Cytoplasmic Compartmentalization of the Fetal piRNA Pathway in Mice
Figure 5
The effect of Mael deficiency on piRNA expression in gonocytes.
(A) Annotation of small RNAs cloned from testes of wild-type and Mael-mutant animals. The right panel shows the ratio of LINE and LTR piRNA to miRNA. (B) The size range of piRNAs in the mael mutant. Total cellular piRNA populations are composed of two complexes, MILI, with average piRNA length 26 nt. and MIWI2 with average piRNA length 28 nt. The length profile reflects the ratio of both complexes in the cell. In wild-type animals the ratio of does not significantly change between E16.5 and P2. MIWI2-associated piRNAs (28 nt) corresponding to both LINE and LTR retrotransposons are significantly reduced in Mael-mutant animals. (C) The ratio of sense to antisense piRNAs for L1 and IAP retrotransposons. The amount of LINE L1 antisense piRNA is reduced in Mael-deficient animals at P2. In contrast, amount of LTR IAP antisense piRNA remains stable. (D) The ratio of secondary to primary piRNAs for L1 and IAP retrotransposons. The amount of secondary piRNAs that correspond to LINE L1 and LTR IAP is reduced in Mael-deficient animals at P2.