Characteristics of SGR- and retrotransposon-derived sRNAs. The length and 3′-end nucleotide distribution of (A) SGR-derived sRNAs and (B) retrotransposon-derived sRNAs. (C) Northern blot analysis of SGR- and retrotransposon-derived sRNAs. (D) The composition of retrotransposon-derived sRNAs in four sRNA libraries. (E) The sRNA distribution pattern of GilT, GilM, and GilD. Trop refers to trophozoite. E3h, E6h, E12h, E24h, and E48h refer to encystation 3, 6, 12, 24, and 48 h, respectively. SGR-sRNAs and RT-sRNAs refer to SGR-derived sRNAs and retrotransposon-derived sRNAs, respectively. RT, retrotransposon.