Whole-Genome Sequencing of a 900-Year-Old Human Skeleton Supports Two Past Migration Events from the Russian Far East to Northern Japan.

Recent studies on paleogenomics have reported some Paleolithic and Neolithic genomes that have provided new insights into the human population history in East and Northeast Asia. However, there remain some cases where more recent migration events need to be examined to elucidate the detailed formation process of local populations. Although the area around northern Japan is one of the regions archaeologically suggested to have been affected by migration waves after the Neolithic period, the genetic source of these migrations are still unclear. Thus, genomic data from such past migrant populations would be highly informative to clarify the detailed formation process of local populations in this region. Here, we report the genome sequence of a 900-year-old adult female (NAT002) belonging to the prehistoric Okhotsk people, who have been considered to be the past migrants to northern Japan after the Neolithic period. We found a close relationship between NAT002 and modern Lower Amur populations and past admixture events between the Amur, Jomon, and Kamchatka ancestries. The admixture dating suggested migration of Amur-related ancestry at approximately 1,600 BP, which is compatible with the archaeological evidence regarding the settlement of the Okhotsk people. Our results also imply migration of Kamchatka-related ancestry at approximately 2,000 BP. In addition, human leukocyte antigen (HLA) typing detected the HLA-B*40 allele, which is reported to increase the risk of arthritis, suggesting the genetic vulnerability of NAT002 to hyperostosis, which was observed around her chest clavicle.

Exploring correlations in genetic and cultural variation across language families in northeast Asia.

Culture evolves in ways that are analogous to, but distinct from, genomes. Previous studies examined similarities between cultural variation and genetic variation (population history) at small scales within language families, but few studies have empirically investigated these parallels across language families using diverse cultural data. We report an analysis comparing culture and genomes from in and around northeast Asia spanning 11 language families. We extract and summarize the variation in language (grammar, phonology, lexicon), music (song structure, performance style), and genomes (genome-wide SNPs) and test for correlations. We find that grammatical structure correlates with population history (genetic history). Recent contact and shared descent fail to explain the signal, suggesting relationships that arose before the formation of current families. Our results suggest that grammar might be a cultural indicator of population history while also demonstrating differences among cultural and genetic relationships that highlight the complex nature of human history.

Ancient Jomon genome sequence analysis sheds light on migration patterns of early East Asian populations.

Anatomically modern humans reached East Asia more than 40,000 years ago. However, key questions still remain unanswered with regard to the route(s) and the number of wave(s) in the dispersal into East Eurasia. Ancient genomes at the edge of the region may elucidate a more detailed picture of the peopling of East Eurasia. Here, we analyze the whole-genome sequence of a 2,500-year-old individual (IK002) from the main-island of Japan that is  characterized with a typical Jomon culture. The phylogenetic analyses support multiple waves of migration, with IK002 forming a basal lineage to the East and Northeast Asian genomes examined, likely representing some of the earliest-wave migrants who went north from Southeast Asia to East Asia. Furthermore, IK002 shows strong genetic affinity with the indigenous Taiwan aborigines, which may support a coastal route of the Jomon-ancestry migration. This study highlights the power of ancient genomics to provide new insights into the complex history of human migration into East Eurasia.

The prehistoric peopling of Southeast Asia.

The human occupation history of Southeast Asia (SEA) remains heavily debated. Current evidence suggests that SEA was occupied by Hòabìnhian hunter-gatherers until ~4000 years ago, when farming economies developed and expanded, restricting foraging groups to remote habitats. Some argue that agricultural development was indigenous; others favor the "two-layer" hypothesis that posits a southward expansion of farmers giving rise to present-day Southeast Asian genetic diversity. By sequencing 26 ancient human genomes (25 from SEA, 1 Japanese Jomon), we show that neither interpretation fits the complexity of Southeast Asian history: Both Hòabìnhian hunter-gatherers and East Asian farmers contributed to current Southeast Asian diversity, with further migrations affecting island SEA and Vietnam. Our results help resolve one of the long-standing controversies in Southeast Asian prehistory.

Hybridization of powdery mildew strains gives rise to pathogens on novel agricultural crop species.

Throughout the history of agriculture, many new crop species (polyploids or artificial hybrids) have been introduced to diversify products or to increase yield. However, little is known about how these new crops influence the evolution of new pathogens and diseases. Triticale is an artificial hybrid of wheat and rye, and it was resistant to the fungal pathogen powdery mildew (Blumeria graminis) until 2001 (refs. 1,2,3). We sequenced and compared the genomes of 46 powdery mildew isolates covering several formae speciales. We found that B. graminis f. sp. triticale, which grows on triticale and wheat, is a hybrid between wheat powdery mildew (B. graminis f. sp. tritici) and mildew specialized on rye (B. graminis f. sp. secalis). Our data show that the hybrid of the two mildews specialized on two different hosts can infect the hybrid plant species originating from those two hosts. We conclude that hybridization between mildews specialized on different species is a mechanism of adaptation to new crops introduced by agriculture.

Human genetic research, race, ethnicity and the labeling of populations: recommendations based on an interdisciplinary workshop in Japan.

