Expression and genome-wide analysis of the xylogen-type gene family

In higher plants, many extracellular proteins are involved in developmental processes, including cell-cell signaling and cell wall construction. Xylogen is an extracellular arabinogalactan protein (AGP) isolated from Zinnia elegans xylogenic culture medium, which promotes xylem cell differentiation. Xylogen has a unique structure, containing a non-specific lipid transfer protein (nsLTP) domain and AGP domains. We searched for xylogen-type genes in the genomes of land plants, including Arabidopsis thaliana, to further our knowledge of xylogen-type genes as functional extracellular proteins in plants. We found that many xylogen-type genes, including 13 Arabidopsis genes, comprise a gene family in land plants, including Populus trichocarpa, Vitis vinifera, Lotus japonicus, Oryza sativa, Selaginella moellendorffii and Physcomitrella patens. The genes shared an N-terminal signal peptide sequence, a distinct nsLTP domain, one or more AGP domains and a glycosylphosphatidylinositol (GPI)-anchored sequence. We analyzed transgenic plants harboring promoter::GUS (β-glucuronidase) constructs to test expression of the 13 Arabidopsis xylogen-type genes, and detected a diversity of gene family members with related expression patterns. AtXYP2 was the best candidate as the Arabidopsis counterpart of the Zinnia xylogen gene. We observed two distinct expression patterns for several genes, with some anther specific and others preferentially expressed in the endodermis/pericycle. We conclude that xylogen-type genes, which may have diverse functions, form a novel chimeric AGP gene family with a distinct nsLTP domain.     

Triglyceride levels are ethnic-specifically associated with an index of stearoyl-CoA desaturase activity and n-3 PUFA levels in Asians

Accumulated evidence suggests that hypertriglyceridemia (HTG) is independently associated with an increased incidence of cardiovascular disease. The hypotriglyceridemic effects of n-3 PUFAs have been confirmed in Caucasians, but the effect in Asians is less clear. Recent evidence indicates that stearoyl-CoA desaturase (SCD) activity induced with high-carbohydrate diets increases plasma triglyceride levels. We investigated the relationship between triglyceride levels and the ratio of plasma oleic acid to stearic acid (the 18:1/18:0 ratio), a plasma marker of SCD activity, and n-3 PUFAs in 411 Japanese, 418 Korean, and 251 Mongolian adults. The Japanese and Koreans had higher values for triglyceride than their Mongolian counterparts, despite lower body mass index values for the Japanese and Koreans. The Japanese and Koreans ate fish more frequently and had remarkably higher values for n-3 PUFAs than did the Mongolians. Multiple regression analysis showed that triglyceride levels had a great magnitude of correlation with the increases in 18:1/18:0 ratio for the Japanese and Mongolians, and n-3 PUFAs remained significant for the Mongolians. HTG is ethnicity-specifically associated with an increase in the 18:1/18:0 ratio and a decrease in n-3 PUFA in plasma for Japanese, Koreans, and Mongolians.     

Nematode Homologue of PQBP1, a Mental Retardation Causative Gene,Is Involved in Lipid Metabolism

Background

PQBP1 is a causative gene for X-linked mental retardation (MR) whose patients frequently show lean body. C. elegans has a strictly conserved homologue gene of PQBP1, T21D12.3.

Methodology and Principal Findings

We generated Venus-transgenic and T21D12.3-mutant nematodes to analyze developmental expression patterns and in vivo functions of the nematode PQBP1 homologue protein (pqbp-1.1). During development, pqbp-1.1 is expressed from cell proliferation stage to larva stage. In larva, intestinal cells show the highest expression of pqbp-1.1, while it decreases in adult worms. The mutants of pqbp-1.1 show a decrease of the lipid content in intestinal cells. Especially, incorporation of fatty acid into triglyceride is impaired. ShRNA-mediated repression of PQBP1 also leads to reduction of lipid content in mammalian primary white adipocytes.

Conclusion/ Significance

These results suggest that pqbp-1.1 is involved in lipid metabolism of intestinal cells. Dysfunction of lipid metabolism might underlie lean body, one of the most frequent symptoms associating with PQBP1-linked MR patients.     

