Attention Should be Drawn to Rare Diseases and Interpretation of Sequence Variants

The last Monday in February is the ＂Rare Disease Day＂ every year. This year the theme of it is ＂Join us in making the voice of rare diseases heard＂, proposed by World Health Organization （http：//www.rarediseaseday.org）. Rare diseases are a group of serious chronic diseases, with a high morbidity and mortality rates.

Diversity and geographical distribution of haptophyte Phaeocystis in the Chinese seas based on metabarcoding analysis

Phaeocystis is an important bloom-forming species and over 100 blooms have occurred since 1997 along the Chinese coasts,while only the species P.globosa was described.In this project,a total of 246 phytoplankton samples collected from the Bohai Sea,the Yellow Sea,and the East China Sea in April 2021 were analyzed to evaluate the species diversity and geographical distribution of the genus Phaeocystis based on metabarcoding 18S r DNA sequence.Four described Phaeocystis species were recognized,including P.globosa,P.pouchetii,P.jahnii,and P.cordata,and each has distinguished geographical distribution characteristics.P.globosa was the most widespread and abundant species,and P.pouchetii was found in the Bohai Sea and the northern Yellow Sea with substantially elevated abundance.P.cordata was also a widespread species,but its abundance was relatively low,while P.jahnii gathered only in the southeastern East China Sea.Water temperature,phosphate as well as ammonium contents were found to be associated with the abundance of P.globosa,P.pouchetii,and P.jahnii significantly.Moreover,two uncharacterized Phaeocystis species were detected in the Chinese seas,indicating the diversity of the genus remains underestimated worldwide.

Microbiome Diversity Analysis of the Bacterial Community in Idah River, Kogi State, Nigeria

The analysis of bacterial diversity in aquatic systems particularly in rivers, lakes, and streams can provide useful data on the effect of anthropogenic activities on such water bodies to humans and fishes. Idah River, the focal point of this study, is an offshoot of the two major Nigerian rivers characterized by observed human activities and pollution sources. Water samples were collected from four designated sites and assessed for their bacterial assemblages and structure, using PacBio Single-Molecule Real-Time (SMRT) sequencing technology. The full length of the 16S rRNA gene was sequenced, and Amplicon Sequence Variants were generated using the DADA2 workflow optimised for PacBio long-read amplicons in Rstudio. A total of 8751 high-quality reads obtained were taxonomically classified as 24 phyla, 42 classes, 84 orders, 125 families, 156 genera, and 106 species. Taxonomical composition revealed Proteobacteria as the most abundant phyla across all sample sites. At the genera level, Azospira (57.03%) was the most dominant ASV in Docking Point A, while Acinetobacter (66.67%) was the most abundant ASV in Docking Point B. In Idah Axis Confluence, hgcl clade (65.66%) was the most prevalent ASV, whereas Holophaga (42.86%) was the most common ASV in Idah Axis Midstream. Genera analysis also revealed that 12.9% of the total ASVs were discovered across all sample sites. Among these were pathogenic bacteria, reducers, and degraders of domestic and animal wastes. Observed results provide evidence that sampled sites of Idah River are contaminated, most likely through constant human activities and thus, could have an impact on resident fishes as well. This study, therefore, agrees with a previous report from the river, which used standard microbial procedures. However, next-generation sequencing techniques employed revealed more bacterial community than the former, including unresolved taxonomic sequences that may be novel.

Identification of a LMNA (c.646C>T) variant by whole-exome sequencing in combination with a dilated cardiomyopathy (DCM) related gene filter in a family with familiar DCM

Dilated cardiomyopathy（DCM）is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM concomitant with arrhythmias and sudden death resulting from gene mutation has been widely

Main environmental drivers of abundance,diversity and community structure of comammox Nitrospira in paddy soils

