Class 3* Flashcards
First virus discovery
agent that causes tobacco mosaic disease
agent could pass through a filter that retained bacteria and could diffuse through agar gel
True or false
viruses are unicellular
False, viruses are acellular (they are not cells)
RNA viruses in DNA form
provirus
host cell is destroyed during infectious cycle
Virulent
host cell survives, viral genome remains in cell, still making progeny virus
temperate
Peyton Rous found a chicken virus associated with formation of ____. Named _____
Sarcoma, Rous sarcoma Virus
bone and soft tissue cancer
sarcoma
Cell Culture ____ methods were developed to study effects of viruses on cells
In vitro
Shown experimentally that all cells in a focus are the descendants of a single infected progenitor
Provided further evidence that tumors in humans may also arise from a single common progenitor cell that was somehow transformed (virus, chemical, physical)
clone
when RSV was added to cells in culture…
- Foci Appeared – cell growth
- Change in morpohology
- Loss of contact inhibition
- –>Cells had transformed from normal to tumor cell
Normal shape Contact inhibition Anchorage-dependent Mortal Needs external growth factors
normal cells
Altered morphology (rounded) Loss of Contact inhibition Anchorage-independent Immortal Reduced need for growth factors
Tumorigenicity?
Transformed cells
Cells grown in semi-solid medium so they are prevented from attaching to dish
Anchorage-independent growth
Good-ish prediction of ability of cells to form tumors in vitro
tumorigenicity
T/F
Only DNA viruses can promote tumor formation
False, RNA and DNA
