Candidate gene screen in the red flour beetle Tribolium reveals six3 as ancient regulator of anterior median head and central complex development.
Several highly conserved genes play a role in anterior neural plate patterning of vertebrates and in head and brain patterning of insects. However, head involution in Drosophila has impeded a systematic identification of genes required for insect head formation. Therefore, we use the red flour beetle Tribolium castaneum in order to comprehensively test the function of orthologs of vertebrate neural plate patterning genes for a function in insect head development. RNAi analysis reveals that most of these genes are indeed required for insect head capsule patterning, and we also identified several genes that had not been implicated in this process before. Furthermore, we show that Tc-six3/optix acts upstream of Tc-wingless, Tc-orthodenticle1, and Tc-eyeless to control anterior median development. Finally, we demonstrate that Tc-six3/optix is the first gene known to be required for the embryonic formation of the central complex, a midline-spanning brain part connected to the neuroendocrine pars intercerebralis. These functions are very likely conserved among bilaterians since vertebrate six3 is required for neuroendocrine and median brain development with certain mutations leading to holoprosencephaly.
Center for Molecular Physiology of the Brain (CMPB), Göttingen Center of Molecular Biology, Caspari-Haus, Georg-August-University Göttingen, Göttingen, Germany.
Nico
N
Posnien
Nikolaus Dieter Bernhard
ND
Koniszewski
Hendrikje Jeannette
HJ
Hein
Gregor
G
Bucher
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D001921:Brain / Q000254:growth & development*; D004330:Drosophila / Q000196:embryology / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques / Q000379:methods; D017344:Genes, Insect; D006257:Head / Q000254:growth & development*; D016142:Holoprosencephaly / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D054258:Neural Plate / Q000254:growth & development; D038081:Organogenesis; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid; D014231:Tribolium / Q000235:genetics* / Q000254:growth & development*; D000097607:Homeobox Protein SIX3
D005136:Eye Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000097607:Homeobox Protein SIX3