The recently discovered complete ammonia oxidizers comammox Nitrospira contain clades A and B that can establish an independent one-step nitrification process;however,little is known about their environmental drivers or habitat distributions in agricultural soils.Previous studies on comammox Nitrospira in paddy soils have mainly focused on small-scale samples,and there is a lack of multisite research on comammox Nitrospira in paddy soils.In this study,we conducted a survey of 36 paddy soils to understand the community structure,abundance,and diversity of comammox Nitrospira and the degree to which they are affected by environmental factors at a large scale.Comammox Nitrospira were found to be widely distributed among the paddy soils.The abundance of comammox Nitrospira clade A was mostly lower than that of clade B,whereas its diversity was mostly higher than that of clade B.Correlation analysis showed that multiple factors affected(P<0.05)the abundance of comammox Nitrospira,including soil pH,organic matter,total carbon,and total nitrogen,latitude,mean annual temperature,and mean annual precipitation.Moreover,there was a clear relationship between the comammox Nitrospira community and habitat,indicating that some amplicon sequence variants(ASVs)had a unique dominant position in specific habitats.Phylogenetic analysis showed that the ASVs of comammox Nitrospira clade A clustered with the known sequences in the paddy soils and were significantly different from the known sequences in other habitats,which may be related to the unique paddy field habitat.In contrast,comammox Nitrospira clade B showed no clear habitat dependence.These results support the wide distribution and high abundance of comammox Nitrospira in paddy soils and provide novel insights into nitrogen cycling and nutrient management in agricultural ecosystems.

The Role of Quality Control in Targeted Next-generation Sequencing Library Preparation

Next-generation sequencing （NGS） is getting routinely used in the diagnosis of hereditary diseases, such as human cardiomyopathies. Hence. it is of utter importance to secure high quality sequencing data, enabling the identification of disease-relevant mutations or the conclusion of negative test results. During the process of sample preparation, each protocol for target enrichment library preparation has its own requirements for quality control （QC）; however, there is little evi- dence on the actual impact of these guidelines on resulting data quality. In this study, we analyzed the impact of QC during the diverse library preparation steps of Agilent SureSelect XT target enrichment and lllumina sequencing. We quantified the parameters for a cohort of around 600 samples, which include starting amount of DNA, amount of sheared DNA, smallest and largest fragment size of the starting DNA; amount of DNA after the pre-PCR, and smallest and largest fragment size of the resulting DNA; as well as the amount of the final library, the corresponding smallest and largest fragment size, and the number of detected variants. Intriguingly, there is a high tolerance for variations in all QC steps, meaning that within the boundaries proposed in the current study, a considerable variance at each step of QC can be well tolerated without compromising NGS quality.

Next generation sequencing of Y-STRs in father-son pairs and comparison with traditional capillary electrophoresis

To evaluate the promising advantages of massively parallel sequencing(MPS)in our casework,we analysed a total of 33 Y-chromosomal short tandem repeats(Y-STRs)with traditional capillary electrophoresis(CE)and 25 Y-STRs using the newer MPS technology.We studied the outcome of both technologies in 64 father-son pairs using stock and custom-designed kits.Current MPS technology confirmed the 13 mutational events observed with CE and improved our understanding of the complex nature of STR mutations.By detecting isometric sequence variants between unrelated males,we show that sequencing Y-STRs using MPS can boost discrimination power.

Genetic studies of schizophrenia:an update

Schizophrenia（SCZ） is a complex and heterogeneous mental disorder that affects about 1% of global population. In recent years,considerable progress has been made in genetic studies of SCZ. A number of common variants with small effects and rare variants with relatively larger effects have been identifi ed. These variants include risk loci identifi ed by genome-wide association studies,rare copy-number variants identifi ed by comparative genomic analyses,and de novo mutations identified by high-throughput DNA sequencing. Collectively,they contribute to the heterogeneity of the disease. In this review,we update recent discoveries in the fi eld of SCZ genetics,and outline the perspectives of future directions.

Analysis of Allele Specific Expression——A Survey

Allele specific expression is essential for cellular programming and development and the diversity of cellular phenotypes. Traditional analysis methods utilize RNA and depend on single nucleotide polymorphisms,thus to suffer from limited amount of materials for analysis. The rapid development of next-generation sequencing technologies provides more comprehensive and powerful approaches to analyze the genomic, epigenetic, and transcriptomic data, and further to detect and measure allele specific expressions. It will potentially enhance the understanding of the allele specific expressions, their complexities, and the effect on biological processes. In this paper, we extensively review the state-of-art enabling technologies and tools to analyze, detect, and measure allele specific expressions, compare their features, and point out the future trend of the methods.