Shaikh Umayr, Sherlock Kathleen, Wilson Julia, Gilliland William, Lewellyn Lindsay
bioRxiv. 2024 Jul 16:2023.08.18.553876. doi: 10.1101/2023.08.18.553876.
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 egg chamber is a powerful model in which to study the relative growth rates of subcellular structures. The egg chamber contains a cluster of sixteen 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 different strategies could be used to alter final egg size.
Using the fruit fly egg chamber as a model, this study demonstrates that the size and scaling of germline intercellular bridges vary based on lineage.
亚细胞结构的大小必须受到严格控制以维持正常细胞功能。尽管其很重要，但很少有研究确定在细胞生长、分裂和重排的发育过程中细胞器或其他结构的大小是如何维持的。发育中的卵室是研究亚细胞结构相对生长速率的一个有力模型。卵室包含一组16个生殖系细胞，它们通过称为环管的细胞间桥相连。随着卵室的生长，生殖系细胞和连接它们的环管会增大。在这里，我们证明环管大小的缩放与谱系有关；最大的“初生”环管大小增加的速率相对慢于源自后续有丝分裂的环管。即使定向运输减少、环管大小改变或在生殖系细胞数量加倍的卵室中，这种基于谱系的缩放关系仍会维持。对产生更大或更小成熟卵的品系的分析表明，可以使用不同策略来改变最终卵的大小。
本研究以果蝇卵室为模型，证明生殖系细胞间桥的大小和缩放因谱系而异。
