Homeodomain proteins POU‐M2, antennapedia and abdominal‐B are involved in regulation of the segment‐specific expression of the clip‐domain serine protease gene CLIP13 in the silkworm, Bombyx mori. (16th April 2021)

• Record Type: Journal Article
• Authors: Liu, Huawei; Heng, Jingya; Wang, Luoling; Li, Youshan; Tang, Xin; Huang, Xuan; Xia, Qingyou; Zhao, Ping
• Is Part Of: Insect science. Volume 29:Number 1(2022)
• Page Start: 111
• Page End: 127
• Publication Date: 2021-04-16
• Subjects: Bombyx mori -- clip‐domain serine protease -- epidermis -- homeotic gene -- POU‐M2 -- 20‐hydroxyecdysone -- Bombyx mori; Insects -- Periodicals; Entomology -- Periodicals; 595.705
• DOI: 10.1111/1744-7917.12916
• Languages: English
• ISSNs: 1672-9609

Abstract

Abstract: Clip‐domain serine proteases (CLIPs) play important roles in insect innate immunity and development. Our previous studies indicated that CLIP13, an epidermis‐specific gene, was involved in cuticle remodeling during molting and metamorphosis in the silkworm, Bombyx mori . However, the transcriptional regulatory mechanism and regulatory pathways of CLIP13 remained unclear. In the present study, we investigated CLIP13 expression and the regulation pathway controlled by 20‐hydroxyecdysone (20E) in the silkworm. At the transcriptional level, expression of CLIP13 exhibited pronounced spatial and temporal specificity in different regions of the epidermis; homeodomain transcription factors POU‐M2, antennapedia ( Antp ), and abdominal‐B ( Abd‐B ) showed similar expression change trends as CLIP13 in the head capsule, thorax, and abdomen, respectively. Furthermore, results of cell transfection assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation demonstrated that POU‐M2, Antp, and Abd‐B were involved in the transcriptional regulation of CLIP13 by directly binding to their cis ‐response elements in CLIP13 promoter. RNA interference‐mediated silencing of POU‐M2, Antp, and Abd‐B led to a decrease of CLIP13 expression in the head capsule, the epidermis of the 1st to 3rd thoracic segments and the 7th to 10th abdominal segments, respectively. Consistent with CLIP13, 20E treatment significantly upregulated expression of POU‐M2, Antp, and Abd‐B in the silkworm epidermis. Taken together, these data suggest that 20E positively regulates transcription of CLIP13 via homeodomain proteins POU‐M2, Antp, and Abd‐B in different regions of the silkworm epidermis during metamorphosis, thus affecting the molting process. Our findings provide new insight into the functions of homeodomain transcription factors in insect molting. Abstract : CLIP13, POU‐M2, Antp, and Abd‐B have spatial and temporal epidermal specificity POU‐M2, Antp, and Abd‐B expression were upregulated by 20E in silkworm epidermis POU‐M2, Antp, Abd‐B bind to CLIP13 promoter CREs to enhance CLIP13 transcription POU‐M2, Antp, Abd‐B regulate segment‐specific CLIP13 transcription in metamorphosis