The bulk of grass biomass potentially useful for cellulose-based biofuel production is the remains of secondary wall-containing sclerenchymatous fibers. Hence, it is important to uncover the ...molecular mechanisms underlying the regulation of secondary wall thickening in grass species. So far, little is known about the transcriptional regulatory switches responsible for the activation of the secondary wall biosynthetic program in grass species. Here, we report the roles of a group of rice and maize NAC and MYB transcription factors in the regulation of secondary wall biosynthesis. The rice and maize secondary wall-associated NACs (namely OsSWNs and ZmSWNs) were able to complement the Arabidopsis snd1 nst1 double mutant defective in secondary wall thickening. When overexpressed in Arabidopsis, OsSWNs and ZmSWNs were sufficient to activate a number of secondary wall-associated transcription factors and secondary wall biosynthetic genes, and concomitantly result in the ectopic deposition of cellulose, xylan and lignin. It was also found that the rice and maize MYB transcription factors, OsMYB46 and ZmMYB46, are functional orthologs of Arabidopsis MYB46/MYB83 and, when overexpressed in Arabidopsis, they were able to activate the entire secondary wall biosynthetic program. Furthermore, the promoters of OsMYB46 and ZmMYB46 contain secondary wall NAC-binding elements (SNBEs), which can be bound and activated by OsSWNs and ZmSWNs. Together, our results indicate that the rice and maize SWNs and MYB46 are master transcriptional activators of the secondary wall biosynthetic program and that OsSWNs and ZmSWNs activate their direct target genes through binding to the SNBE sites.
Abstract
Polycomb-group (PcG) proteins utilize epigenetic mechanisms to maintain the transcriptional silence of target genes. Recruitment of Drosophila PcG proteins to target genes requires the ...presence of a Polycomb Response Element (PRE). Some PcG target genes, including...
Polycomb-group (PcG) proteins are evolutionarily conserved epigenetic regulators whose primary function is to maintain the transcriptional repression of target genes. Recruitment of Drosophila melanogaster PcG proteins to target genes requires the presence of one or more Polycomb Response Elements (PREs). The functions or necessity for more than one PRE at a gene are not clear and individual PREs at some loci may have distinct regulatory roles. Various combinations of sequence-specific DNA-binding proteins are present at a given PRE, but only Pleiohomeotic (Pho) is present at all strong PREs. The giant (gt) locus has two PREs, a proximal PRE1 and a distal PRE2. During early embryonic development, Pho binds to PRE1 ∼30-min prior to stable binding to PRE2. This observation indicated a possible dependence of PRE2 on PRE1 for PcG recruitment; however, we find here that PRE2 recruits PcG proteins and maintains transcriptional repression independently of Pho binding to PRE1. Pho-like (Phol) is partially redundant with Pho during larval development and binds to the same DNA sequences in vitro. Although binding of Pho to PRE1 is dependent on the presence of consensus Pho-Phol-binding sites, Phol binding is less so and appears to play a minimal role in recruiting other PcG proteins to gt. Another PRE-binding protein, Sp1/Kruppel-like factor, is dependent on the presence of Pho for PRE1 binding. Further, we show that, in addition to silencing gene expression, PcG proteins dampen transcription of an active gene.
Physical activity confers many health benefits, but the underlying mechanisms require further exploration. In this pilot randomized controlled trial we tested the association between longitudinal ...measures of DNA methylation and changes in objective measures, including physical activity, weight loss, and C-reactive protein levels in community-dwelling women aged 55 to 70 years. We assessed DNA methylation from 20 healthy postmenopausal women, who did not have a mobility disability and allocated them to a group-based intervention, Everyday Activity Supports You, or a control group (monthly group-based health-related education sessions). The original randomized controlled trial was 6 months in duration and consisted of nine 2-h sessions that focused on reducing sedentary behaviour for the intervention group, or six 1-h sessions that focused on other topics for the control group. We collected peripheral blood mononuclear cells, both at baseline and 6 months later. Samples were processed using the Illumina 450k Methylation array to quantify DNA methylation at >485 000 CpG sites in the genome. There were no significant associations between DNA methylation and physical activity, but we did observe alterations at epigenetic modifications that correlated with change in percent body weight over a 6-month period at 12 genomic loci, 2 of which were located near the previously reported weight-associated genes RUNX3 and NAMPT. We also generated a potential epigenetic predictor of weight loss using baseline DNA methylation at 5 CpG sites. These exploratory findings suggest a potential biological link between body weight changes and epigenetic processes.
