R7 photoreceptor specification requires Notch activity

被引:82
作者
Cooper, MTD [1 ]
Bray, SJ [1 ]
机构
[1] Univ Cambridge, Dept Anat, Cambridge CB2 3DY, England
基金
英国医学研究理事会; 英国惠康基金;
关键词
D O I
10.1016/S0960-9822(00)00826-5
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The eight photoreceptors in each ommatidium of the Drosophila eye are assembled by a process of recruitment [1,2]. First, the R8 cell is singled out, and then subsequent photoreceptors are added in pairs (R2 and R5, R3 and R4, R1 and R6) until the final R7 cell acquires a neuronal fate. R7 development requires the Sevenless receptor tyrosine kinase which is activated by a ligand from R8 [3]. Here, we report that the specification of R7 requires a second signal that activates Notch. We found that a Notch target gene is expressed in R7 shortly after recruitment. When Notch activity was reduced, the cell was misrouted to an R1/R6 fate. Conversely, when activated Notch was present in the R1/R6 cells, it caused them to adopt R7 fates or, occasionally, cone cell fates. In this context, Notch activity appears to act co-operatively, rather than antagonistically, with the receptor tyrosine kinase/Ras pathway in R7 photoreceptor specification. We propose two models: a ratchet model in which Notch would allow cells to remain competent to respond to sequential rounds of Ras signalling, and a combinatorial model in which Notch and Ras signalling would act together to regulate genes that determine cell fate.
引用
收藏
页码:1507 / 1510
页数:4
相关论文
共 24 条
[1]   Delta-1 is a regulator of neurogenesis in the vertebrate retina [J].
Ahmad, I ;
Dooley, CM ;
Polk, DL .
DEVELOPMENTAL BIOLOGY, 1997, 185 (01) :92-103
[2]   Notch signaling: Cell fate control and signal integration in development [J].
Artavanis-Tsakonas, S ;
Rand, MD ;
Lake, RJ .
SCIENCE, 1999, 284 (5415) :770-776
[3]   NOTCH IS REQUIRED FOR SUCCESSIVE CELL DECISIONS IN THE DEVELOPING DROSOPHILA RETINA [J].
CAGAN, RL ;
READY, DF .
GENES & DEVELOPMENT, 1989, 3 (08) :1099-1112
[4]   PHYLLOPOD FUNCTIONS IN THE FATE DETERMINATION OF A SUBSET OF PHOTORECEPTORS IN DROSOPHILA [J].
CHANG, HC ;
SOLOMON, NM ;
WASSARMAN, DA ;
KARIM, FD ;
THERRIEN, M ;
RUBIN, GM ;
WOLFF, T .
CELL, 1995, 80 (03) :463-472
[5]   Spatially restricted factors cooperate with Notch in the regulation of Enhancer of split genes [J].
Cooper, MTD ;
Tyler, DM ;
Furriols, M ;
Chalkiadaki, A ;
Delidakis, C ;
Bray, S .
DEVELOPMENTAL BIOLOGY, 2000, 221 (02) :390-403
[6]   Frizzled regulation of Notch signalling polarizes cell fate in the Drosophila eye [J].
Cooper, MTD ;
Bray, SJ .
NATURE, 1999, 397 (6719) :526-530
[7]  
deCelis JF, 1997, DEVELOPMENT, V124, P1919
[8]  
Dickson Barry, 1993, P1327
[9]   CONTROL OF DROSOPHILA PHOTORECEPTOR CELL FATES BY PHYLLOPOD, A NOVEL NUCLEAR-PROTEIN ACTING DOWNSTREAM OF THE RAF KINASE [J].
DICKSON, BJ ;
DOMINGUEZ, M ;
VANDERSTRATEN, A ;
HAFEN, E .
CELL, 1995, 80 (03) :453-462
[10]   Regulation of neuronal diversity in the Xenopus retina by Delta signalling [J].
Dorsky, RI ;
Chang, WS ;
Rapaport, DH ;
Harris, WA .
NATURE, 1997, 385 (6611) :67-70