Table 1.

Transcriptional regulation and oncogenicity of Qin constructs

RCAS construct	Transcriptional regulation*	Focus formation in vitro†	Tumorigenicity
			Incidence‡	Latent period, weeks
v-Qin	1.8	34	10/11	2–6
c-Qin	11.2	35	3/12	6–7
CV§	3.2	25	3/3	3–5
VC§	17.3	30	1/4	6–7
RCAS + v-Qin¶	ND	5.0  ×  105	ND	ND
v-Qin-VP16 + v-Qin¶	ND	4.4  ×  104	ND	ND

^*Relative luciferase activity expressed as percent of RCAS control. Data are from a representative experiment. 

^†Number of foci per 50 ng DNA transfected (constructs v-Qin, c-Qin, CV, and VC), and transforming titer of RCAS-v-Qin virus expressed in focus forming units/ml (constructs RCAS + v-Qin and v-Qin-VP16 + v-Qin). Data are from a representative experiment. 

^‡Birds with tumors over birds injected. 

^§Recombinants between v-qin and c-qin (see Fig. 1A) (2). 

^¶CEF were first transfected with RCAS or vQ-VP16-RCAS coding for viral envelope protein of subgroup A, and after 1 week they were challenged with v-Qin-RCAS virus of envelope subgroup B. ND, not determined.