Table 6. Ranking of candidate reference genes in order of expression stability calculated by BestKeeper for different developmental stages.

Data shown as Pearson correlation coefficient (r) and standard deviation (SD).

Rank position	All stages		Stage 1		Stage 2		Stage 3		Stage 4		Stage 5
	SD	r	SD	r	SD	r	SD	r	SD	r	SD	r
1	HH3	RL28	RL28	PPIA	NDUFA7	RL5	TUBB	RL28	RS25	TUBB	RS25	GAPDH
2	GAPDH	RL5	COX1	RL28	PPIA	RL28	RS25	NDUFA7	NDUFA7	COX1	PPIA	EF-1α
3	NDUFA7	RS25	HH3	RS25	HH3	RS8	UBE2	RL5	TUBB	EF-1α	UBE2	RL5
4	EF-1α	RS8	RL5	UBE2	GAPDH	COX1	RL28	COX1	UBE2	PPIA	RL28	RL28
5	PPIA	COX1	EF-1α	RS8	UBE2	TUBB	COX1	RS8	RS8	ACT	HH3	RS25
6	COX1	UBE2	UBE2	TUBB	EF-1α	GAPDH	RS8	RS25	PPIA	NDUFA7	TUBB	COX1
7	RL5	NDUFA7	RS25	EF-1α	RL28	EF-1α	NDUFA7	UBE2	RL28	RL28	COX1	NDUFA7
8	RL28	ACT	NDUFA7	NDUFA7	COX1	NDUFA7	HH3	ACT	RL5	UBE2	RL5	ACT
9	UBE2	PPIA	ACT	RL5	RS25	ACT	EF-1α	EF-1α	HH3	RL5	RS8	UBE2
10	RS25	EF-1α	PPIA	GAPDH	RL5	UBE2	RL5	PPIA	COX1	RS25	NDUFA7	HH3
11	ACT	TUBB	RS8	COX1	ACT	RS25	GAPDH	HH3	ACT	GAPDH	GAPDH	TUBB
12	RS8	GAPDH	GAPDH	ACT	RS8	PPIA	ACT	TUBB	EF-1α	HH3	ACT	PPIA
13	TUBB	HH3	TUBB	HH3	TUBB	HH3	PPIA	GAPDH	GAPDH	RS8	EF-1α	RS8