Linkage maps enable the study of important biological questions. The construction of high-density linkage maps appears more feasible since the advent of next-generation sequencing (NGS), which eases SNP discovery and high-throughput genotyping of large population. However, the marker number explosion and genotyping errors from NGS data challenge the computational efficiency and linkage map quality of linkage study methods. Here we report the HighMap method for constructing high-density linkage maps from NGS data. HighMap employs an iterative ordering and error correction strategy based on a k-nearest neighbor algorithm and a Monte Carlo multipoint maximum likelihood algorithm. Simulation study shows HighMap can create a linkage map with three times as many markers as ordering-only methods while offering more accurate marker orders and stable genetic distances. Using HighMap, we constructed a common carp linkage map with 10,004 markers. The singleton rate was less than one-ninth of that generated by JoinMap4.1. Its total map distance was 5,908 cM, consistent with reports on low-density maps. HighMap is an efficient method for constructing high-density, high-quality linkage maps from high-throughput population NGS data. It will facilitate genome assembling, comparative genomic analysis, and QTL studies. HighMap is available at http://highmap.biomarker.com.cn/.

Drosophila melanogaster Tango1 is required for secretion of Collagen IV. Liu et al. use a genetic analysis to show that Tango1 is required to spatially maintain the size and integrity of ER exit site–Golgi units and that loss of Tango1 function impairs not only Collagen IV secretion but also general secretion.

Chloride is ubiquitous in physiology but understood to provide ionic strength for tissue function. The authors discover a molecular function of chloride whereby the ion signals the assembly of collagen IV, establishing a microenvironment on the outside of cells.

ZSM-5 that uses TPAOH as a template has an Al-rich exterior and defective Si-rich interior; thus, a simple base leaching selectively removed the Si-rich interior while the Al-rich exterior was protected. This catalyst showed no change in stability comparing with parent ZSM-5 during the MTP reaction that was attributed to the enclosed hollow structure and richly acidic outer shell. A preliminary fluorination, however, both removed defective Si-sites and caused distortion in tetrahedral aluminum that made the outer shell susceptible to alkaline treatment. These distorted tetrahedral Al were mostly leached out by NaOH in 1 min. Furthermore, aluminum in the filtrate was slowly redeposited onto the zeolite, serving as external pore-directing agents to control silicon dissolution from the Si-rich interior. This dealumination-realumination alkaline treatment process led to a higher solid yield and a uniform opened-mesopore structure with mesopores around 13 nm in diameter. This material was characterized by SEM, TEM, N adsorption, and mercury porosimetry. In addition, NH-TPD, OH-IR, Al MAS NMR, andH MAS NMR results demonstrated that the reinserted Al were unlike the framework Al, contributing less to acidity. The dealumination-realumination process, therefore, was also capable of tuning the acidity of the mesoporous ZSM-5. This mesoporous catalyst exhibited a longer lifetime and a higher propylene selectivity than other catalysts with an enclosed mesopore structure.

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