Genomes of higher eukaryotes contain many transposable elements, which often localize within the transcribed regions of active genes. Although intragenic transposable elements can be silenced to form heterochromatin, the impact of intragenic heterochromatin on transcription and RNA processing remains largely unexplored. Here we show using a flowering plant, Arabidopsis, that full-length transcript formation over intragenic heterochromatin depends on a protein named IBM2 (Increase in Bonsai Methylation 2), which has a Bromo-Adjacent Homology domain and an RNA recognition motif. Mutation of ibm2 triggers premature termination of transcripts with 3 0 RNA processing around intragenic heterochromatin at loci including the H3K9 demethylase gene IBM1. The need for IBM2 is circumvented in variant alleles that lack the heterochromatic domain. Our results reveal a mechanism that masks deleterious effects of intragenic heterochromatin, providing evolutionary sources for genetic and epigenetic variations.

BiochemistryRole of steroid 11,6-hydroxylase and steroid 18-hydroxylase in the biosynthesis of glucocorticoids and mineralocorticoids in humans (cortisol (9) recently isolated aldosterone synthase cytochrome P-450 (P-450ado), which is induced in Na+-depleted K+-replete rat adrenal cortex (10,11), and demonstrated that rat P-450ado catalyzes three successive monooxygenation reactions of DOC to form aldosterone as a final product, whereas rat P-45011p does not substantially catalyze the reaction to form aldosterone. In regard to aldosterone biosynthesis in the human adrenal cortex, it has been postulated for a long time (12)(13)(14)

Foetomaternal alloimmune thrombocytopenia (FMAIT) occurs when maternal antibodies of an antigen-negative mother cause destruction of sensitized foetal platelets. In Caucasian populations, 6-12% of human platelet antigen (HPA)-1a-negative women develop anti-HPA-1a, and the incidence of clinically affected cases is estimated to be 10-20% of immunized women. This study was performed in order to elucidate the rate of maternal immunization, incidence of FMAIT and the likely outcome of the condition in Asians. Excluding two or more pregnancies during the period, serum samples from 24 630 pregnant women, mainly Japanese, were screened for antibodies against platelet alloantigens by means of mixed passive haemagglutination (MPHA) (Anti-HPA-MPHA, Olympus, Tokyo). Antibodies were detected in 0.91% (223/24 630) of the women's samples and the immunization rate was correlated with the number of pregnancies. Antibody specificity included anti-HPA-4b (49), anti-HPA-5a (three), anti-HPA-5b (168), anti-HPA-4b + 5b (one) and anti-Nak(a) (CD36) (two). No alloimmunization was observed within the HPA-1, HPA-2, HPA-3 or HPA-6 systems. Among HPA-4b- or HPA-5b-negative women, 24% or 14% estimated, respectively, had antibodies and 26% (10/38) or 10% (12/125) of neonates, respectively, born to these mothers developed thrombocytopenia. Two neonates born to mothers having anti-HPA-4b developed generalized purpura. No cases of intracranial bleeding or death due to FMAIT were recorded. Generalized purpura due to FMAIT occurs in one in 9359 (95% CI: 1 in 77 519-1 in 2591) pregnancies solely because of HPA-4b incompatibility.

In plants, epigenetic regulation is critical for silencing transposons and maintaining proper gene expression. However, its impact on the genome-wide transcription initiation landscape remains elusive. By conducting a genome-wide analysis of transcription start sites (TSSs) using cap analysis of gene expression (CAGE) sequencing, we show that thousands of TSSs are exclusively activated in various epigenetic mutants of Arabidopsis thaliana and referred to as cryptic TSSs. Many have not been identified in previous studies, of which up to 65% are contributed by transposons. They possess similar genetic features to regular TSSs and their activation is strongly associated with the ectopic recruitment of RNAPII machinery. The activation of cryptic TSSs significantly alters transcription of nearby TSSs, including those of genes important for development and stress responses. Our study, therefore, sheds light on the role of epigenetic regulation in maintaining proper gene functions in plants by suppressing transcription from cryptic TSSs.

Gonadal differentiation can take many forms in fish, ranging from gonochorism, where individuals directly develop as male or female and finally possess only testis or ovaries at sexual maturation, to hermaphroditism where the same individuals can produce mature male and female gametes at some time in their lives. Hermaphrodite fish are, thus, an excellent model for studying the plasticity of sex determination and differentiation in vertebrates. We have shown that sex steroids play a principal role in sex differentiation and sex change in fish. Our laboratory implements several fish models that undergo sex change from female to male or male to female or in both directions. In this review, we will briefly discuss recent advances in our understanding of the mechanism of sex change in coral reef fish.

BackgroundThe purpose of this study was to quantify the walking time and frequency of postural changes in daily life in patients with chronic obstructive pulmonary disease (COPD) using a new triaxial accelerometer system.MethodsTwenty-six elderly patients with stable COPD (age 76.8 ± 6.2 years; percent forced expiratory volume in one second [%FEV1] 52.9% ± 26.3%) and 20 age-matched elderly subjects (age 73.0 ± 4.2 years; %FEV1 124.0% ± 22.3%) participated in the study. The subjects’ time spent walking (slow, fast), standing, sitting, and lying down and the frequency of their postural changes (getting up, standing up) were assessed for 7 consecutive days using an Activity Monitoring And Evaluation System (A-MES™). We analyzed the relationships among walking times, frequency of postural changes, and physiologic factors in both COPD patients and controls.ResultsThe COPD patients’ total walking time, including slow (<2 km/hour) and fast (≥2 km/hour) walking, and their frequency of standing up were significantly lower than those of the age-matched controls (P < 0.01). The fast walking time in daily life was significantly correlated with the 6-minute walking distance, quadriceps femoris muscle force, and dyspnea (P < 0.01).ConclusionThese results suggest that both slow (<2 km/hour) and fast (≥2 km/hour) walking time and frequency of postural changes is significantly decreased in COPD patients compared with healthy elderly subjects. The data also suggest that the COPD patients’ different walking times in daily life are significantly correlated with exercise capacity and dyspnea. The 6-minute walking distance had the strongest correlation with fast walking time.

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Intronic regions of eukaryotic genomes accumulate many Transposable Elements (TEs). Intronic TEs often trigger the formation of transcriptionally repressive heterochromatin, even within transcription-permissive chromatin environments. Although TE-bearing introns are widely observed in eukaryotic genomes, their epigenetic states, impacts on gene regulation and function, and their contributions to genetic diversity and evolution, remain poorly understood. In this study, we investigated the genome-wide distribution of intronic TEs and their epigenetic states in the Oryza sativa genome, where TEs comprise 35% of the genome. We found that over 10% of rice genes contain intronic heterochromatin, most of which are associated with TEs and repetitive sequences. These heterochromatic introns are longer and highly enriched in promoter-proximal positions. On the other hand, introns also accumulate hypomethylated short TEs. Genes with heterochromatic introns are implicated in various biological functions. Transcription of genes bearing intronic heterochromatin is regulated by an epigenetic mechanism involving the conserved factor OsIBM2, mutation of which results in severe developmental and reproductive defects. Furthermore, we found that heterochromatic introns evolve rapidly compared to non-heterochromatic introns. Our study demonstrates that heterochromatin is a common epigenetic feature associated with actively transcribed genes in the rice genome.