Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA.
Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA.
Development. 2024 Aug 15;151(16). doi: 10.1242/dev.202676. Epub 2024 Aug 27.
The size of subcellular structures must be tightly controlled to maintain normal cell function. Despite its importance, few studies have determined how the size of organelles or other structures is maintained during development, when cells are growing, dividing and rearranging. The developing Drosophila egg chamber is a powerful model in which to study the relative growth rates of subcellular structures. The egg chamber contains a cluster of 16 germline cells, which are connected through intercellular bridges called ring canals. As the egg chamber grows, the germline cells and the ring canals that connect them increase in size. Here, we demonstrate that ring canal size scaling is related to lineage; the largest, 'first-born' ring canals increase in size at a relatively slower rate than ring canals derived from subsequent mitotic divisions. This lineage-based scaling relationship is maintained even if directed transport is reduced, ring canal size is altered, or in egg chambers with twice as many germline cells. Analysis of lines that produce larger or smaller mature eggs reveals that different strategies could be used to alter final egg size.
细胞内结构的大小必须被严格控制，以维持正常的细胞功能。尽管这一点很重要，但很少有研究确定细胞器或其他结构的大小在细胞生长、分裂和重新排列的发育过程中是如何维持的。发育中的果蝇卵室是研究细胞内结构相对生长速度的有力模型。卵室包含一组 16 个生殖细胞，它们通过称为环道的细胞间桥连接。随着卵室的生长，生殖细胞和连接它们的环道的大小都在增加。在这里，我们证明环道大小的缩放与谱系有关；最大的“第一出生”环道的生长速度相对较慢，而源自随后有丝分裂分裂的环道则生长速度较快。即使减少定向运输、改变环道大小，或者在具有两倍数量的生殖细胞的卵室中，这种基于谱系的缩放关系也能保持。对产生更大或更小成熟卵子的谱系的分析表明，可以使用不同的策略来改变最终卵子的大小。
