A regulatory code for neurogenic gene expression in the Drosophila embryo.
Bioinformatics methods have identified enhancers that mediate restricted expression in the Drosophila embryo. However, only a small fraction of the predicted enhancers actually work when tested in vivo. In the present study, co-regulated neurogenic enhancers that are activated by intermediate levels of the Dorsal regulatory gradient are shown to contain several shared sequence motifs. These motifs permitted the identification of new neurogenic enhancers with high precision: five out of seven predicted enhancers direct restricted expression within ventral regions of the neurogenic ectoderm. Mutations in some of the shared motifs disrupt enhancer function, and evidence is presented that the Twist and Su(H) regulatory proteins are essential for the specification of the ventral neurogenic ectoderm prior to gastrulation. The regulatory model of neurogenic gene expression defined in this study permitted the identification of a neurogenic enhancer in the distant Anopheles genome. We discuss the prospects for deciphering regulatory codes that link primary DNA sequence information with predicted patterns of gene expression.
Markstein
Michele
M
Department of Molecular and Cellular Biology, Division of Genetics and Development, 401 Barker Hall, University of California, Berkeley, CA 94720, USA.
Zinzen
Robert
R
Markstein
Peter
P
Yee
Ka-Ping
KP
Erives
Albert
A
Stathopoulos
Angela
A
Levine
Michael
M
D000818:Animals; D000852:Anopheles / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics*; D004475:Ectoderm / Q000502:physiology; D004625:Embryo, Nonmammalian / Q000502:physiology; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D008297:Male; D008648:Mesoderm / Q000502:physiology; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009420:Nervous System / Q000196:embryology; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D029721:Drosophila Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C118082:brk protein, Drosophila