SummaryDe novo assembly is a difficult issue for heterozygous diploid genomes. The advent of high-throughput short-read and long-read sequencing technologies provides both new challenges and potential solutions to the issue. Here, we present HaploMerger2 (HM2), an automated pipeline for rebuilding both haploid sub-assemblies from the polymorphic diploid genome assembly. It is designed to work on pre-existing diploid assemblies, which are typically created by using de novo assemblers. HM2 can process any diploid assemblies, but it is especially suitable for diploid assemblies with high heterozygosity (≥3%), which can be difficult for other tools. This pipeline also implements flexible and sensitive assembly error detection, a hierarchical scaffolding procedure and a reliable gap-closing method for haploid sub-assemblies. Using HM2, we demonstrate that two haploid sub-assemblies reconstructed from a real, highly-polymorphic diploid assembly show greatly improved continuity.Availability and ImplementationSource code, executables and the testing dataset are freely available at https://github.com/mapleforest/HaploMerger2/releases/.Supplementary information Supplementary data are available at Bioinformatics online.

3' UTRs play important roles in the gene regulation network via their influence on mRNA stability, translational efficiency, and subcellular localization. For a given gene, 3' UTRs of different lengths generated by alternative polyadenylation (APA) may result in functional differences in regulation. The mechanistic details of how length changes of 3' UTRs alter gene function remain unclear. By combining APA sequencing and polysome profiling, we observed that mRNA isoforms with shorter 3' UTRs were bound with more polysomes in six cell lines but not in NIH3T3 cells, suggesting that changing 3' UTRs to shorter isoforms may lead to a higher gene translational efficiency. By interfering with the expression of TNRC6A and analyzing AGO2-PAR-CLIP data, we revealed that the APA effect on translational efficiency was mainly regulated by miRNAs, and this regulation was cell cycle dependent. The discrepancy between NIH3T3 and other cell lines was due to contact inhibition of NIH3T3. Thus, the crosstalk between APA and miRNAs may be needed for the regulation of protein translational efficiency.