The Arabidopsis MATERNAL EFFECT EMBRYO ARREST45 protein modulates maternal auxin biosynthesis and controls seed size by inducing AINTEGUMENTA.

Seed size is a major factor determining crop yields that is controlled through the coordinated development of maternal and zygotic tissues. Here, we identified Arabidopsis MATERNAL EFFECT EMBRYO ARREST45 (MEE45) as a B3 transcription factor that controls cell proliferation and maternally regulates seed size through its transcriptional activation of AINTEGUMENTA (ANT) and its downstream control of auxin biosynthesis in the ovule integument. After characterizing reduced seed and organ size phenotypes in mee45 mutants and finding that overexpression of MEE45 causes oversized seeds, we discovered that the MEE45 protein can bind to the promoter region of the ANT locus and positively regulate its transcription.

Integration of pluripotency pathways regulates stem cell maintenance in the shoot meristem.

In the shoot meristem, both WUSCHEL (WUS) and SHOOT MERISTEMLESS (STM), two transcription factors with overlapping spatiotemporal expression patterns, are essential for maintaining stem cells in an undifferentiated state. Despite their importance, it remains unclear how these two pathways are integrated to coordinate stem cell development. Here, we show that the WUS and STM pathways in converge through direct interaction between the WUS and STM proteins.

Genome-wide identification of imprinted genes in pigs and their different imprinting status compared with other mammals.

Genomic imprinting often results in parent-of-origin specific differential expression of maternally and paternally inherited alleles and plays an essential role in mammalian development and growth. Mammalian genomic imprinting has primarily been studied in mice and humans, with only limited information available for pigs. To systematically characterize this phenomenon and evaluate imprinting status between different species, we investigated imprinted genes on a genome-wide scale in pig brain tissues.

Determining population stratification and subgroup effects in association studies of rare genetic variants for nicotine dependence.

Background: Rare variants (minor allele frequency < 1% or 5 %) can help researchers to deal with the confounding issue of 'missing heritability' and have a proven role in dissecting the etiology for human diseases and complex traits.

Methods: We extended the combined multivariate and collapsing (CMC) and weighted sum statistic (WSS) methods and accounted for the effects of population stratification and subgroup effects using stratified analyses by the principal component analysis, named here as 'str-CMC' and 'str-WSS'. To evaluate the validity of the extended methods, we analyzed the Genetic Architecture of Smoking and Smoking Cessation database, which includes African Americans and European Americans genotyped on Illumina Human Omni2.

A non-threshold region-specific method for detecting rare variants in complex diseases.

A region-specific method, NTR (non-threshold rare) variant detection method, was developed-it does not use the threshold for defining rare variants and accounts for directions of effects. NTR also considers linkage disequilibrium within the region and accommodates common and rare variants simultaneously. NTR weighs variants according to minor allele frequency and odds ratio to combine the effects of common and rare variants on disease occurrence into a single score and provides a test statistic to assess the significance of the score.

[Chemical speciations of heavy metals and their risk assessment in agricultural soils in a coal mining area from Xingren County, Guizhou Province, China.].

In this study, total concentrations and chemical speciations of heavy metals (As, Cr, Pb, Zn, Cd, Hg, Cu and Ni) in 64 agricultural soil samples were determined to evaluate the level of contamination from a coal mining area in Xingren County, Guizhou Province. The single factor index, the Hkanson potential ecological risk index and the risk assessment code (RAC) were used for the evaluation of potential ecological and environmental risks in four main utilized types of soils (paddy soil, Coix lacryma-jobi soil, tobacco-growing soil and vegetable soil). The results demonstrated that the concentrations of heavy metals were significantly higher than their soil background values in Guizhou Province, with the exception of Zn.

Hepatitis B virus induces expression of cholesterol metabolism-related genes via TLR2 in HepG2 cells.

Aim: To investigate whether hepatitis B virus (HBV) exacerbates hepatic cholesterol accumulation, and explore the underlying mechanisms.

Methods: HepG2 cells were infected with adenovirus (Ad) containing 1.3-fold overlength HBV genome.