Many experimental approaches rely on controlling gene expression in select subsets of cells within an individual animal. However, reproducibly targeting transgene expression to specific fractions of a genetically defined cell type is challenging. We developed Sparse Predictive Activity through Recombinase Competition (SPARC), a generalizable toolkit that can express any effector in precise proportions of post-mitotic cells in Drosophila. Using this approach, we demonstrate targeted expression of many effectors in several cell types and apply these tools to calcium imaging of individual neurons and optogenetic manipulation of sparse cell populations in vivo.

许多实验方法依赖于控制个体动物内选定细胞子集中的基因表达。然而，将转基因表达可再现地靶向遗传定义的细胞类型的特定部分是具有挑战性的。我们通过重组酶竞争（SPARC）开发了稀疏的预测活性，SPARC是一种可推广的工具包，可以在果蝇中以精确比例表达有丝分裂后细胞中的任何效应子。使用这种方法，我们证明了多种细胞类型中许多效应子的靶向表达，并将这些工具应用于单个神经元的钙成像以及体内稀疏细胞群体的光遗传学操作。