TABLE 2.

Reactivity of Clones with Anti-ventricular and/or Anti-embryonic MHC mAbs

Source of cells	Culture age (days)	Number of clones		Total MHC⁺ clones
Source of cells	Culture age (days)	E⁺V⁺	V⁺	Total MHC⁺ clones
E14	5	43	9	52
	10	57	0	57
	15	50	0	50
E18	7	22	11	33
	10	37	5	42
	15	50	0	50
1-day	8	0	5	5
	11	8	19	27
	15	15	12	27
3-week	7	0	14	14
	11	0	16	16
	15	3	19	22

Note. Cells were plated at a clonal density and myogenic clones were marked prior to fixation and staining. Three (E18, 1-day, and 3-week) or four (E14) cultures were fixed for each time point and double-labeled as under Methods, except that nuclei were not counterstained. For cultures from E18, 1-day, and 3-week chicks the total numbers of clones screened for the first time point were 45, 26, and 22, respectively, but only myogenic clones (with MHC⁺ cells or myotubes) are shown. E⁺V⁺, clones with myocytes and myotubes reactive with both HV11 and EB165 mAbs. V⁺, clones with myocytes and myotubes reactive with HV11 mAb.