Table 3.

Reference genes are listed from most to least stable, according to geNorm analysis, in zebra finch and white-throated sparrow brain, pituitary, ovary, and testis. The average expression stability value (M) is listed next to each gene.^a

	Zebra finch		White-throated Sparrow
Tissue	Gene	M	Gene	M
Brain	GAPDH	0.108	RPL4	0.276
	PPIA	0.108	PPIA	0.276
	RPL4	0.127	TFRC	0.403
	RPL32	0.133	HPRT	0.488
	ACTB	0.145	GAPDH	0.567
	HPRT	0.156	RPL32	0.612
	18S	0.180	18S	0.666
	TFRC	0.201
	UBC	0.237
Pituitary	RPL4	0.124	18S	0.347
	RPL32	0.124	GAPDH	0.347
	PPIA	0.177	HPRT	0.387
	GAPDH	0.208	ACTB	0.485
	18S	0.233	HMBS	0.621
	HPRT	0.253
	ACTB	0.297
	UBC	0.347
	TFRC	0.392
Ovary	ACTB	0.115	HMBS	0.266
	PPIA	0.115	HPRT	0.266
	RPL4	0.197	GAPDH	0.288
	RPL32	0.225	PPIA	0.311
	GAPDH	0.253	RPL4	0.327
	UBC	0.301	RPL32	0.364
	18S	0.340	ACTB	0.402
	HPRT	0.402	TFRC	0.455
	TFRC	0.479	18S	0.571
Testis	RPL4	0.235	HPRT	0.279
	RPL32	0.235	PPIA	0.279
	PPIA	0.242	RPL4	0.305
	ACTB	0.257	RPL32	0.340
	HPRT	0.287	ACTB	0.384
	TFRC	0.362	GAPDH	0.434
	18S	0.446	TFRC	0.464
	UBC	0.544	HMBS	0.602
	GAPDH	0.609	18S	0.753

^aBecause gene ratios are used for stability measurements, the two most stable genes cannot be ranked in order.