ABSTRACT
First member of Ets gene family was discovered a decade ago by studying avian erythroblastosis virus, E26. This virus encodes a tripartite protein gag-myb-ets with a molecular weight of 135 kDa. Subsequently, a series of cellular Ets genes were isolated (Ets-1, Ets-2, Erg, Elk-1, Sap-1, PEA-3, PU.1, Fli-1, Pok/Yan, Etv-1 etc.). These genes share sequence homology to E26 Ets gene (v-ets or viral ets). Ets genes are highly conserved in phylogenetically divergent species from Drosophila to man. Mammalian Ets genes are located on different chromosomes. Ets gene products are transcriptionally active sequence-specific DNA binding proteins and are differentially regulated. Ets genes are involved in certain chromosomal translocations leading to the formation of chimeric fusion proteins that are associated with certain leukemias and soft tissue cancers. Ets genes also have a role in T-cell development and molecular and genetic analysis of Down Syndrome patients have implicated the human Ets-2 and Erg genes in the disease. Down Syndrome afflicted patients have immunologic and thymic disorders as well as a greater risk for leukemic disease. Thus, Ets genes having homology to viral oncogenes, may be instrumental in regulating cellular growth and differentiation, as well as organismal development. Alteration of these genes and their products may cause deregulation of normal cell growth and differentiation and result in a disease.