Fig. 4. XNIF-LE mediates accumulation in the mitochondrial cloud. lacZ-tagged RNAs were injected into stage I-III oocytes and localization was visualized by whole-mount in-situ hybridization. Localization to the vegetal cortex in stage III and enrichment in the mitochondrial cloud in stage I was observed with the transcript nt 252-551 (A,F). The transcript nt 252-381 does not accumulate in the mitochondrial cloud, but is transported in stage III oocytes (B,G). A transcript containing nucleotides 415-551 neither localizes in stage I nor in stage III oocytes (C,H). A transcript containing a duplication of nucleotides 252-381 in tandem repeat localizes to the mitochondrial cloud in stage I and to the vegetal cortex in stage II-III oocytes (D,I). No localization to the mitochondrial cloud or vegetal cortex was observed with a transcript containing the XNIF 3'-UTR (E,J). Scale bar: 100 µm in A-D; 500 µm in F-J. (K) The nucleotide sequence of the nt 252-551 localization element is shown. CAC-sequence element containing motifs and isolated CAC triplets are shaded. The nt 252-381 minimal sequence that mediates localization in stage III oocytes is boxed.