CYP1A2 polymorphism (C > A at position -163) in Ovambos, Koreans and Mongolians

Cytochrome P450 1A2 (CYP1A2) plays an important role in metabolizing drugs and xenobiotics, and is a possible participant in the development of several human diseases. Recent studies have shown that genetic polymorphism of -163 C > A single nucleotide mutation of CYP1A2 increases the risk of myocardial infarction and modulates CYP1A2 activity. In this study, we investigated the frequency of the -163 C > A mutation in Ovambos (n = 177), Koreans (n = 250) and Mongolians (n = 153) and compared our results with other studies. Detection of this single nucleotide polymorphism was by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). The frequencies of mutation (CYP1A2*-163A) in the Ovambos, Koreans and Mongolians were 0.46, 0.32 and 0.21, respectively. Ovambos showed a relatively higher frequency of mutation, similar to that of Tanzanians, while the Mongolians showed the lowest frequency of all study groups, including those from previous studies. This study is the first to investigate the distribution of the CYP1A2 (-163 C > A single nucleotide polymorphism) mutant allele in Ovambo, Korean and Mongolian populations.     

Effect of Environmental and Lifestyle Factors on Hypertension: Shimane COHRE Study

Background

In recent years there has been increasing evidence of an association between residential remoteness and hypertension (HTN); however, no study has examined the effects of residential remoteness-lifestyle associations on HTN. The objective of this study was to evaluate the effects of residential remoteness, as measured by road network distance and elevation, and lifestyle associations, including access to daily products as a measure of car use, on HTN in a rural region in Japan.

Method

This is a cross-sectional population based study. We analyzed data from the Shimane COHRE study conducted from 2006 to 2009 in the rural mountainous regions of Japan. After excluding missing data, we conducted a logistic regression analysis of the data for 1,348 individuals and examined the effects of residential remoteness and lifestyle associations, including road network distance, elevation and access to daily products as a measure of car use, on the prevalence of HTN.

Principal Findings

In participants without access to car use, the odds ratios for self-reported HTN (i.e. taking antihypertensive medication) were significantly increased in those living in moderate (odds ratio (OR): 2.21, 95% confidence interval (CI): 1.19–4.08) and far (OR: 2.55, 95% CI: 1.00–6.51) road distances, whereas there were no significant associations in participants with access to car use. There were no significant associations between elevation and HTN for participants either with or without access to car transportation.

Conclusions

Our findings show that specific residential remoteness-hypertension associations vary according to access to daily products as a measure of car use in a rural mountainous area of Japan. These results advance the understanding and importance of considering residential environment, “where people live,” in establishing health policy.     

Selective autophagy regulates insertional mutagenesis by the Ty1 retrotransposon in Saccharomyces cerevisiae

Macroautophagy (autophagy) is a bulk degradation system for cytoplasmic components and is ubiquitously found in eukaryotic cells. Autophagy is induced under starvation conditions and plays a cytoprotective role by degrading unwanted cytoplasmic materials. The Ty1 transposon, a member of the Ty1/copia superfamily, is the most abundant retrotransposon in the yeast Saccharomyces cerevisiae and acts to introduce mutations in the host genome via Ty1 virus-like particles (VLPs) localized in the cytoplasm. Here we show that selective autophagy downregulates Ty1 transposition by eliminating Ty1 VLPs from the cytoplasm under nutrient-limited conditions. Ty1 VLPs are targeted to autophagosomes by an interaction with Atg19. We propose that selective autophagy safeguards genome integrity against excessive insertional mutagenesis caused during nutrient starvation by transposable elements in eukaryotic cells.     

Francisella sp. (Family Francisellaceae) causing mortality in Norwegian cod (Gadus morhua) farming

In 2004, a new disease was detected in cod (Gadus morhua) in western Norway. Affected cod had white granulomas in the visceral organs and skin. A species of Francisella was isolated on blood agar plates from moribund cod. The bacterium could be grown at temperatures ranging from 6 to 22°C, but did not grow at 37°C. Challenge experiments showed that Francisella sp. was the cause for the new disease. The 16S rDNA gene sequence from Francisella sp. showed 99.17% similarity to F. philomiragia, and the 16S–23S ribosomal RNA intergenic spacer (249 nt), shows a similarity with that from Francisella isolated from tilapia and F. tularensis of 96.8 and 35.9%, respectively. The 23S sequence is more similar to F. tularensis, 97.7% (2,862 nt), compared to the tilapia isolate 96.8% (2,131 nt). The partial putative outer membrane protein (FopA) sequence (781 nt) from Francisella sp. shows a similarity with that from F. tularensis and F. philomiragia of 77.3 and 98.2%, respectively. Based on sequence data, culturing temperatures and pathogenicity for cod, it is suggested that this Francisella sp. from cod could be a new species of Francisella, Family Francisellaceae.