Xu/Silies
Evolution and genetic regulation of fecundity in the Colorado Potato Beetle
Supervisor: Shuqing Xu
Co-Supervisor: Marion Silies
Scientific Background
Rapid increase in fecundity is one of major traits associated with the evolution of agricultural pests. Insect fecundity is strongly affected by the ovariole number, which is genetically controlled, but can be influenced by environmental factors, such as temperature and food quality.
In Drosophila, evolutionary changes in ovariole number are associated with the number of terminal filament cells (TFCs) in the terminal filament (TF), a stack of 9-10 disc-shaped cells located at the anterior tip of each ovariole. The regulation of both TFC and TF numbers is dependent on the Hippo signalling pathway, an evolutionarily conserved regulator of organ growth and cell fate that also regulates haematopoiesis in Drosophila. However, the genetic mechanism underlying the increased ovariole number in agricultural pests remains unclear.
Project description
To identify the genetic mechanisms underlying ovariole number variations in CPB, we will perform quantitative trait loci (QTL) analysis using the established mapping populations. We will also compare the small RNA profiles and single-cell transcriptomes of the TF between the two genotypes that differ in their ovariole numbers. The outcomes will provide new insights into the cellular regulation of cell fate, e.g., via small RNAs, involved in controlling ovariole numbers in CPB. Furthermore, we will use the population genomics approach to characterize the signature of selection in CPB and investigate whether the evolution of the toxin and ovariole number in CPB was under natural selection.
What you will learn
You will learn state-of-the-art genetic and genomic tools. In addition, you will also develop critical thinking, project and time management skills.
Your qualifications
You should have work experience in statistics, evolutionary genetics/genomics. Knowledge in insect physiology and developmental biology is a plus.
Publications relevant to this project
Sarikaya DP, Church SH, Lagomarsino LP, Magnacca KN, Montgomery SL, Price DK, Kaneshiro KY, Extavour CG (2019) Reproductive capacity evolves in response to ecology through common changes in cell number in Hawaiian Drosophila. Curr Biol. 29(11):1877-1884.e6. doi.org/10.1016/j.cub.2019.04.063
Sarikaya DP, Extavour CG (2015) The Hippo pathway regulates homeostatic growth of stem cell niche precursors in the Drosophila ovary. PLoS Genet 11: e1004962. doi.org/10.1371/journal.pgen.1004962
Edison A, Michelbach A, Sowade D, Kertzel H, Schmidt L, Schäfer M, Hackhausen M, Nauen R, Duchen P, Xu S (2024) Evidence of active oviposition avoidance to systemically applied imidacloprid in the Colorado potato beetle. Insect Sci. doi.org/10.1111/1744-7917.13319