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ABSTRACT The environmental DNA (eDNA) approach is an emerging tool for monitoring marine biodiversity. However, the sampling effort needs optimization according to the site characteristics and target taxonomic groups. In this study, we optimized the eDNA sampling effort in terms of sample volume and number of replicates to monitor the diversity of marine vertebrates (mainly fish) in Hong Kong's subtropical waters that show a gradient of estuarine to oceanic waters. To maximize detection, we used three pairs of metabarcoding primers (12S‐v5, MiFish‐U, and MiFish‐E). We compared vertebrate diversity in 78 water samples, ranging from 1 to 10 L, collected from oceanic and estuarine sites. Metabarcoding yielded a total of 140 vertebrate species, of which 18 were unique to the estuarine site, 66 unique to the oceanic site, and 56 shared between both sites. The detected species were predominantly ray‐finned fish (136 species), and the three primer pairs exhibited differential sensitivity toward different taxa, especially cartilaginous fish and cetaceans. Increasing sampling volume per replicate generally increased the total detected species, average species per replicate, and species coverage, and sampling 3 or 4 × 4 L represented the most efficient sampling effort for the estuarine and oceanic sites, respectively. The diversity analysis revealed that sampling >2 L per replicate reduced variability and improved diversity analysis. The results also showed that a larger sampling volume per replicate increased the probability of detecting endangered, indicator, invasive, and elusive species, with 4 L representing the most efficient volume. This study recommended sampling 4 L per replicate and 3 replicates for estuarine and 4 for oceanic sites, respectively for effectively monitoring marine fish in subtropical waters using the eDNA approach.

Abstract Gut microbiota can influence host gene expression and physiology through metabolites. Besides, the presence or absence of gut microbiome can reprogram host transcriptome and epitranscriptome as represented by N6‐methyladenosine (m6A), the most abundant mammalian mRNA modification. However, which and how gut microbiota‐derived metabolites reprogram host transcriptome and m6A epitranscriptome remain poorly understood. Here, investigation is conducted into how gut microbiota‐derived metabolites impact host transcriptome and m6A epitranscriptome using multiple mouse models and multi‐omics approaches. Various antibiotics‐induced dysbiotic mice are established, followed by fecal microbiota transplantation (FMT) into germ‐free mice, and the results show that bile acid metabolism is significantly altered along with the abundance change in bile acid‐producing microbiota. Unbalanced gut microbiota and bile acids drastically change the host transcriptome and the m6A epitranscriptome in multiple tissues. Mechanistically, the expression of m6A writer proteins is regulated in animals treated with antibiotics and in cultured cells treated with bile acids, indicating a direct link between bile acid metabolism and m6A biology. Collectively, these results demonstrate that antibiotic‐induced gut dysbiosis regulates the landscape of host transcriptome and m6A epitranscriptome via bile acid metabolism pathway. This work provides novel insights into the interplay between microbial metabolites and host gene expression.

Abstract Plant movements for survival are nontrivial. Antheridia in the moss Physcomitrium patens (P. patens) use motion to eject sperm in the presence of water. However, the biological and mechanical mechanisms that actuate the process are unknown. Here, the burst of the antheridium of P. patens, triggered by water, results from elastic instability and is determined by an asymmetric change in cell geometry. The tension generated in jacket cell walls of antheridium arises from turgor pressure, and is further promoted when the inner walls of apex burst in hydration, causing water and cellular contents of apex quickly influx into sperm chamber. The outer walls of the jacket cells are strengthened by NAC transcription factor VNS4 and serve as key morphomechanical innovations to store hydrostatic energy in a confined space in P. patens. However, the antheridium in liverwort Marchantia polymorpha (M. polymorpha) adopts a different strategy for sperm release; like jacket cell outer walls of P. patens, the cells surrounding the antheridium of M. polymorpha appear to play a similar role in the storage of energy. Collectively, the work shows that plants have evolved different ingenious devices for sperm discharge and that morphological innovations can differ.

