61 research outputs found
Inner centromere formation requires hMis14, a trident kinetochore protein that specifically recruits HP1 to human chromosomes
hMis14 and HP1 depend on each other to localize to the kinetochore and inner centromere, respectively
Population genetic structure ofYamato-sllijimi clam in Lake Sbinji, Japan
Yamato-shijimiclam Corbicula japonica is the best-known bivalve inhabiting ln brackish estuaries and lakes around Japan and one of the most commercially important species in inland fisheries. Althoughthe amotmt of C japonica from Lake Shinji has accotmted for the large part of the domestic catch, itsamolmt has dramatically fallen in recent years・ This study was conducted to verifythe genetic structtue and reproduction mechanism of C・ japonica, both of which are essential to its stock management in Lake Shinji. Weanalyzed sequence polymorphism of the 588 bp portion ofthemitochondrial DNA cytochrome oxidase subunit I (Col) gene to determinethe population genetic structure of C・ japonica in Lake Shinji・Among a total of 177 C・ japonica specimens collected from 4 colonies, 37 haplotypes were obtained, and 2 major haplotypes were apparent withrelatively highabtmdance in all colonies・ Well correspondingmismatch distributions along the Col gene were determined for the data sets of the individual colonies, and the pairwise population estimates FsT among the individual colonies were also generally low, Such small genetic differentiation of C japonica is derived kom highgeneflow in Lake Shinji, and this could be caused by a lake-wide dispersion of its larvae mediated by the water movements・Article信州大学山地水環境教育研究センター研究報告 6: 115-124(2010)departmental bulletin pape
Effects of fermented brown rice on the intestinal environments in healthy adult
Purpose : The aim of this study is to investigate the prebiotic effects of brown
rice fermented by Aspergillus oryzae (FBRA) on the intestinal environment in vitro and
in healthy adults. Methods : Fresh fecal slurries from six healthy adults were incubated
with FBRA to confirm prebiotic potentials of FBRA. Another thirty-six healthy adults
were randomly allocated to 2 groups for the clinical study. Subjects consumed 21.0 g/day
of either FBRA or control food for 2 weeks, followed by a 12-week intermission and then
2-week ingestion vice versa. Main outcome measures were bifidobacterial numbers and
organic acid concentration in feces. Sub outcome measures were fecal microbiota, fecal
environments and bowel function. Results : Incubation of fecal slurries with FBRA in
vitro resulted in increased organic acids with individual-specific patterns. Bifidobacterial
numbers were increased during incubation. In the clinical study, all participants
safely completed this study. FBRA had little effect on fecal number of bifidobacteria, concentrations
of organic acids or putrefactive metabolites, fecal pH, or fecal microbiota.
Conclusion : FBRA has the potentials as a prebiotic, however, we could not detect its
effects on the intestinal environment in vivo. The results in a clinical study indicated that
FBRA could be safely used for healthy adults
A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators.