BACKGROUND: A challenge in human genome research is how to describe the populations being studied. The use of improper and/or imprecise terms has the potential to both generate and reinforce prejudices and to diminish the clinical value of the research. The issue of population descriptors has not attracted enough academic attention outside North America and Europe. In January 2012, we held a two-day workshop, the first of its kind in Japan, to engage in interdisciplinary dialogue between scholars in the humanities, social sciences, medical sciences, and genetics to begin an ongoing discussion of the social and ethical issues associated with population descriptors. DISCUSSION: Through the interdisciplinary dialogue, we confirmed that the issue of race, ethnicity and genetic research has not been extensively discussed in certain Asian communities and other regions. We have found, for example, the continued use of the problematic term, "Mongoloid" or continental terms such as "European," "African," and "Asian," as population descriptors in genetic studies. We, therefore, introduce guidelines for reporting human genetic studies aimed at scientists and researchers in these regions. CONCLUSION: We need to anticipate the various potential social and ethical problems entailed in population descriptors. Scientists have a social responsibility to convey their research findings outside of their communities as accurately as possible, and to consider how the public may perceive and respond to the descriptors that appear in research papers and media articles.

A comprehensive map of the influenza A virus replication cycle.

BACKGROUND: Influenza is a common infectious disease caused by influenza viruses. Annual epidemics cause severe illnesses, deaths, and economic loss around the world. To better defend against influenza viral infection, it is essential to understand its mechanisms and associated host responses. Many studies have been conducted to elucidate these mechanisms, however, the overall picture remains incompletely understood. A systematic understanding of influenza viral infection in host cells is needed to facilitate the identification of influential host response mechanisms and potential drug targets. DESCRIPTION: We constructed a comprehensive map of the influenza A virus ('IAV') life cycle ('FluMap') by undertaking a literature-based, manual curation approach. Based on information obtained from publicly available pathway databases, updated with literature-based information and input from expert virologists and immunologists, FluMap is currently composed of 960 factors (i.e., proteins, mRNAs etc.) and 456 reactions, and is annotated with ~500 papers and curation comments. In addition to detailing the type of molecular interactions, isolate/strain specific data are also available. The FluMap was built with the pathway editor CellDesigner in standard SBML (Systems Biology Markup Language) format and visualized as an SBGN (Systems Biology Graphical Notation) diagram. It is also available as a web service (online map) based on the iPathways+ system to enable community discussion by influenza researchers. We also demonstrate computational network analyses to identify targets using the FluMap. CONCLUSION: The FluMap is a comprehensive pathway map that can serve as a graphically presented knowledge-base and as a platform to analyze functional interactions between IAV and host factors. Publicly available webtools will allow continuous updating to ensure the most reliable representation of the host-virus interaction network. The FluMap is available at http://www.influenza-x.org/flumap/.

A methodical microarray design enables surveying of expression of a broader range of genes in Ciona intestinalis.

We provide a new oligo-microarray for Ciona intestinalis, based on the NimbleGen 12-plex×135k format. The array represents 106,285 probes, which is more than double the probe number of the currently available 44k microarray. These probes cover 99.2% of the transcripts in the KyotoHoya (KH) models, published in 2008, and they contain 81.1% of the entries in the UniGene database that are not included in the KH models. In this paper, we show that gene expression levels measured by this new 135k microarray are highly correlated with those obtained by the existing 44k microarray for genes common to both arrays. We also investigated gene expression using samples obtained from the ovary and the neural complex of adult C. intestinalis, showing that the expression of tissue-specific genes is consistent with previous reports. Approximately half of the highly expressed genes identified in the 135k microarray are not included in the previous microarray. The high coverage of gene models by this microarray made it possible to identify splicing variants for a given transcript. The 135k microarray is useful in investigating the functions of genes that are not yet well characterized. Detailed information about this 135k microarray is accessible at no charge from supplemental materials, NCBI Gene Expression Omnibus (GEO), and http://marinegenomics.oist.jp.

Circadian clock in Ciona intestinalis revealed by microarray analysis and oxygen consumption.

The molecular mechanisms of the endogenous circadian clocks that allow most animals to adapt to environmental cycles have recently been uncovered. The draft genome of the ascidian, Ciona intestinalis, a model animal that is close to vertebrates, has been described. However, the C. intestinalis genome lacks the canonical clock genes such as Per, Bmal and Clock that are shared by vertebrates and insects. Here, we found the circadian rhythms at the physiological and molecular levels. The oxygen consumption rate was lower during the light phase and higher during the dark phase during a day, and the rhythm highly damped and continued under constant darkness. From the microarray analysis, the 396 spots (1.8% of the total; corresponding to 388 clones) were extracted as candidates for circadian expression. We confirmed the circadian expression of several candidate genes by northern blotting. Furthermore, three of four rhythmic expressed genes showed phase-shifts to prolonged light period. However, most of known clock genes did not oscillate. These data suggest that C. intestinalis have a unique molecular circadian clock and the daily environmental change is not such a strong effect for sea squirt in its evolution when compared to vertebrates and insects.