Molecular characterization of the Krüppel-homolog 1 and its role in ovarian development in Sogatella furcifera (Hemiptera: Delphacidae)

Juvenile hormone (JH) plays a pivotal role in insect reproduction. The Kruppel-homolog 1 (Kr-h1) is a JH-inducible zinc finger transcription factor that has also been found to play a role in insect reproduction, however, its function varies across species. In this study, we cloned SfKr-h1 from Sogatella furcifera and investigated its role in ovarian development. The open reading frame of SfKr-h1 is 1 800 bp encoding 599 amino acids. The putative amino acid sequence of SfKr-h1 contains eight putative C2H2-type zinc finger domains and is highly homologous with the Kr-h1s of other hemipteran species. Expression of SfKr-h1 peaked 96 h after adult emergence and was highest in the ovary. RNA interference (RNAi) knockdown of SfKr-h1 substantially reduced the transcription of SfVg, and arrested ovarian development. These results suggest that SfKr-h1 is critical for normal ovarian development in S. furcifera.