Trends in Parasitology 25(9), 432-9 Reporter genes facilitating discovery of drugs targeting protozoan parasites Anuradha Dube*, Reema Gupta and Nasib Singh Division of Parasitology, Central Drug Research Institute, Lucknow- 226 001, India * To whom correspondence should be addressed Dr (Mrs) Anuradha Dube Division of Parasitology, Central Drug Research Institute Post Box No. 173, Lucknow-226 001 (India) Tel: +91- 0522-2612411-18 Ext. 4398; Fax: +91-0522-2623938/2623405 E-mail: anuradha_dube@hotmail.com ; anuradha_dube@rediffmail.com Abstract Transfection of protozoan parasites, such as Plasmodium, Leishmania, Trypanosoma and Toxoplasma, with various reporter gene constructs, has revolutionized studies to understand the biology of the host–parasite interactions at the cellular level. It has provided impetus to the development of rapid and reliable drug screens for both established drugs and new molecules against different parasites and other pathogens. Furthermore, reporter genes have proved to be an excellent and promising tool for studying disease progression including imaging. Here, we review the recent advances made by using reporter genes for in-vitro and in-vivo drug screening, high-throughput screening, whole-animal non-invasive imaging for parasites and for the study of several aspects of host–parasite interactions.