Giant viruses are remarkable for their large genomes, often rivaling those of small bacteria, and for having genes thought exclusive to cellular life. Most isolated to date infect nonmarine protists, leaving their strategies and prevalence in marine environments largely unknown. Using eukaryotic single-cell metagenomics in the Pacific, we discovered a Mimiviridae lineage of giant viruses, which infects choanoflagellates, widespread protistan predators related to metazoans. The ChoanoVirus genomes are the largest yet from pelagic ecosystems, with 442 of 862 predicted proteins lacking known homologs. They are enriched in enzymes for modifying organic compounds, including degradation of chitin, an abundant polysaccharide in oceans, and they encode 3 divergent type-1 rhodopsins (VirR) with distinct evolutionary histories from those that capture sunlight in cellular organisms. One (VirRDTS) is similar to the only other putative rhodopsin from a virus (PgV) with a known host (a marine alga). Unlike the algal virus, ChoanoViruses encode the entire pigment biosynthesis pathway and cleavage enzyme for producing the required chromophore, retinal. We demonstrate that the rhodopsin shared by ChoanoViruses and PgV binds retinal and pumps protons. Moreover, our 1.65-Å resolved VirRDTS crystal structure and mutational analyses exposed differences from previously characterized type-1 rhodopsins, all of which come from cellular organisms. Multiple VirR types are present in metagenomes from across surface oceans, where they are correlated with and nearly as abundant as a canonical marker gene from Mimiviridae Our findings indicate that light-dependent energy transfer systems are likely common components of giant viruses of photosynthetic and phagotrophic unicellular marine eukaryotes
A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators
Significance:
Although viruses are well-characterized regulators of eukaryotic algae, little is known about those infecting unicellular predators in oceans. We report the largest marine virus genome yet discovered, found in a wild predatory choanoflagellate sorted away from other Pacific microbes and pursued using integration of cultivation-independent and laboratory methods. The giant virus encodes nearly 900 proteins, many unlike known proteins, others related to cellular metabolism and organic matter degradation, and 3 type-1 rhodopsins. The viral rhodopsin that is most abundant in ocean metagenomes, and also present in an algal virus, pumps protons when illuminated, akin to cellular rhodopsins that generate a proton-motive force. Giant viruses likely provision multiple host species with photoheterotrophic capacities, including predatory unicellular relatives of animals.
Abstract:
Giant viruses are remarkable for their large genomes, often rivaling those of small bacteria, and for having genes thought exclusive to cellular life. Most isolated to date infect nonmarine protists, leaving their strategies and prevalence in marine environments largely unknown. Using eukaryotic single-cell metagenomics in the Pacific, we discovered a Mimiviridae lineage of giant viruses, which infects choanoflagellates, widespread protistan predators related to metazoans. The ChoanoVirus genomes are the largest yet from pelagic ecosystems, with 442 of 862 predicted proteins lacking known homologs. They are enriched in enzymes for modifying organic compounds, including degradation of chitin, an abundant polysaccharide in oceans, and they encode 3 divergent type-1 rhodopsins (VirR) with distinct evolutionary histories from those that capture sunlight in cellular organisms. One (VirRDTS) is similar to the only other putative rhodopsin from a virus (PgV) with a known host (a marine alga). Unlike the algal virus, ChoanoViruses encode the entire pigment biosynthesis pathway and cleavage enzyme for producing the required chromophore, retinal. We demonstrate that the rhodopsin shared by ChoanoViruses and PgV binds retinal and pumps protons. Moreover, our 1.65-Å resolved VirRDTS crystal structure and mutational analyses exposed differences from previously characterized type-1 rhodopsins, all of which come from cellular organisms. Multiple VirR types are present in metagenomes from across surface oceans, where they are correlated with and nearly as abundant as a canonical marker gene from Mimiviridae. Our findings indicate that light-dependent energy transfer systems are likely common components of giant viruses of photosynthetic and phagotrophic unicellular marine eukaryotes
Central control of bone remodeling by neuromidin U.
Bone remodeling, the function affected in osteoporosis, the most common of bone diseases, comprises two phases: bone formation by matrix-producing osteoblasts 1 and bone resorption by osteoclasts 2 . The demonstration that the anorexigenic hormone leptin 3-5 inhibits bone formation through a hypothalamic relay Bone mass is maintained at a constant level between puberty and menopause by a succession of bone-resorption and bone-formation phases NMU is a small peptide produced by nerve cells in the submucosal and myenteric plexuses in the small intestine, and also by structures in the brain, including the dorsomedial nucleus of the hypothalamus 9 . It is generally assumed that NMU acts as a neuropeptide to regulate various aspects of physiology, including appetite, stress response and SNS activation 9 . Indeed, NMU-deficient (Nmu -/-) mice develop obesity due to increased food intake and reduced locomotor activity that is believed, at least in part, to be leptin independent 8 . In addition, expression of NMU is diminished in leptin-deficient (Lep ob ) mice 18 , but can be induced in these mice by leptin treatment When assessed at 3 and 6 months of age, both male and female Nmu -/-mice showed a high bone mass phenotype as compared to the wild type (WT), with male mice more severely affected than female mic
- …