Fig. 2

3’UTRs are the shortest in spermatids. a Schematic showing analysis of 3’UTR-APA using RNA-seq reads. Three 3’UTR-APA isoforms are shown. The common 3’UTR portion is called cUTR, and the alternative portion aUTR. RNA-seq reads mapped to aUTR was normalized to those mapped to cUTR to infer the relative expression of long vs. short 3’UTR isoforms. b Cumulative distribution function (CDF) curves of log2Ratio for RNA-seq reads mapped to aUTRs vs. those to cUTRs in different purified cells from testis. Median values are shown on the right. The data set used [NCBI GEO:GSE43717] was based on a strand-specific RNA-seq method. c An example gene Cep57. The 3’READS data indicating 3’UTR-pA sites are shown on the top and RNA-seq data are shown at the bottom. Weighted mean of 3’UTR size based on the 3’READS data is shown for each time point