Table 1.

Results of the simulations of 1,000 crosses between parents differing for the distribution of concentrations of four glycolytic enzymes

Inheritance		Heterosis			R 2				H > 0 and ∑e add < 0		H > 0 and I < 1
PFK	FBA	No	Mid-parent	Best-parent	∑a	∑d	∑e dom	∑e add	Nb	%	Nb	%
1	0.5	0	488	512	0.24	0.25	0.22	0.7	501	97	447	87
0.8	0.5	0	527	473	0.27	0.2	0.19	0.72	469	99	423	89
0.5	0.5	0	600	400	0.35	0.12	0.13	0.75	398	99	371	93
0.2	0.5	209	516	275	0.51	0.06	0.05	0.66	275	100	266	97
0	0.5	502	372	126	0.57	0.26	0.1	0.31	126	99	126	100
0.5	1	0	376	624	0.09	0.36	0.36	0.73	578	92	508	81
0.5	0.8	0	456	544	0.16	0.26	0.28	0.77	527	97	467	86
0.5	0.5	0	600	400	0.35	0.12	0.13	0.75	398	99	371	93
0.5	0.2	378	396	226	0.55	0.15	0.05	0.47	225	99	218	96
0.5	0	599	305	96	0.55	0.36	0.11	0.21	96	99	96	100
1	1	0	253	747	0.04	0.48	0.5	0.66	618	83	542	73
1	0	510	324	166	0.46	0.41	0.15	0.19	165	99	165	99
0	1	335	410	255	0.35	0.36	0.19	0.28	255	100	255	100
0	0	892	108	0	0.74	0.34	0.03	0.17	0	–	0	–

Columns “Inheritance”: coefficients of inheritance for enzymes PFK and FBA. Columns “Heterosis”: observed numbers of each type of inheritance. Columns R ²: fraction of explained variance in the regression of H to the sums of the different genetic effects. Last columns: numbers and percentages of cases where best-parent heterosis corresponded to a negative value of the sum of additive-by-additive epistasis effects (∑e _add), or where best-parent heterosis corresponded to a value of the epistasis index I lower than unity