Seed dormancy has fundamental importance in plant survival and crop production; however, the mechanisms regulating dormancy remain unclear [1-3]. Seed dormancy levels generally decrease during domestication to ensure that crops successfully germinate in the field. However, reduction of seed dormancy can cause devastating losses in cereals like wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) due to pre-harvest sprouting, the germination of mature seed (grain) on the mother plant when rain occurs before harvest. Understanding the mechanisms of dormancy can facilitate breeding of crop varieties with the appropriate levels of seed dormancy [4-8]. Barley is a model crop [9, 10] and has two major seed dormancy quantitative trait loci (QTLs), SD1 and SD2, on chromosome 5H [11-19]. We detected a QTL designated Qsd2-AK at SD2 as the single major determinant explaining the difference in seed dormancy between the dormant cultivar "Azumamugi" (Az) and the non-dormant cultivar "Kanto Nakate Gold" (KNG). Using map-based cloning, we identified the causal gene for Qsd2-AK as Mitogen-activated Protein Kinase Kinase 3 (MKK3). The dormant Az allele of MKK3 is recessive; the N260T substitution in this allele decreases MKK3 kinase activity and appears to be causal for Qsd2-AK. The N260T substitution occurred in the immediate ancestor allele of the dormant allele, and the established dormant allele became prevalent in barley cultivars grown in East Asia, where the rainy season and harvest season often overlap. Our findings show fine-tuning of seed dormancy during domestication and provide key information for improving pre-harvest sprouting tolerance in barley and wheat.

The effects of climate events on the feeding ecology and trophic dynamics of Pacific salmon (Oncorhynchus spp.) in offshore waters of the central Gulf of Alaska were investigated during early summers (1994)(1995)(1996)(1997)(1998)(1999)(2000), based on analyses of stomach contents, and carbon and nitrogen stable isotopes (d 13 C and d 15 N). Gonatid squids (mainly Berryteuthis anonychus) were the dominant prey of all salmon species except for chum salmon (O. keta). During the 1997 El Niñ o event and the 1999 La Niñ a event, squids decreased sharply in the diets of all Pacific salmon except coho salmon (O. kisutch) in the Subarctic Current, and chum salmon diets changed from gelatinous zooplankton (1995-97) to a more diverse array of zooplankton species. A d 13 C and d 15 N analysis indicated that all salmon species occupied the same branch of the food web in 1999-2000. We hypothesize that high-seas salmon adapt to climate-induced changes in their prey resources by switching their diets either within or between trophic levels. To understand the effects of climate change on Pacific salmon in the Gulf of Alaska, biological oceanographic research on B. anonychus and other important prey resources is needed.

Ocean acidification, caused by increased atmospheric carbon dioxide (CO 2 ) concentrations, is currently an important environmental problem. It is therefore necessary to investigate the effects of ocean acidification on all life stages of a wide range of marine organisms. However, few studies have examined the effects of increased CO 2 on early life stages of organisms, including corals. Using a range of pH values (pH 7.3, 7.6, and 8.0) in manipulative duplicate aquarium experiments, we have evaluated the effects of increased CO 2 on early life stages (larval and polyp stages) of Acropora spp. with the aim of estimating CO 2 tolerance thresholds at these stages. Larval survival rates did not differ significantly between the reduced pH and control conditions. In contrast, polyp growth and algal infection rates were significantly decreased at reduced pH levels compared to control conditions. These results suggest that future ocean acidification may lead to reduced primary polyp growth and delayed establishment of symbiosis. Stress exposure experiments using longer experimental time scales and lower levels of CO 2 concentrations than those used in this study are needed to establish the threshold of CO 2 emissions required to sustain coral reef ecosystems.

Ocean acidification is now recognized as a threat to marine ecosystems; however, the effect of ocean acidification on fertilization in marine organisms is still largely unknown. In this study, we focused on sperm flagellar motility in broadcast spawning reef invertebrates (a coral and a sea cucumber). Below pH 7.7, the pH predicted to occur within the next 100 years, sperm flagellar motility was seriously impaired in these organisms. Considering that sperm flagellar motility is indispensable for transporting the paternal haploid genome for fertilization, fertilization taking place in seawater may decline in the not too distant future. Urgent surveys are necessary for a better understanding of the physiological consequences of ocean acidification on sperm flagellar motility in a wide range of marine invertebrates.

