Dynamic control of positional information in the early Drosophila embryo.
Morphogen gradients contribute to pattern formation by determining positional information in morphogenetic fields. Interpretation of positional information is thought to rely on direct, concentration-threshold-dependent mechanisms for establishing multiple differential domains of target gene expression. In Drosophila, maternal gradients establish the initial position of boundaries for zygotic gap gene expression, which in turn convey positional information to pair-rule and segment-polarity genes, the latter forming a segmental pre-pattern by the onset of gastrulation. Here we report, on the basis of quantitative gene expression data, substantial anterior shifts in the position of gap domains after their initial establishment. Using a data-driven mathematical modelling approach, we show that these shifts are based on a regulatory mechanism that relies on asymmetric gap-gap cross-repression and does not require the diffusion of gap proteins. Our analysis implies that the threshold-dependent interpretation of maternal morphogen concentration is not sufficient to determine shifting gap domain boundary positions, and suggests that establishing and interpreting positional information are not independent processes in the Drosophila blastoderm.
Jaeger
Johannes
J
Department of Applied Mathematics and Statistics, and Center for Developmental Genetics, Stony Brook University, Stony Brook, New York 11794-3600, USA.
Surkova
Svetlana
S
Blagov
Maxim
M
Janssens
Hilde
H
Kosman
David
D
Kozlov
Konstantin N
KN
Manu
Myasnikova
Ekaterina
E
Vanario-Alonso
Carlos E
CE
Samsonova
Maria
M
Sharp
David H
DH
Reinitz
John
J
D000818:Animals; D001756:Blastoderm / Q000166:cytology / Q000378:metabolism; D019521:Body Patterning; D004058:Diffusion; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008954:Models, Biological; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
D029721:Drosophila Proteins; D012333:RNA, Messenger