Arabidopsis HDA6 is required for freezing tolerance

The control of energy homeostasis within the hypothalamus is under the regulated control of homeostatic hormones, nutrients and the expression of neuropeptides that alter feeding behavior. Elevated levels of palmitate, a predominant saturated fatty acid in diet and fatty acid biosynthesis, alter cellular function. For instance, a key mechanism involved in the development of insulin resistance is lipotoxicity, through increased circulating saturated fatty acids. Although many studies have begun to determine the underlying mechanisms of lipotoxicity in peripheral tissues, little is known about the effects of excess lipids in the brain. To determine these mechanisms we used an immortalized, clonal, hypothalamic cell line, mHypoE-44, to demonstrate that palmitate directly alters the expression of molecular clock components, by increasing Bmal1 and Clock, or by decreasing Per2, and Rev-erbα, their mRNA levels and altering their rhythmic period within individual neurons. We found that these neurons endogenously express the orexigenic neuropeptides NPY and AgRP, thus we determined that palmitate administration alters the mRNA expression of these neuropeptides as well. Palmitate treatment causes a significant increase in NPY mRNA levels and significantly alters the phase of rhythmic expression. We explored the link between AMPK and the expression of neuropeptide Y using the AMPK inhibitor compound C and the AMP analog AICAR. AMPK inhibition decreased NPY mRNA. AICAR also elevated basal NPY, but prevented the palmitate-mediated increase in NPY mRNA levels. We postulate that this palmitate-mediated increase in NPY and AgRP synthesis may initiate a detrimental positive feedback loop leading to increased energy consumption.     

Acerogenin A, a natural compound isolated from Acer nikoense Maxim, stimulates osteoblast differentiation through bone morphogenetic protein action

We investigated the effects of acerogenin A, a natural compound isolated from Acer nikoense Maxim, on osteoblast differentiation by using osteoblastic cells. Acerogenin A stimulated the cell proliferation of MC3T3-E1 osteoblastic cells and RD-C6 osteoblastic cells (Runx2-deficient cell line). It also increased alkaline phosphatase activity in MC3T3-E1 and RD-C6 cells and calvarial osteoblastic cells isolated from the calvariae of newborn mice. Acerogenin A also increased the expression of mRNAs related to osteoblast differentiation, including Osteocalcin, Osterix and Runx2 in MC3T3-E1 cells and primary osteoblasts: it also stimulated Osteocalcin and Osterix mRNA expression in RD-C6 cells. The acerogenin A treatment for 3 days increased Bmp-2, Bmp-4, and Bmp-7 mRNA expression levels in MC3T3-E1 cells. Adding noggin, a BMP specific-antagonist, inhibited the acerogenin A-induced increase in the Osteocalcin, Osterix and Runx2 mRNA expression levels. These results indicated that acerogenin A stimulates osteoblast differentiation through BMP action, which is mediated by Runx2-dependent and Runx2-independent pathways.     

Differentiation in wild-type allele of the sd1 locus concerning culm length between indica and japonica subspecies of Oryza sativa (rice)

A dwarfing gene (allele) sd1-d has been intensively utilized to develop short-culm indica varieties in southeast Asia up to now. Before the first sd1-d-carrying variety IR8 was released, rice researchers had recognized the general tendency that culm length is higher in indica varieties than in temperate-japonica ones. Inter-subspecific difference of the tall (wild-type) allele SD1 at the sd1 locus was examined on the common genetic background, using five isogenic lines developed by substituting sd1-d of the recurrent parent IR36 by SD1s of two indica varieties, two temperate-japonica varieties and one tropical-japonica variety. The two indica -donor isogenic lines had longer culms than the three japonica-donor isogenic lines consistently in two different environmental conditions. Moreover, nonsynonymous single-nucleotide polymorphism between the two subspecies was detected at two sites in Exon 1 and Exon 3 of the sd1 locus. It is demonstrated that the inter-subspecific differentiation of SD1 contributes height difference between indica and japonica. The indica-originating and japonica-originating alleles at the sd1 locus were designated as SD1-in(t) and SD1-ja(t), respectively.     

Development of outdoor thermal index indicating universal and separate effects on human thermal comfort

The purpose of this study is to propose a new outdoor thermal index that simultaneously indicates universal and separate effects. The value indicating universal effect in this index consists of the summation of air temperature and the effective temperature differences by air velocity, longwave radiation, solar radiation, and humidity. This paper describes the theoretical construction of this newly derived index to compare with previous indices. The calculations of the new index are demonstrated using the observed data in order to explicitly indicate the specific features of the new index.     

Dietary astaxanthin inhibits colitis and colitis-associated colon carcinogenesis in mice via modulation of the inflammatory cytokines

Astaxanthin (AX) is one of the marine carotenoid pigments, which possess powerful biological antioxidant, anti-inflammatory and anti-cancer properties. The purpose of this study is to investigate possible inhibitory effect of AX against inflammation-related mouse colon carcinogenesis and dextran sulfate sodium (DSS)-induced colitis in male ICR mice. We conducted two different experiments. In the first experiment, we evaluated the effects of AX at three dose levels, 50, 100 and 200 ppm in diet, on colitis-associated colon carcinogenesis induced by azoxymethane (AOM)/DSS in mice. In the second, the effects of the AX (100 and 200 ppm) in diet on DSS-induced colitis were determined. We found that dietary AX significantly inhibited the occurrence of colonic mucosal ulcers, dysplastic crypts, and colonic adenocarcinoma at week 20. AX-feeding suppressed expression of inflammatory cytokines, including nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α and interleukin (IL)-1β, inhibited proliferation, and induced apoptosis in the colonic adenocarcinomas. Feeding with 200 ppm AX, but not 100 ppm, significantly inhibited the development of DSS-induced colitis. AX feeding (200 ppm in diet) also lowered the protein expression of NF-κB, and the mRNA expression of inflammatory cytokines, including IL-1β, IL-6, and cyclooxygenase (COX)-2. Our results suggest that the dietary AX suppresses the colitis and colitis-related colon carcinogenesis in mice, partly through inhibition of the expression of inflammatory cytokine and proliferation. Our findings suggest that AX is one of the candidates for prevention of colitis and inflammation-associated colon carcinogenesis in humans.     

