View Program - 63rd Annual Drosophila Research Conference

The size of intracellular structures must be tightly controlled in order to maintain normal cell function. This is especially important when cells are part of growing tissues or organs. However, despite its importance, few studies have analyzed how the size of organelles or other structures changes during development. The developing egg chamber provides a unique model in which to study the relative growth rates of multiple structures. The egg chamber is composed of a cluster of germ cells (an oocyte and 15 supporting nurse cells) surrounded by a layer of somatic epithelial cells. In addition to the growth of the overall egg chamber, it is also known that multiple structures within the egg chamber grow as well. For example, the nurse cells, their nuclei, and nucleoli increase in size as the egg chamber develops, and the intercellular bridges, or ring canals, that connect the germ cells also significantly increase in diameter. Here, we are able to take advantage of differences in egg size both within D. melanogaster and between Drosophila species (D. pseudoobscura, D. melanogaster, D. santomea, D. yakuba, and D. virilis) to test whether the relative rates of growth of the germline ring canals and nurse cell nuclei are consistent in developing egg chambers of different sizes. To determine whether these growth rates are impacted by the location of the structure within the egg chamber, we specifically focus on two sets of nurse cells and their associated structures – the nurse cells directly connected to the oocyte and those located at the anterior of the egg chamber. In addition, we test whether altering oocyte growth impacts the growth of the germline ring canals or nurse cell nuclei. In the future, we hope to determine how these scaling relationships are maintained during dramatic tissue growth and to test whether the same scaling relationships are observed in more distantly related species.

Nuclear and ring canal growth in the germline of the developing egg chamber