; D017403:In Situ Hybridization; D048670:MAP Kinase Kinase 4; D008856:Microscopy, Fluorescence; D020929:Mitogen-Activated Protein Kinase Kinases; D016133:Polymerase Chain Reaction; D011494:Protein Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012249:Rhombencephalon / Q000166:cytology* / Q000196:embryology*; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology; D014157:Transcription Factors / Q000235:genetics
D017931:DNA Primers; D004268:DNA-Binding Proteins; D051767:Early Growth Response Protein 2; D018398:Homeodomain Proteins; C490111:Hoxb2 protein, mouse; C513262:Hoxb4 protein, mouse; D012333:RNA, Messenger; D014157:Transcription Factors; D011494:Protein Kinases; D048670:MAP Kinase Kinase 4; C482559:MAP2K4 protein, human; C482562:Map2k4 protein, mouse; D020929:Mitogen-Activated Protein Kinase Kinases