Reversible response of protein localization and microtubule organization to nutrient stress during Drosophila early oogenesis |
| |
Authors: | Shimada Yuko Burn K Mahala Niwa Ryusuke Cooley Lynn |
| |
Institution: | aDepartment of Genetics, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA;bGraduate school of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan;cDepartment of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA;dInitiative for the Promotion of Young Scientists' Independent Research, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571, Japan;eDepartment of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Ave., New Haven, CT 05610, USA |
| |
Abstract: | The maturation of animal oocytes is highly sensitive to nutrient availability. During Drosophila oogenesis, a prominent metabolic checkpoint occurs at the onset of yolk uptake (vitellogenesis): under nutrient stress, egg chambers degenerate by apoptosis. To investigate additional responses to nutrient deprivation, we studied the intercellular transport of cytoplasmic components between nurse cells and the oocyte during previtellogenic stages. Using GFP protein-traps, we showed that Ypsilon Schachtel (Yps), a putative RNA binding protein, moved into the oocyte by both microtubule (MT)-dependent and -independent mechanisms, and was retained in the oocyte in a MT-dependent manner. These data suggest that oocyte enrichment is accomplished by a combination of MT-dependent polarized transport and MT-independent flow coupled with MT-dependent trapping within the oocyte. Under nutrient stress, Yps and other components of the oskar ribonucleoprotein complex accumulated in large processing bodies in nurse cells, accompanied by MT reorganization. This response was detected as early as 2 h after starvation, suggesting that young egg chambers rapidly respond to nutrient stress. Moreover, both Yps aggregation and MT reorganization were reversed with re-feeding of females or the addition of exogenous insulin to cultured egg chambers. Our results suggest that egg chambers rapidly mount a stress response by altering intercellular transport upon starvation. This response implies a mechanism for preserving young egg chambers so that egg production can rapidly resume when nutrient availability improves. |
| |
Keywords: | Drosophila oogenesis Polarized transport oskar RNP Starvation response Microtubule |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|