For more than 100 years, the fruit fly Drosophila melanogaster has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula Drosophilae , that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to >250 distinct cell types. We provide an in-depth analysis of cell type–related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal. Analysis of common cell types between tissues, such as blood and muscle cells, reveals rare cell types and tissue-specific subtypes. This atlas provides a valuable resource for the Drosophila community and serves as a reference to study genetic perturbations and disease models at single-cell resolution.

Alkane hydroxylases, including the integral-membrane non-haem iron monooxygenase (AlkB) and cytochrome P450 CYP153 family, are key enzymes in bacterial alkane oxidation. Although both genes have been detected in a number of bacteria and environments, knowledge about the diversity of these genes in marine alkane-degrading bacteria is still limited, especially in pelagic areas. In this report, 177 bacterial isolates, comprising 43 genera, were obtained from 18 oil-degrading consortia enriched from surface seawater samples collected from the Atlantic Ocean. Many isolates were confirmed to be the first oil-degraders in their affiliated genera including Brachybacterium, Idiomarina, Leifsonia, Martelella, Kordiimonas, Parvibaculum and Tistrella. Using degenerate PCR primers, alkB and CYP153A P450 genes were surveyed in these bacteria. In total, 82 P450 and 52 alkB gene fragments were obtained from 80 of the isolates. These isolates mainly belonged to Alcanivorax, Bacillus, Erythrobacter, Martelella, Parvibaculum and Salinisphaera, some of which were reported, for the first time, to encode alkane hydroxylases. Phylogenetic analysis showed that both genes were quite diverse and formed several clusters, most of which were generated from various Alcanivorax bacteria. Noticeably, some sequences, such as those from the Salinisphaera genus, were grouped into a distantly related novel cluster. Inspection of the linkage between gene and host revealed that alkB and P450 tend to coexist in Alcanivorax and Salinisphaera, while in all isolates of Parvibaculum, only P450 genes were found, but of multiple homologues. Multiple homologues of alkB mostly cooccurred in Alcanivorax isolates. Conversely, distantly related isolates contained similar or even identical sequences. In summary, various oil-degrading bacteria, which harboured diverse P450 and alkB genes, were found in the surface water of Atlantic Ocean. Our results help to show the diversity of P450 and alkB genes in prokaryotes, and to portray the geographic distribution of oil-degrading bacteria in marine environments.

Alcanivorax dieselolei strain B-5 is a marine bacterium that can utilize a broad range of n-alkanes (C(5) -C(36) ) as sole carbon source. However, the mechanisms responsible for this trait remain to be established. Here we report on the characterization of four alkane hydroxylases from A. dieselolei, including two homologues of AlkB (AlkB1 and AlkB2), a CYP153 homologue (P450), as well as an AlmA-like (AlmA) alkane hydroxylase. Heterologous expression of alkB1, alkB2, p450 and almA in Pseudomonas putida GPo12 (pGEc47ΔB) or P. fluorescens KOB2Δ1 verified their functions in alkane oxidation. Quantitative real-time RT-PCR analysis showed that these genes could be induced by alkanes ranging from C(8) to C(36) . Notably, the expression of the p450 and almA genes was only upregulated in the presence of medium-chain (C(8) -C(16) ) or long-chain (C(22) -C(36) ) n-alkanes, respectively; while alkB1 and alkB2 responded to both medium- and long-chain n-alkanes (C(12) -C(26) ). Moreover, branched alkanes (pristane and phytane) significantly elevated alkB1 and almA expression levels. Our findings demonstrate that the multiple alkane hydroxylase systems ensure the utilization of substrates of a broad chain length range.

Alkanes are major constituents of crude oil. They are also present at low concentrations in diverse non-contaminated because many living organisms produce them as chemo-attractants or as protecting agents against water loss. Alkane degradation is a widespread phenomenon in nature. The numerous microorganisms, both prokaryotic and eukaryotic, capable of utilizing alkanes as a carbon and energy source, have been isolated and characterized. This review summarizes the current knowledge of how bacteria metabolize alkanes aerobically, with a particular emphasis on the oxidation of long-chain alkanes, including factors that are responsible for chemotaxis to alkanes, transport across cell membrane of alkanes, the regulation of alkane degradation gene and initial oxidation.

