TY - JOUR
T1 - Feedback control of the EGFR signaling gradient
T2 - Superposition of domain-splitting events in Drosophila oogenesis
AU - Zartman, Jeremiah J.
AU - Kanodia, Jitendra S.
AU - Cheung, Lily S.
AU - Shvartsman, Stanislav Y.
PY - 2009/9/1
Y1 - 2009/9/1
N2 - The morphogenesis of structures with repeated functional units, such as body segments and appendages, depends on multi-domain patterns of cell signaling and gene expression. We demonstrate that during Drosophila oogenesis, the two-domain expression pattern of Broad, a transcription factor essential for the formation of the two respiratory eggshell appendages, is established by a single gradient of EGFR activation that induces both Broad and Pointed, which mediates repression of Broad. Two negative-feedback loops provided by the intracellular inhibitors of EGFR signaling, Kekkon-1 and Sprouty, control the number and position of Broad-expressing cells and in this way influence eggshell morphology. Later in oogenesis, the gradient of EGFR activation is split into two smaller domains in a process that depends on Argos, a secreted antagonist of EGFR signaling. In contrast to the previously proposed model of eggshell patterning, we show that the two-domain pattern of EGFR signaling is not essential for specifying the number of appendages. Thus, the processes that define the two-domain patterns of Broad and EGFR activation are distinct; their actions are separated in time and have different effects on eggshell morphology.
AB - The morphogenesis of structures with repeated functional units, such as body segments and appendages, depends on multi-domain patterns of cell signaling and gene expression. We demonstrate that during Drosophila oogenesis, the two-domain expression pattern of Broad, a transcription factor essential for the formation of the two respiratory eggshell appendages, is established by a single gradient of EGFR activation that induces both Broad and Pointed, which mediates repression of Broad. Two negative-feedback loops provided by the intracellular inhibitors of EGFR signaling, Kekkon-1 and Sprouty, control the number and position of Broad-expressing cells and in this way influence eggshell morphology. Later in oogenesis, the gradient of EGFR activation is split into two smaller domains in a process that depends on Argos, a secreted antagonist of EGFR signaling. In contrast to the previously proposed model of eggshell patterning, we show that the two-domain pattern of EGFR signaling is not essential for specifying the number of appendages. Thus, the processes that define the two-domain patterns of Broad and EGFR activation are distinct; their actions are separated in time and have different effects on eggshell morphology.
KW - Argos
KW - EGFR
KW - Feedback
KW - Feedforward
KW - Kekkon-1
KW - Oogenesis
KW - Pattern formation
KW - Rhomboid
KW - Sprouty
UR - http://www.scopus.com/inward/record.url?scp=69049111013&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=69049111013&partnerID=8YFLogxK
U2 - 10.1242/dev.039545
DO - 10.1242/dev.039545
M3 - Article
C2 - 19641013
AN - SCOPUS:69049111013
SN - 0950-1991
VL - 136
SP - 2903
EP - 2911
JO - Journal of Embryology and Experimental Morphology
JF - Journal of Embryology and Experimental Morphology
IS - 17
ER -