Microbes have central roles in ocean food webs and global biogeochemical processes, yet specific ecological relationships among these taxa are largely unknown. This is in part due to the dilute, microscopic nature of the planktonic microbial community, which prevents direct observation of their interactions. Here, we use a holistic (that is, microbial system-wide) approach to investigate time-dependent variations among taxa from all three domains of life in a marine microbial community. We investigated the community composition of bacteria, archaea and protists through cultivation-independent methods, along with total bacterial and viral abundance, and physicochemical observations. Samples and observations were collected monthly over 3 years at a welldescribed ocean time-series site of southern California. To find associations among these organisms, we calculated time-dependent rank correlations (that is, local similarity correlations) among relative abundances of bacteria, archaea, protists, total abundance of bacteria and viruses and physico-chemical parameters. We used a network generated from these statistical correlations to visualize and identify time-dependent associations among ecologically important taxa, for example, the SAR11 cluster, stramenopiles, alveolates, cyanobacteria and ammonia-oxidizing archaea. Negative correlations, perhaps suggesting competition or predation, were also common. The analysis revealed a progression of microbial communities through time, and also a group of unknown eukaryotes that were highly correlated with dinoflagellates, indicating possible symbioses or parasitism. Possible 'keystone' species were evident. The network has statistical features similar to previously described ecological networks, and in network parlance has non-random, small world properties (that is, highly interconnected nodes). This approach provides new insights into the natural history of microbes.

Human Y-chromosome haplogroup structure is largely circumscribed by continental boundaries. One notable exception to this general pattern is the young haplogroup R1a that exhibits post-Glacial coalescent times and relates the paternal ancestry of more than 10% of men in a wide geographic area extending from South Asia to Central East Europe and South Siberia. Its origin and dispersal patterns are poorly understood as no marker has yet been described that would distinguish European R1a chromosomes from Asian. Here we present frequency and haplotype diversity estimates for more than 2000 R1a chromosomes assessed for several newly discovered SNP markers that introduce the onset of informative R1a subdivisions by geography. Marker M434 has a low frequency and a late origin in West Asia bearing witness to recent gene flow over the Arabian Sea. Conversely, marker M458 has a significant frequency in Europe, exceeding 30% in its core area in Eastern Europe and comprising up to 70% of all M17 chromosomes present there. The diversity and frequency profiles of M458 suggest its origin during the early Holocene and a subsequent expansion likely related to a number of prehistoric cultural developments in the region. Its primary frequency and diversity distribution correlates well with some of the major Central and East European river basins where settled farming was established before its spread further eastward. Importantly, the virtual absence of M458 chromosomes outside Europe speaks against substantial patrilineal gene flow from East Europe to Asia, including to India, at least since the mid-Holocene.

The temporal community dynamics and persistence of different viral types in the marine environment are still mostly obscure. Polymorphism of the major capsid protein gene, g23, was used to investigate the community composition dynamics of T4-like myoviruses in a North Atlantic fjord for a period of 2 years. A total of 160 unique operational taxonomic units (OTUs) were identified by terminal restriction fragment length polymorphism (TRFLP) of the gene g23. Three major community profiles were identified (winter-spring, summer, and autumn), which resulted in a clear seasonal succession pattern. These seasonal transitions were recurrent over the 2 years and significantly correlated with progression of seawater temperature, Synechococcus abundance, and turbidity. The appearance of the autumn viral communities was concomitant with the occurrence of prominent Synechococcus blooms. As a whole, we found a highly dynamic T4-like viral community with strong seasonality and recurrence patterns. These communities were unexpectedly dominated by a group of persistently abundant viruses.

Crohn's disease causes chronic inflammation in the gastrointestinal tract and its pathogenesis remains unclear. In the intestine of Crohn's disease patients, CD14 + CD11 + CD163 low macrophages contribute to inflammation through the induction of Th17 cells and production of inflammatory cytokines; the CD14 + CD11c + 163 high fraction is anti-inflammatory through the production of IL-10 in normal cases. In this report, the 16S rRNA gene amplicon sequencing method was used to identify bacteria that are specifically present in intestinal CD14 + CD11c + macrophages of crohn's disease patients. Bacteria present in intestinal CD14 + CD11c + macrophages and mucus of crohn's disease patients were separated into different clusters in principal coordinates analysis. There was a statistically significant increase in the relative composition of CD14 + CD11c + macrophages from mucus in two phyla (Proteobacteria [p = 0.01] and Actinobacteria [p = 0.02]) and two families (Moraxellaceae [p < 0.001] and Pseudomonadaceae [p = 0.01]). In addition, OTU-1: Acinetobacter and OTU-8: Pseudomonadaceae tended to concentrate in the CD14 + CD11c + CD163 low subset, whereas OTU-10: Proteus, OTU-15: Collinsella tended to concentrate more in the CD14 + CD11c + CD163 high subset than the other subset and mucus.Crohn's disease causes chronic inflammation in the gastrointestinal tract and is known as inflammatory bowel disease (IBD) together with ulcerative colitis, yet fundamental therapy has not yet been established. Inflammatory reactions are usually controlled in the intestinal tract and intestinal homeostasis is maintained. In IBD, chronic inflammation is thought to occur by maintaining an excessively activated state of immune cells through the involvement of several factors, including genetic factors, environmental factors, immune abnormality, and intestinal bacteria 1,2 .In the intestinal tract of Crohn's disease, CD14 + macrophages are increased compared to normal intestine. CD14 + macrophages are more ability to produce inflammatory cytokines such as IL-23, TNF-α, and IL-6 than CD14 − macrophages 3 . CD14 + macrophages also have the ability to induce Th17 cells, but in the intestines of

Over two decades of research have indicated that viruses play crucial roles in aquatic food webs as active constituents of the microbial loop and in the population ecology of both prokaryotic and eukaryotic microorganisms. Over the past 5 years, there has been a sharp increase in reported aquatic virus research, notably in the areas of freshwater viral ecology, viruses of eukaryotic microorganisms and viral genetic diversity. Recent studies of the interactions between viral infection, bacterivory and grazing have demonstrated the complex dynamics of viral infection within aquatic ecosystems. These reports have helped solidify our understanding of the environmental controls on viral abundance, impacts of viral infection upon host community structure and have elucidated new roles of viruses in biogeochemical cycles – such as photosystem gene expression. Previously unrecognised groups of viruses ( ribonucleic acid viruses and single‐stranded deoxyribonucleic acid viruses) have also been revealed as diverse and active components of marine virioplankton assemblages. Key Concepts: Viruses are the most numerically dominant organisms on earth, and their abundance varies between habitats, often according to local primary productivity. Both viral activity and bacterivory contribute significantly to bacterial mortality in aquatic ecosystems, which in turn influence global‐scale biogeochemical cycles. Methodological advances, such as metagenomics and genomics, have greatly facilitated studies of marine viruses and resulted in key discoveries on viral diversity, viral–host gene transfer and viral influence on host cell physiology. Photosystem genes are common in cyanophage and are hypothesised to enhance viral production rates. Viral‐induced mortality may be a key factor in controlling or terminating algal blooms.