Which came first? The variation in egg cell formation between the model fruit fly and the paper wasp

Cellular characteristics of the formation and maturation of an egg cell, known as oogenesis, have been studied extensively in the fruit fly, Drosophila melanogaster. Insects show different types of oogenesis, but the fruit fly exhibits polytrophic meroistic oogenesis. During this process, the egg cell goes through multiple rounds of division to produce nurse cells that remain connected through actin filaments. These nurse cells do not mature into eggs and remain to support the growth of the oocyte. Many other insects, including eusocial insects, also exhibit this type of oogenesis. Despite having similar processes of oogenesis, the ovary morphology between species can vary extensively to accommodate different needs. For example, honeybee queens have large ovaries to facilitate the continuous production of thousands of offspring.In contrast, primitively eusocial paper wasps, Polistes exclamans, have queens that maintain smaller ovaries due to their small colony sizes. In this project, immunostaining techniques were used to visualize cellular structures that are important for oogenesis in both D. melanogaster and P. exclamans. Results revealed variations in multiple areas of oogenesis involving microtubule formation, germ cell organization, and actin filament formation between the two species. This project provides insight into how processes such as oogenesis differ at a cellular level between insects despite undergoing similar processes for egg cell development. Implications for how earlier processes in oogenesis may adapt with eusociality are discussed.