Key roles of the Broad-Complex gene in insect embryogenesis.
The Broad-Complex (BR-C) is a primary response gene in the ecdysteroid signaling pathway which encodes a family of transcription factors that play a key role in metamorphic processes. With the aim of studying the possible functions of BR-C in the embryogenesis of a short germ band insect, we cloned BR-C cDNAs in the cockroach Blattella germanica (BgBR-C) and obtained the full coding region of six BR-C isoforms (Z1-Z6) of which, Z1-Z5 have homologous sequences in other insects, whereas Z6 is new. Temporal-expression patterns indicate that BgBR-C isoforms are present throughout the embryogenesis of B. germanica, although with weak fluctuations. Silencing all BgBR-C isoforms in the embryo through parental RNAi elicited a diversity of phenotypes. These phenotypes suggest roles for BgBR-C in different embryogenesis processes of B. germanica, mainly in the formation of the germ band, in the transition from 30% to 35% of total development, when the amnion and serosa rupture and the secondary dorsal organ is formed, and in the hatching process, which involves neural, endocrine and muscular coordination.
Piulachs
Maria-Dolors
MD
Institut de Biología Evolutiva (CSIC-UPF), Passeig Marítim 39, 08003 Barcelona, Spain. mdolors.piulachs@ibe.upf-csic.es
Pagone
Viviana
V
Bellés
Xavier
X
D000595:Amino Acid Sequence; D000818:Animals; D003058:Cockroaches / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics*; D007301:Insect Hormones / Q000378:metabolism / Q000502:physiology; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D012333:RNA, Messenger; D016415:Sequence Alignment; D015398:Signal Transduction; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*
D018076:DNA, Complementary; D007301:Insect Hormones; D019476:Insect Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D014157:Transcription Factors