ABSTRACT
The zebrafish has emerged as a powerful genetic model of cancer, but has been limited by the use of stable transgenic approaches to induce disease. Here, a co-injection strategy is described that capitalizes on both the numbers of embryos that can be microinjected and the ability of transgenes to segregate together and exert synergistic effects in forming tumors. Using this mosaic transgenic approach, gene pathways involved in tumor initiation and radiation sensitivity have been identified.
Subject(s)
Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/radiation effects , Gene Transfer Techniques , Microinjections/methods , Neoplasms, Radiation-Induced/genetics , Animals , Animals, Genetically Modified , Cleavage Stage, Ovum , DNA-Binding Proteins/administration & dosage , DNA-Binding Proteins/genetics , Embryo, Nonmammalian , Genes, bcl-2 , Genes, myc , Genes, p53 , Green Fluorescent Proteins/administration & dosage , Green Fluorescent Proteins/genetics , Luminescent Proteins/administration & dosage , Luminescent Proteins/genetics , Mutant Proteins/genetics , Nuclear Proteins/administration & dosage , Nuclear Proteins/genetics , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins p21(ras) , Transgenes , Zebrafish/embryology , ras Proteins/genetics , Red Fluorescent ProteinABSTRACT
The synthetic multivulva (synMuv) genes define two functionally redundant pathways that antagonize RTK/Ras signaling during Caenorhabditis elegans vulval induction. The synMuv gene lin-35 encodes a protein similar to the mammalian tumor suppressor pRB and has been proposed to act as a transcriptional repressor. Studies using mammalian cells have shown that pRB can prevent cell cycle progression by inhibiting DP/E2F-mediated transcriptional activation. We identified C. elegans genes that encode proteins similar to DP or E2F. Loss-of-function mutations in two of these genes, dpl-1 DP and efl-1 E2F, caused the same vulval abnormalities as do lin-35 Rb loss-of-function mutations. We propose that rather than being inhibited by lin-35 Rb, dpl-1 DP and efl-1 E2F act with lin-35 Rb in transcriptional repression to antagonize RTK/Ras signaling during vulval development.