Loss‐of‐function analyses of the fragile X‐related and dopamine receptor genes by RNA interference in the cricket Gryllus bimaculatus

In order to explore a possibility that the cricket Gryllus bimaculatus would be a useful model to unveil molecular mechanisms of human diseases, we performed loss‐of‐function analyses of Gryllus genes homologous to human genes that are responsible for human disorders, fragile X mental retardation 1 ( fmr1 ) and Dopamine receptor ( DopR ). We cloned cDNAs of their Gryllus homologues, Gb ' fmr1, Gb ' DopRI , and Gb ' DopRII , and analyzed their functions with use of nymphal RNA interference (RNAi). For Gb ' fmr1 , three major phenotypes were observed: (1) abnormal wing postures, (2) abnormal calling song, and (3) loss of the circadian locomotor rhythm, while for Gb ' DopRI , defects of wing posture and morphology were found. These results indicate that the cricket has the potential to become a novel model system to explore human neuronal pathogenic mechanisms and to screen therapeutic drugs by RNAi. Developmental Dynamics 238:2025–2033, 2009. © 2009 Wiley‐Liss, Inc.