Alkane-degrading bacteria are ubiquitous in marine environments, but little is known about how alkane degradation is regulated. Here we investigate alkane sensing, chemotaxis, signal transduction, uptake and pathway regulation in Alcanivorax dieselolei. The outer membrane protein OmpS detects the presence of alkanes and triggers the expression of an alkane chemotaxis complex. The coupling protein CheW2 of the chemotaxis complex, which is induced only by long-chain (LC) alkanes, sends signals to trigger the expression of Cyo, which participates in modulating the expression of the negative regulator protein AlmR. This change in turn leads to the expression of ompT1 and almA, which drive the selective uptake and hydroxylation of LC alkanes, respectively. AlmA is confirmed as a hydroxylase of LC alkanes. Additional factors responsible for the metabolism of medium-chain-length alkanes are also identified, including CheW1, OmpT1 and OmpT2. These results provide new insights into alkane metabolism pathways from alkane sensing to degradation.

In this report, the diversity of oil-degrading bacteria and alkB gene was surveyed in the seawater around Xiamen Island. Forty-four isolates unique in 16S rRNA sequence were obtained after enrichment with crude oil. Most of the obtained isolates exhibited growth with diesel oil and crude oil. alkB genes were positively detected in 16 isolates by degenerate polymerase chain reaction (PCR). And for the first time, alkB genes were found in bacteria of Gallaecimonas, Castellaniella, Paracoccus, and Leucobacter. Additional 29 alkB sequences were retrieved from genomic DNA of the oil-degrading communities. Phylogenetic analysis showed that the obtained alkB genes formed five groups, most of which exhibited 60-80% similarity at the amino acid level with sequences retrieved from the GenBank database. Furthermore, the abundance of alkB genes in seawater was examined by real-time PCR. The results showed that alkB genes of each group in situ ranged from about 3 × 10(3) to 3 × 10(5) copies L(-1), with the homologs of Alcanivorax and Pseudomonas being the most predominant. Bacteria of Alcanivorax, Acinetobacter, and Pseudomonas are important oil degraders in this area; while those frequently reported in other area, like Oleiphilus spp., Oleispira spp., and Thalassolituus spp. were not found in our report. These results indicate that bacteria and genes involved in oil degradation are quite diverse, and may have restriction in geographic distribution in some species.

This study describes the epidemiology and clinical characteristics of patients hospitalized for ocular trauma in South-Central China. Notably, a high rate of firework-related ocular trauma occurred during the months adjacent to the Chinese New Year festival. Specific injury prevention strategies, such as the use of protective eyewear, need to target the workplace to reduce the incidence and severity of ocular trauma.

Iodinated contrast media serves as a direct causative factor of acute kidney injury (AKI) and is involved in the progression of cellular dysfunction and apoptosis. Emerging evidence indicates that NLRP3 inflammasome triggers inflammation, apoptosis and tissue injury during AKI. Nevertheless, the underlying renoprotection mechanism of NLRP3 inflammasome against contrast-induced AKI (CI-AKI) was still uncertain. This study investigated the role of NLRP3 inflammasome in CI-AKI both in vitro and in vivo. In HK-2 cells and unilateral nephrectomy model, NLRP3 and NLRP3 inflammasome member ASC were significantly augmented with the treatment of contrast media. Moreover, genetic disruption of NLRP3 notably reversed contrast-induced expression of apoptosis related proteins and secretion of proinflammatory factors, similarly to the effects of ASC deletion. Consistent with above results, absence of NLRP3 in mice undergoing unilateral nephrectomy also protected against contrast media-induced renal cells phenotypic alteration and cell apoptosis via modulating expression level of apoptotic proteins. Collectively, we demonstrated that NLRP3 inflammasome mediated CI-AKI through modulating the apoptotic pathway, which provided a potential therapeutic target for the treatment of contrast media induced acute kidney injury.