Abstract The spatial and temporal characteristics of the factors influencing metro passenger flow are basic phenomena reflecting the environment‐land relationship. Existing studies tend to focus more on the characteristics of metro trips and the static built environment. One of the outstanding contributions of this paper is to expand the scope of the factors influencing the built environment of metro stations and explore the spatial differentiation and pattern characteristics of the static and dynamic environments. This paper provides additional empirical insights into spatiotemporal influencing factors of metro mobility patterns from the dynamic perspective. The results show spatial and temporal heterogeneity between four types of metro stations and their influencing factors. 21.59% of the stations are in in active areas, while the distribution of parking lots has a positive effect on metro passenger flow; 29.55% of the stations belong to integrated residential areas, and the number of residential areas is the dominant factor in such agglomerations; 38.64% of the areas belong to work areas, and such areas have the highest work‐related coefficients, but the work variable in the central city has a certain inhibiting effect; 10.23% of the stations are in commercial areas, which are mainly distributed within the central urban area.

Abstract Background Esophageal cancer is currently the eighth most common tumor in the world and a leading cause of cancer death. SULT2B1 plays crucial roles in tumorigenesis. The purpose of this study is to explore the role of SULT2B1 in esophageal squamous cell carcinoma (ESCC). Methods The expression of SULT2B1 and its clinicopathological characteristics were evaluated in ESCC cohorts. Bisulfite genomic sequencing and methylation specific PCR were used to detect the promoter hypermethylation of the SULT2B1 gene. The effects of SULT2B1 on the biological characters of ESCC cells were identified on functional assays. Subcutaneous xenograft models revealed the role of SULT2B1 in vivo with tumor growth. RNA‐Seq analysis and qRT‐PCR were performed to recognize the targeted effect of SULT2B1 on PER1. Results SULT2B1 was not expressed or at a low level in most patients with ESCC or in ESCC cell lines, and this was accompanied by poor clinical prognosis. Furthermore, the downregulation of SULT2B1 occurred in promoter hypermethylation. According to the functional results, overexpression of SULT2B1 could inhibit tumoral proliferation in vitro and retard tumor growth in vivo, whereas SULT2B1 knockdown could accelerate ESCC progression. Mechanistically, SULT2B1 targeted PER1 at the mRNA level during post‐transcriptional regulation. Finally, PER1 was verified as a suppressor and poor‐prognosis factor in ESCC. Conclusions SULT2B1 loss is a consequence owing to its ability to promote hypermethylation. In addition, it serves as a suppressor and poor‐prognosis factor because of the post‐transcriptional regulation of PER1 in ESCC.

Abstract In recent decades, a large number of label fusion methods have been introduced and applied to magnetic resonance brain image segmentation. This paper proposes a double‐weighted label fusion method to improve the segmentation accuracy of magnetic resonance brain tissues. In weighted label fusion methods, different weights are utilised for different neighbouring pixels around the central test pixel. The weight of one specific neighbouring pixel is determined by the structural similarity between the patch of the atlas that centred in the neighbouring pixel and the patch of the image to be segmented that centred in the central test pixel, which is referred to as a patch‐based label fusion scheme. This paper presents a double‐weighted label fusion method to improve the segmentation accuracy of magnetic resonance brain tissues. The proposed label fusion method adds another new type of weights to the neighbouring pixels around the central test pixel and this new type of weights are calculated based on the atlas information itself. Segmentation experiments of different brain tissues show that our method can improve the segmentation performance.

Abstract Introduction Leukodystrophy is a group of hereditary leukoencephalopathies predominantly affecting the white matter. Multiple genes and mutations have been reported to be associated with this disorder. Identification of pathogenic genes can facilitate diagnosis of leukodystrophy and development of therapeutic strategies. Methods A case was presented with clinical examinations. Exome sequencing was applied to identify potential mutations. Sanger sequencing of blood DNA was applied to confirm the mutation and to examine additional members. Results We reported a Chinese male patient of adult‐onset leukodystrophy. Genetic examinations identified a homozygous mutation, c. 452T>C (p. M151T), in alanyl‐tRNA synthetase 2 (AARS2) in the patient. The disease was autosomal recessive as suggested by the genotypic analyses of his family members. We also reviewed phenotypic spectra of AARS2 mutation‐associated leukodystrophies from a total of 16 reported cases. Conclusions Our data provide further evidence that mutations of AARS2 are implicated in adult‐onset leukodystrophy.