Characterizing the relative abundance of circadian transcription factors in diapausing and nondiapausing Northern house mosquitoes

• Published in: Journal of insect physiology 2022-07, Vol.140, p.104404-104404, Article 104404
• Main Authors: Peffers, Caitlin, Meuti, Megan E.
• Format: Article
• Language: English
• Subjects: Clock proteins; Culex pipiens; Cycle (CYC); Par Domain Protein1 (PDP1); seasonal responses; Western blotting
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/j.jinsphys.2022.104404

[Display omitted] •CYC and PDP1 are circadian transcription factors that may regulate seasonal responses.•CYC and PDP1 protein levels do not change in the whole bodies of Culex pipiens.•CYC levels cycle in the heads of non-diapausing Cx. pipiens but not in diapausing mosquitoes.•PDP1 levels oscillate in heads of both non-diapausing and diapausing mosquitoes. The Northern house mosquito (Culex pipiens) is a major vector of West Nile virus. To survive harsh conditions in winter adult females of Cx. pipiens enter a state of arrested reproductive development called diapause. Diapause is triggered by the short daylengths of late summer and early fall. The methods by which Cx. pipiens measures daylength are still unknown. However, it is suspected that clock genes, which provide information on daylength, may also regulate diapause. The proteins produced by these genes often cycle in abundance throughout the day in diapausing and nondiapausing insects. Two clock genes suspected to control diapause are cycle (cyc) and Par domain protein1 (Pdp1) as they encode circadian transcription factors that may regulate genes that are involved in diapause. Using Western blotting we measured the relative protein abundance of CYC and PDP1 throughout the day in the whole bodies and the heads of Cx. pipiens reared under either long-day, diapause-averting conditions or short-day, diapause-inducing conditions. We found that in whole bodies there was no significant oscillation of CYC or PDP1 abundance in both long day and short day-reared mosquitoes. In the heads of long day-reared mosquitoes both CYC and PDP1 cycled. In contrast, only PDP1 abundance showed diel differences in abundance in the heads of short day-reared mosquitoes. These data bring us one step closer to understanding the role that CYC and PDP1 may play in regulating diapause and other biological processes.