Comparative analysis of mineralocorticoid receptor expression among vocal learners (Bengalese finch and budgerigar) and non-vocal learners (quail and ring dove) has implications for the evolution of avian vocal learning

Mineralocorticoid receptor is the receptor for corticosteroids such as corticosterone or aldosterone. Previously, we found that mineralocorticoid receptor was highly expressed in song nuclei of a songbird, Bengalese finch (Lonchura striata var. domestica). Here, to examine the relationship between mineralocorticoid receptor expression and avian vocal learning, we analyzed mineralocorticoid receptor expression in the developing brain of another vocal learner, budgerigar (Melopsittacus undulatus) and non-vocal learners, quail (Coturnix japonica) and ring dove (Streptopelia capicola). Mineralocorticoid receptor showed vocal control area-related expressions in budgerigars as Bengalese finches, whereas no such mineralocorticoid receptor expressions were seen in the telencephalon of non-vocal learners. Thus, these results suggest the possibility that mineralocorticoid receptor plays a role in vocal development of parrots as songbirds and that the acquisition of mineralocorticoid receptor expression is involved in the evolution of avian vocal learning.     

Arabidopsis RPT2a encoding the 26S proteasome subunit is required for various aspects of root meristem maintenance, and regulates gametogenesis redundantly with its homolog, RPT2b

The 26S proteasome plays fundamental roles in the degradation of short-lived regulatory proteins, thereby controlling diverse cellular processes. In Arabidopsis, the essential RPT2 subunit is encoded by two highly homologous genes: RPT2a and RPT2b. Currently, only RPT2a has been reported to regulate various developmental processes, including the maintenance of the root apical meristem (RAM), although the roles of RPT2a in the RAM are still obscure. Here, we analyzed the cell type-specific requirement for RPT2a. When RPT2a was expressed locally in the rpt2a mutant, pleiotropic defects in the RAM, such as cell death and distorted cellular organization, were rescued differently, suggesting that RPT2a regulates various specific activities, which converge to maintain the RAM. On the other hand, the homologous RPT2b was also expressed in meristems, and the expression of RPT2b protein under the control of the RPT2a promoter complemented the rpt2a RAM defects, although the rpt2b mutant showed no obvious defect in all developmental aspects we examined. These results show that RPT2b might work in the RAM, but is dispensable for RAM maintenance in the presence of RPT2a. In contrast, the rpt2a rpt2b double mutant was lethal in male and female gametophytes, suggesting that RPT2a and RPT2b are redundantly required for gametogenesis. Furthermore, we showed that similar meristematic and gametophytic defects were caused by mutations in other subunit genes, RPT5a and RPT5b, suggesting that proper activity of the proteasome, not an RPT2-specific function, is required. Taken together, our results suggest that RPT2a and RPT2b contribute differently to the proteasome activity required for each developmental context.     

Dietary adaptations of temperate primates: comparisons of Japanese and Barbary macaques

Habitat, diet and leaf chemistry are compared between Japanese and Barbary macaques to reveal the similarities and differences in dietary adaptations of temperate primates living at the eastern and western extremes of the genus Macaca. Tree species diversity and proportion of fleshy-fruited species are much higher in Japan than in North Africa. Both species spend considerable annual feeding time on leaves. Japanese macaques prefer fruits and seeds over leaves, and Barbary macaques prefer seeds. These characteristics are adaptive in temperate regions where fruit availability varies considerably with season, since animals can survive during the lean period by relying on leaf and other vegetative foods. The two species are different with respect to the higher consumption of herbs by Barbary macaques, and the leaves consumed contain high condensed and hydrolysable tannin for Barbary but not for Japanese macaques. Barbary macaques supplement less diverse tree foods with herbs. Because of the low species diversity and high tannin content of the dominant tree species, Barbary macaques may have developed the capacity to cope with tannin. This supports the idea that digestion of leaves is indispensable to survive in temperate regions where fruit and seed foods are not available for a prolonged period during each year.     

Shape of,and body direction in,huddles of Japanese macaques (<Emphasis Type="Italic">Macaca fuscata</Emphasis>) in Arashiyama,Japan

We studied huddles of Japanese macaques (Macaca fuscata) in the Arashiyama E troop at the “Arashiyama Monkey Park, Iwatayama” of Kyoto, central Japan. The macaques made physical contact with other individuals and formed huddles when the air was cold. The 99–101 adult females and 26–36 adult males in the study troop formed 345 huddles during 42 scan samples in the winter of 2001 and 376 huddles during 52 scan samples in the winter of 2002. The average size of huddles was 2.3 (range 2–7) individuals. Males huddled less frequently than females. Maternal kin-related dyads formed 2-female huddles more frequently than unrelated dyads. Choice of huddling partners might restrict the size of huddles. The most frequently observed 3 and 4-member huddles were triangular and diamond-shaped. Macaques usually huddled ventro–ventrally, ventro–laterally, and ventro–dorsally. A third individual frequently placed the ventral part of its body against the first individual and simultaneously put the lateral part of its body against the second individual, so that the 3 individuals formed a triangular huddle. This behaviour indicates that Japanese macaques choose their position and body direction in the huddle to reduce the area of body surface exposed to the air, thereby conserving body heat.