Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA.
Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA.
J Cell Biol. 2021 Jul 5;220(7). doi: 10.1083/jcb.202012101. Epub 2021 May 5.
Drosophila oocytes develop together with 15 sister germline nurse cells (NCs), which pass products to the oocyte through intercellular bridges. The NCs are completely eliminated during stages 12-14, but we discovered that at stage 10B, two specific NCs fuse with the oocyte and extrude their nuclei through a channel that opens in the anterior face of the oocyte. These nuclei extinguish in the ooplasm, leaving 2 enucleated and 13 nucleated NCs. At stage 11, the cell boundaries of the oocyte are mostly restored. Oocytes in egg chambers that fail to eliminate NC nuclei at stage 10B develop with abnormal morphology. These findings show that stage 10B NCs are distinguished by position and identity, and that NC elimination proceeds in two stages: first at stage 10B and later at stages 12-14.
果蝇卵母细胞与 15 个姐妹生殖细胞系（NC）一起发育，这些细胞通过细胞间桥将产物传递给卵母细胞。NC 在第 12-14 阶段完全被消除，但我们发现，在第 10B 阶段，两个特定的 NC 与卵母细胞融合，并通过在卵母细胞前表面打开的通道挤出它们的核。这些核在卵质中熄灭，留下 2 个无核和 13 个有核的 NC。在第 11 阶段，卵母细胞的细胞膜边界大部分恢复。在第 10B 阶段未能消除 NC 核的卵母细胞发育成异常形态。这些发现表明，第 10B 阶段的 NC 因其位置和身份而被区分开来，并且 NC 消除分两个阶段进行：首先在第 10B 阶段，然后在第 12-14 阶段。
