98 research outputs found
DNA methyltransferases are required to induce heterochromatic re-replication in Arabidopsis.
No full textThe relationship between epigenetic marks on chromatin and the regulation of DNA replication is poorly understood. Mutations of the H3K27 methyltransferase genes, Arabidopsis trithorax-related protein5 (ATXR5) and ATXR6, result in re-replication (repeated origin firing within the same cell cycle). Here we show that mutations that reduce DNA methylation act to suppress the re-replication phenotype of atxr5 atxr6 mutants. This suggests that DNA methylation, a mark enriched at the same heterochromatic regions that re-replicate in atxr5/6 mutants, is required for aberrant re-replication. In contrast, RNA sequencing analyses suggest that ATXR5/6 and DNA methylation cooperatively transcriptionally silence transposable elements (TEs). Hence our results suggest a complex relationship between ATXR5/6 and DNA methylation in the regulation of DNA replication and transcription of TEs
SRA-domain proteins required for DRM2-mediated de novo DNA methylation.
No full textDe novo DNA methylation and the maintenance of DNA methylation in asymmetrical sequence contexts is catalyzed by homologous proteins in plants (DRM2) and animals (DNMT3a/b). In plants, targeting of DRM2 depends on small interfering RNAs (siRNAs), although the molecular details are still unclear. Here, we show that two SRA-domain proteins (SUVH9 and SUVH2) are also essential for DRM2-mediated de novo and maintenance DNA methylation in Arabidopsis thaliana. At some loci, SUVH9 and SUVH2 act redundantly, while at other loci only SUVH2 is required, and this locus specificity correlates with the differing DNA-binding affinity of the SRA domains within SUVH9 and SUVH2. Specifically, SUVH9 preferentially binds methylated asymmetric sites, while SUVH2 preferentially binds methylated CG sites. The suvh9 and suvh2 mutations do not eliminate siRNAs, suggesting a role for SUVH9 and SUVH2 late in the RNA-directed DNA methylation pathway. With these new results, it is clear that SRA-domain proteins are involved in each of the three pathways leading to DNA methylation in Arabidopsis
TE studies in Japan: the fourth Japanese meeting on host–transposon interactions
No full textAbstract The fourth Japanese meeting entitled “Biological Function and Evolution through Interactions between Hosts and Transposable Elements (TEs)” was held on August 20–21, 2018 at the National Institute of Genetics (NIG), Mishima, Japan. The meeting was supported by NIG, and its objective was to bring together researchers who study the diverse roles of TEs in genome evolution, as well as host defense systems against TE mobility, such as chromatin modifications, small RNAs, and others. Here, we present the highlights of the talks given by 14 invited speakers. Organizers: Kenji Ichiyanagi (chief), Kuniaki Saito, and Tetsuji Kakutani
Heritable epigenetic mutation of a transposon-flanked Arabidopsis gene due to lack of the chromatin-remodeling factor DDM1
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Risky health behaviors and behavioral differences of the US youth: quasi-evidence with empirical study: policy implications
No full textThe focus of this paper is to examine the determinants and analyze the effects of risky health behaviors of alcohol and illicit drug use on social violence (drunken driving, riding in a car driven by a drunken driver, and not wearing seatbelts) among youth in the United States. Alcohol and illicit drug use usually lead to social violence as well as a reduction in health status and earnings. Although it is illegal to drink and drive in the U.S., forty-five percent of the traffic accidents among the age group of 14-18 are alcohol-related. Alcohol is a leading factor in deaths related to motor vehicle accidents.
This research defines use of alcohol, tobacco, cocaine, and other illicit drug use as risky health behavior. The use of some substances tend to precede and increase the risk of initiating habitual use of substances among the youth. The data used for this project is drawn from the 1992 and 2017 National Youth Risk Behavior Survey to examine the behavioral difference between two periods. The study examines the relationship between alcohol and illicit drug use and three types of violent behaviors: (1) drunken driving, (2) occupying a car driven by someone who has been drinking, and (3) not wearing seatbelts.
The results show that there is a positive relationship between the risky health behaviors of alcohol and illicit drug uses and social violence (drunken driving, riding in a car driven by a drunken driver, and not wearing seatbelts) among youth. The results suggest that binge drinking, smoking habits, as well as illicit drug use will contribute to the escalation of habitual, high-risk behaviors such as: drunken driving and not using seatbelts, among youth. The results also indicate that youth attitudes toward drunken driving will become more sensitive to multi-consumption habits as they get old. Controlling the consumption of alcohol and drug use at an early age is indeed an important factor in reducing drunken-driving behavior later. Drunken driving behavior is more likely to be a habitual behavior, and to reduce this behavior, access to alcohol and illicit drugs must be restricted among early teens.This audio recording was presented at the first annual Celebration of Undergraduate Research and Creative Activity while the author was an undergraduate student at Rutgers University-Camden
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