TABLE 2.

Mapping crosses and tail phenotypes at birth

	spretus cross
	Chr 17	Chr 6		Chr 17	Chr 6
P	+Ttint/+Ttint	int/int	×	+Tsp +Tsp/+Tsp +Tsp	sp/sp
F1	+Ttint/+Tsp +Tsp	int/sp	×	T/+Tsp +Tsp	BT/BT
	Progeny		Phenotype	Expected (%)	Observed no.	Observed (%)
Test cross	+Ttint/+TBT	sp/BT	Normal tail
	+TBT/+Tsp +Tsp	sp/BT	Normal tail
	+Ttint/+TBT	int/BT	Normal tail	62.5	478	67
	+TBT/+Tsp +Tsp	int/BT	Normal tail
	T/+Tsp +Tsp	sp/BT	Normal tail
	T/+Tsp +Tsp	int/BT	Short tail
				25	148	21
	T/+Ttint	sp/BT	Short tail
	T/+Ttint	int/BT	Tailless	12.5	87	12
			Total	100	713	100
	castaneus cross
	Chr 17	Chr 6		Chr 17	Chr 6
P	+Ttint/+Ttint	int/int	×	+Tcas/+Tcas	cas/cas
F1	+Ttint/+Tcas	int/cas	×	T/+TBT	BT/BT
	Progeny		Phenotype	Expected (%)	Observed no.	Observed (%)
Test cross	+Ttint/+TBT	cas/BT	Normal tail
	+TBT/+Tcas	cas/BT	Normal tail	50	269	51.7
	+Ttint/+TBT	int/BT	Normal tail
	+TBT/+Tcas	int/BT	Normal tail
	T/+Tcas	cas/BT	Short tail
				25	136	26.2
	T/+Ttint	cas/BT	Short tail
	T/+Tcas	int/BT	Tailless
				25	115	22.1
	T/+Ttint	int/BT	Tailless
			Total	100	520	100

Gene symbols: +^Ttint, wild type of T from the tint strain; +^Tsp, wild type of T from spretus (for clarity, we assume it is duplicated); +^TBT, wild type of T from BTBRTF; +^Tcas, wild type of T from castaneous; T, the original Bracyhury deletion. The chromosome 6 column refers to the tint locus, mutant “int,” wild type from spretus “spret,” from castaneous “cast,” or from BTBRTF “BT.”