Probing the Drosophila retinal determination gene network in Tribolium (II): The Pax6 genes eyeless and twin of eyeless.
The Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 is widely conserved. A rare exception is given by the larval eyes of Drosophila, which develop independently of ey and toy. To obtain insight into the origin of differential larval and adult eye regulation, we studied the function of toy and ey in the red flour beetle Tribolium castaneum. We find that single and combinatorial knockdown of toy and ey affect larval eye development strongly but adult eye development only mildly in this primitive hemimetabolous species. Compound eye-loss, however, was provoked when ey and toy were RNAi-silenced in combination with the early retinal gene dachshund (dac). We propose that these data reflect a role of Pax6 during regional specification in the developing head and that the subsequent maintenance and growth of the adult eye primordium is regulated partly by redundant and partly by specific functions of toy, ey and dac in Tribolium. The results from embryonic knockdown and comparative protein sequence analysis lead us further to conclude that Tribolium represents an ancestral state of redundant control by ey and toy.
Yang
Xiaoyun
X
Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA.
Weber
Markus
M
Zarinkamar
Nazanin
N
Posnien
Nico
N
Friedrich
Frank
F
Wigand
Barbara
B
Beutel
Rolf
R
Damen
Wim G M
WG
Bucher
Gregor
G
Klingler
Martin
M
Friedrich
Markus
M
D000595:Amino Acid Sequence; D000818:Animals; D054910:Compound Eye, Arthropod / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics*; D055785:Gene Knockdown Techniques; D053263:Gene Regulatory Networks; D018398:Homeodomain Proteins / Q000235:genetics*; D019476:Insect Proteins / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics; D014231:Tribolium / Q000196:embryology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D019476:Insect Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D015534:Trans-Activators; C113278:ey protein, Drosophila; C118464:toy protein, Drosophila