Buenzow D E, Holmgren R
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA.
Dev Biol. 1995 Aug;170(2):338-49. doi: 10.1006/dbio.1995.1219.
The development of the central nervous system is known to require lineage-specific factors that are expressed in neuroblasts and their descendants, as well as molecules involved in cell-cell signaling mechanisms. The transcription factors encoded by the gooseberry locus appear to be required for the proper specification of neuroblasts and their lineages. To examine whether gooseberry expression is lineage-specific, we have utilized the FLP recombinase of yeast to positively mark cell lineages throughout Drosophila development. In this system, the actin5C promoter and the lacZ gene are separated by a polyadenylation signal flanked by two direct repeat FRTs. A heat shock is used to induce a pulse of FLP recombinase which catalyzes a site-specific recombination event between the FRT sites. The resulting excision of the polyadenylation site allows expression of lacZ from the actin5C promoter. The descendants of a cell which has undergone a recombination event are now positively marked, enabling us to compare cell lineages with the pattern of gooseberry gene expression. We find that the expression of the gooseberry locus is lineage-specific, suggesting that gooseberry may function as a selector gene in the patterning of the Drosophila central nervous system.
已知中枢神经系统的发育需要在神经母细胞及其后代中表达的谱系特异性因子，以及参与细胞间信号传导机制的分子。醋栗基因座编码的转录因子似乎是神经母细胞及其谱系正确特化所必需的。为了研究醋栗的表达是否具有谱系特异性，我们利用酵母的FLP重组酶在果蝇发育过程中对细胞谱系进行正向标记。在这个系统中，肌动蛋白5C启动子和lacZ基因被一个两侧有两个直接重复FRT的聚腺苷酸化信号隔开。通过热休克诱导FLP重组酶脉冲，该酶催化FRT位点之间的位点特异性重组事件。聚腺苷酸化位点的切除使得lacZ能够从肌动蛋白5C启动子表达。经历了重组事件的细胞的后代现在被正向标记，这使我们能够将细胞谱系与醋栗基因表达模式进行比较。我们发现醋栗基因座的表达具有谱系特异性，这表明醋栗可能在果蝇中枢神经系统的模式形成中作为选择基因发挥作用。