We attempted to develop practical methods for coral reef rehabilitation, by means of the production of juveniles obtained from sexual reproduction, for a remote island where recruitment is limited. Adult corals (broodstocks) of Acropora tenuis were transported 1100 km from Okinotorishima, Japan's southernmost island in the Pacific, to a hatchery in Okinawa and maintained in land tanks. Eggs were obtained from captive spawning and the resulting larvae and juvenile corals were cultured under laboratory conditions. The present methodology enabled high survivorship and led to the successful mass production of coral juveniles. A total of 564 substrates with ~63 000 juvenile corals at the age of 10 mo were transported to the native reef. They were then transplanted in 3 experimental treatments, in order to evaluate effectiveness of protection by cages and/or hiding the juveniles under other substrates. Additionally, the effects of orientation on coral growth were tested by attaching the juveniles face down. The cages effectively protected the corals from predation and nibbling by fishes. The unshaded, upward facing corals in the cages steadily increased their coverage nearly 4-fold in ~2 yr.

Studying population genetics of deep‐sea animals helps us understand their history of habitat colonization and population divergence. Here, we report a population genetic study of the deep‐sea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) widely distributed in chemosynthesis‐based ecosystems in the Northwest Pacific. Three mitochondrial genes (i.e., atp6, cox1, and nad4) and 6,398 genomewide single nucleotide polymorphisms (SNPs) were obtained from 110 individuals from four hydrothermal vents and two methane seeps. When using the three mitochondrial genes, nearly no genetic differentiation was detected for B. platifrons in the Northwest Pacific. Nevertheless, when using SNP datasets, all individuals in the South China Sea (SCS) and three individuals in Sagami Bay (SB) together formed one genetic cluster that was distinct from the remaining individuals. Such genetic divergence indicated a genetic barrier to gene flow between the SCS and the open Northwest Pacific, resulting in the co‐occurrence of two cryptic semi‐isolated lineages. When using 125 outlier SNPs identified focusing on individuals in the Okinawa Trough (OT) and SB, a minor genetic subdivision was detected between individuals in the southern OT (S‐OT) and those in the middle OT (M‐OT) and SB. This result indicated that, although under the influence of the Kuroshio Current and the North Pacific Intermediate Water, subtle geographic barriers may exist between the S‐OT and the M‐OT. Introgression analyses based on these outlier SNPs revealed that Hatoma Knoll in the S‐OT represents a possible contact zone for individuals in the OT‐SB region. Furthermore, migration dynamic analyses uncovered stronger gene flow from Dai‐yon Yonaguni Knoll in the S‐OT to the other local populations, compared to the reverse directions. Taken together, the present study offered novel perspectives on the genetic connectivity of B. platifrons mussels, revealing the potential interaction of ocean currents and geographic barriers with adaption and reproductive isolation in shaping their migration patterns and genetic differentiation in the Northwest Pacific.

Human adenovirus type 53 (HAdV-53) has commonly been detected in samples from epidemic keratoconjunctivitis (EKC) patients in Japan since 1996. HAdV-53 is an intermediate virus, containing hexon-chimeric, penton base and fiber structures similar to HAdV-22 and -37, HAdV-37 and HAdV-8, respectively. HAdV-53-like intermediate strains were first isolated from EKC samples in Japan in the 1980s. Here, the complete genome sequences of three such HAdV-53-like intermediate strains (870006C, 880249C and 890357C) and four HAdV-53 strains were determined, and their relationships were analysed. The seven HAdV strains were classified into three groups, 870006C/880249C, 890357C and the four HAdV-53 strains, on the basis of phylogenetic analyses of the partial and complete genome sequences. HAdV strains within the same group showed the highest nucleotide identities (99.87-100.00 %). Like HAdV-53, the hexon loop 1 and 2 regions of 870006C, 880249C and 890357C showed the highest identity with HAdV-22. However, these strains did not show a hexon-chimeric structure similar to HAdV-22 and -37, or a penton base similar to HAdV-37. The fiber genes of 870006C and 880249C were identical to that of HAdV-37, but not HAdV-8. Thus, the three intermediate HAdVs isolated in the 1980s were similar to each other but not to HAdV-53. The recombination breakpoints were inferred by the Recombination Detection Program (RDP) using whole-genome sequences of these seven HAdV and of 12 HAdV-D strains from GenBank. HAdV-53 may have evolved from intermediate HAdVs circulating in the 1980s, and from HAdV-8, -22 and -37, by recombination of sections cut at the putative breakpoints.

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