Not all insulin-like peptides promote egg development in Aedes aegypti

Sunday, November 13, 2022

9:48 AM – 10:00 AM PT

Location: Vancouver Convention Centre, Meeting Room 111/112

Presenting Author(s)

MB

Mark R. Brown (he/him/his)

Professor
University of Georgia
Athens, Georgia

Co-Author(s)

KC

Kangkang Chen

University of Georgia
Athens, Georgia
XD

Xiaoyi Dou

University of Georgia
Athens, Georgia
MS

Michael R. Strand

Professor
University of Georgia
Athens, Georgia

Egg development in the mosquito A. aegypti is activated after a blood meal by the release of insulin-like peptides (ILPs) and ovary ecdysteroidogenic hormone (OEH) from brain neurosecretory cells (NSCs). We previously reported that ILP3 and OEH are so localized and active in bioassays and now have completed assessment of the other 7 ILPs. First the spatio-temporal expression patterns for the 8 ILPs, OEH, and their receptors were characterized in females before and after blood feeding. Then, the activity of purified ILPs and OEH, along with 20E, was compared in bioassays for egg development in females. Results indicated that ILPs and OEH expressed in NSCs are rapidly released in response to blood feeding. In vivo assays with blood fed females indicated that seven ILPs and OEH, but not ILP5, had similar activity in promoting egg development. In contrast, ex vivo assays with tissues from non-blood fed females indicated that only ILPs and OEH from NSCs strongly activated processes and signaling required for egg formation but required the presence of 20E.