Proboscipedia and Sex combs reduced are essential for embryonic labial palpus specification in Bombyx mori

摘要

Hox genes of proboscipedia(pb)and Sex combs reduced(Scr)and their cofactors are required for determi nation of in sect mouthpart identity and play important roles in in sect orga n morphoge nesis.However,i n the lepidoptera n in sects,in cludi ng many agricultural and forest pests,the roles of these genes in determi nation of mouthpart morphogenesis are un clear.Here we report that both BmPB(Gene ID:101740380)and BmSCR(Gene ID:692761)are essential for labial palpus specification in a lepidoptera n model in sect,the silkworm,Bombyx mori.During embry onic morphoge nesis,CRISPR/Cas9-mediated mutagenesis of BmPB induced transformation of labial palpus into thoracic leg and BmSCR mutation transformed labial palpus into maxilla.Mutagenesis of Hox-related cofactor extradenticle(BmEXD;Gene ID:692478)and its nuclear localization factor homothorax(BmHTH;Gene ID:576938425)also induced distortion of embryonic labial palpus.Furthermore,mutagenesis of each of the four genes induced severe degeneration of spigot morphogenesis,an important part of spinneret structure.Quantitative real-time PCR analysis further revealed that the transcriptional interaction among these genes.Our data thus provide no vel evidence for Hox gene regulati on of in sect embry onic patterning.