Simcox A, Mitra S, Truesdell S, Paul L, Chen T, Butchar JP, Justiniano S. Efficient genetic method for establishing Drosophila cell lines unlocks the potential to create lines of specific genotypes.
PLoS Genet 2008;
4:e1000142. [PMID:
18670627 PMCID:
PMC2474701 DOI:
10.1371/journal.pgen.1000142]
[Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Accepted: 06/24/2008] [Indexed: 12/22/2022] Open
Abstract
Analysis of cells in culture has made substantial contributions to biological research. The versatility and scale of in vitro manipulation and new applications such as high-throughput gene silencing screens ensure the continued importance of cell-culture studies. In comparison to mammalian systems, Drosophila cell culture is underdeveloped, primarily because there is no general genetic method for deriving new cell lines. Here we found expression of the conserved oncogene RasV12 (a constitutively activated form of Ras) profoundly influences the development of primary cultures derived from embryos. The cultures become confluent in about three weeks and can be passaged with great success. The lines have undergone more than 90 population doublings and therefore constitute continuous cell lines. Most lines are composed of spindle-shaped cells of mesodermal type. We tested the use of the method for deriving Drosophila cell lines of a specific genotype by establishing cultures from embryos in which the warts (wts) tumor suppressor gene was targeted. We successfully created several cell lines and found that these differ from controls because they are primarily polyploid. This phenotype likely reflects the known role for the mammalian wts counterparts in the tetraploidy checkpoint. We conclude that expression of RasV12 is a powerful genetic mechanism to promote proliferation in Drosophila primary culture cells and serves as an efficient means to generate continuous cell lines of a given genotype.
In Drosophila, the genetic analysis of whole animals has been the focus of the field and has been exceptionally successful. Gene discoveries in flies have led to parallel studies in vertebrates and hence have accelerated the understanding of biology. Furthermore, some 60–70% of human disease genes are conserved in Drosophila, thus making the genetically tractable fly a useful disease model. While the whole-organism approach in Drosophila is powerful, there are studies that can best be conducted in cell lines. In this regard, Drosophila lags far behind mammalian systems, in which creation of cell lines using genetic manipulation is routine. We sought to test whether similar genetic approaches could be used in Drosophila. We discovered a simple genetic method for the rapid production of fly cell lines using an activated oncogene to stimulate proliferation in cultured embryonic cells. The method has immediate application for creating custom cell lines of a given genotype. We provided an example of this by making lines in which a tumor suppressor gene is targeted. Specifically designed cell lines will be extremely valuable for gene discovery using whole-genome RNAi screens and for producing large numbers of cells of a specific genotype for biochemical studies.
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