A chromatin structure informed exploration of gene regulation in anopheles coluzzii

The Medical College of Wisconsin, Inc. received a $429,000 Project Grant award from the National Institute of Allergy and Infectious Diseases (NIAID) under the Allergy and Infectious Diseases Research program (CFDA 93.855), effective June 25, 2025, with completion targeted for May 31, 2027. This research grant funds a two-part investigation into chromatin structure and gene regulation in Anopheles coluzzii mosquitoes, a principal malaria vector species. The project delivers scientific outputs focused on mapping chromatin architecture during immune activation in mosquito hemocytes and identifying gene regulatory networks for the immune deficiency pathway through enhancer RNA modulation techniques.

The research addresses a critical public health need by advancing understanding of endogenous gene regulatory mechanisms in vector mosquitoes, with the objective of informing more effective and evolutionarily sustainable vector control strategies to reduce malaria transmission. The project's dual specific aims—characterizing fine- and coarse-grained chromatin architecture with and without immune stimulation, and developing enhanced approaches for detecting enhancer target genes—generate foundational knowledge applicable to strengthening genetically modified mosquito control methodologies and other vector management interventions. Performance of the work occurs in Wauwatosa, Wisconsin.

Abstract

In light of increased insecticide resistance, additional vector control tools are needed to slow malaria transmission. A greater understanding of endogenous gene regulatory networks would greatly contribute to evolutionary informed control strategies. The objective of this project is two-fold. First chromatin architecture will be examined at coarse- and fine-grained scales in hemocyte cells with and without immune stimulation. Second, we will dissect endogenous regulatory networks for immune deficiency (IMD) pathway genes and develop an approach for detection of enhancer direct target genes rooted in enhancer RNA (erna) silencing. The rationale is based on the observation that the dynamics of chromatin architecture are influenced by underlying chromosome structure, including inversions, as well as by cell perturbations and differences in gene regulation underlie many medically important phenotypes including the susceptibility to malaria parasites in vector mosquitoes. Further, the ability to easily screen for enhancer target genes will be instrumental in our understanding of endogenous gene regulation. Our two independent specific aims focus on understanding endogenous gene regulation in hemocytes cells through examination of chromatin structure and dissection of IMD regulatory networks; aim 1) map chromatin architecture during immune activation in mosquito hemocytes and aim 2) identify gene regulatory networks for IMD pathway genes by modulating erna function. This project is significant because little is known about endogenous gene regulation in mosquito hemocytes and prominent methods of vector control, like genetically modified mosquitos, could be significantly strengthened and made more evolutionary informed by a mechanistic understanding of gene regulation and gene regulatory networks. The proposed project is innovative because IT couples a high-resolution exploration of chromatin architecture with modulation of erna levels for dissection of gene regulatory networks central to the IMD pathway. These complementary, yet independent, ways to explore the function of non-coding regulatory elements will provide new avenues for evolutionary informed vector control pertinent to the control of mosquito borne disease.