Table 1 . Information of candidate genes.

Category	Flybase ID	Symbol	Gene name	Chra	CDs lengthb	Gene functions
piRNA genes	FBgn0004872	piwi	piwi	2L	2532	piRNA generation
	FBgn0000146	aub	aubergine	2L	2601	piRNA generation
	FBgn0250816	AGO3	Argonaute 3	3L	2604	piRNA generation
	FBgn0041164	armi	armitage	3L	3825	RNA helicase
	FBgn0003483	spn-E	spindle E	3R	4305	RNA helicase
	FBgn0002652	squ	squash	2L	726	Nuclease
	FBgn0261266	zuc	zucchini	2L	762	Nuclease
	FBgn0033686	Hen1	PIMET/DmHen1	2R	1176	piRNA methyltransferase
	FBgn0016034	mael	maelstrom	3L	1389	Nuage component
	FBgn0034098	krimp	krimper	2R	2241	Nuage component
	FBgn0262526	vas	vasa	2L	661	Nuage component
	FBgn0004400	rhi	rhino	2R	1257	HP1 paralog, heterochromatin binding
P-element–specific genes	FBgn0014870	Psi	P-element somatic inhibitor	2R	2394	P-element somatic inhibitor; mRNA splicing factor
	FBgn0004838	Hrb27C	Heterogeneous nuclear ribonucleoprotein at 27C	2L	1266	mRNA splicing factor
	FBgn0011774	Irbp	Inverted repeat-binding protein	3R	1897	Recombination repair protein
	FBgn0041627	Ku80	Ku80	2L	2100	Recombination repair protein

^achromosome

^blength of coding regions (bp)