This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology (General Propeies, DNA Viruses), Subject name: Microbiology
Syncytium formation is the typical CPE produced by:- 
Select and explain. 
A. BK virus, B. JC virus, C. SV 40 virus, D. Measles virus
D: Measles virus
Answer: D: Measles virus 
Explanation: Syncytium formation is the typical CPE produced by Measles Virus. 1. Cytopathic effect (CPE): It is defined as the morphological change produced by the virus in the cell line detected by light microscope. 2. Types of Cytopathic Effects (CPE): Rapid crenation and degeneration of the entire cell sheet - Enteroviruses. Syncytium or multinucleated giant cell formation - Measles, RSV, HSV. Diffuse roundening and ballooning of the cell line - HSV. Cytoplasmic vacuolations - SV 40 (Simian vacuolating virus-40). Large granular clumps resembling bunches of grapes - Adenovirus. 3. Syncytia is formed by fusion of an infected cells with neighboring cells leading to the formation of multi-nucleated enlarged cells. This event is induced by surface expression of viral fusion protein that are fusogenic directly at the host cell membrane.