Celotno besedilo
Dostopno za:
DOBA, FSPLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Cancer Genome Atlas profiled 279 head and neck squamous cell carcinomas (HNSCCs) to provide a comprehensive landscape of somatic genomic alterations. Here we show that ...human-papillomavirus-associated tumours are dominated by helical domain mutations of the oncogene PIK3CA, novel alterations involving loss of TRAF3, and amplification of the cell cycle gene E2F1. Smoking-related HNSCCs demonstrate near universal loss-of-function TP53 mutations and CDKN2A inactivation with frequent copy number alterations including amplification of 3q26/28 and 11q13/22. A subgroup of oral cavity tumours with favourable clinical outcomes displayed infrequent copy number alterations in conjunction with activating mutations of HRAS or PIK3CA, coupled with inactivating mutations of CASP8, NOTCH1 and TP53. Other distinct subgroups contained loss-of-function alterations of the chromatin modifier NSD1, WNT pathway genes AJUBA and FAT1, and activation of oxidative stress factor NFE2L2, mainly in laryngeal tumours. Therapeutic candidate alterations were identified in most HNSCCs.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
The primary mission of any school system is to educate students. To achieve this goal, the school district must maintain a culture and environment where all students feel safe, nurtured, and valued ...and where order and civility are expected standards of behavior. Schools cannot allow unacceptable behavior to interfere with the school district’s primary mission. To this end, school districts adopt codes of conduct for expected behaviors and policies to address unacceptable behavior. In developing these policies, school boards must weigh the severity of the offense and the consequences of the punishment and the balance between individual and institutional rights and responsibilities. Out-of-school suspension and expulsion are the most severe consequences that a school district can impose for unacceptable behavior. Traditionally, these consequences have been reserved for offenses deemed especially severe or dangerous and/or for recalcitrant offenders. However, the implications and consequences of out-of-school suspension and expulsion and “zero-tolerance” are of such severity that their application and appropriateness for a developing child require periodic review. The indications and effectiveness of exclusionary discipline policies that demand automatic or rigorous application are increasingly questionable. The impact of these policies on offenders, other children, school districts, and communities is broad. Periodic scrutiny of policies should be placed not only on the need for a better understanding of the educational, emotional, and social impact of out-of-school suspension and expulsion on the individual student but also on the greater societal costs of such rigid policies. Pediatricians should be prepared to assist students and families affected by out-of-school suspension and expulsion and should be willing to guide school districts in their communities to find more effective and appropriate alternatives to exclusionary discipline policies for the developing child. A discussion of preventive strategies and alternatives to out-of-school suspension and expulsion, as well as recommendations for the role of the physician in matters of out-of-school suspension and expulsion are included. School-wide positive behavior support/positive behavior intervention and support is discussed as an effective alternative.
School Readiness High, Pamela C; and Committee on Early Childhood, Adoption, and Dependent Care and Council on School Health
Pediatrics (Evanston),
04/2008, Letnik:
121, Številka:
4
Journal Article
Recenzirano
School readiness includes the readiness of the individual child, the school's readiness for children, and the ability of the family and community to support optimal early child development. It is the ...responsibility of schools to be ready for all children at all levels of readiness. Children's readiness for kindergarten should become an outcome measure for community-based programs, rather than an exclusion criterion at the beginning of the formal educational experience. Our new knowledge of early brain and child development has revealed that modifiable factors in a child's early experience can greatly affect that child's learning trajectory. Many US children enter kindergarten with limitations in their social, emotional, cognitive, and physical development that might have been significantly diminished or eliminated through early identification of and attention to child and family needs. Pediatricians have a role in promoting school readiness for all children, beginning at birth, through their practices and advocacy. The American Academy of Pediatrics affords pediatricians many opportunities to promote the physical, social-emotional, and educational health of young children, with other advocacy groups. This technical report supports American Academy of Pediatrics policy statements "Quality Early Education and Child Care From Birth to Kindergarten" and "The Inappropriate Use of School 'Readiness' Tests."
School-based health centers (SBHCs) have become an important method of health care delivery for the youth of our nation. Although they only represent 1 aspect of a coordinated school health program ...approach, SBHCs have provided access to health care services for youth confronted with age, financial, cultural, and geographic barriers. A fundamental principle of SBHCs is to create an environment of service coordination and collaboration that addresses the health needs and well-being of youth with health disparities or poor access to health care services. Some pediatricians have concerns that these centers are in conflict with the primary care provider's medical home. This policy provides an overview of SBHCs and some of their documented benefits, addresses the issue of potential conflict with the medical home, and provides recommendations that support the integration and coordination of SBHCs and the pediatric medical home practice.
Expression of the Kaposi's sarcoma-associated herpesvirus (KSHV) cyclin D homolog, K cyclin, is thought to contribute to viral oncogenesis. We show that K cyclin expression in primary cells ...sensitizes to apoptosis and induces growth arrest, both of which are dependent on p53 but independent of E2F1 or p19
ARF
. DNA synthesis, but not cytokinesis, continues in K cyclin-expressing cells, leading to multinucleation and polyploidy. Such polyploid cells exhibit pronounced centrosome amplification and consequent aneuploidy. Our data suggest that K cyclin expression leads to cytokinesis defects and polyploidy, which activates p53. However, in the absence of p53, such cells survive and expand as an aneuploid population. Corroborating these findings, in vivo Eμ K cyclin expression cooperates with p53 loss in the induction of lymphomas.
Polycomb-group (PcG) proteins utilize epigenetic mechanisms to maintain the transcriptional silence of target genes. Recruitment of Drosophila PcG proteins to target genes requires the presence of a ...Polycomb Response Element (PRE). Some PcG target genes, including... Polycomb-group (PcG) proteins are evolutionarily conserved epigenetic regulators whose primary function is to maintain the transcriptional repression of target genes. Recruitment of Drosophila melanogaster PcG proteins to target genes requires the presence of one or more Polycomb Response Elements (PREs). The functions or necessity for more than one PRE at a gene are not clear and individual PREs at some loci may have distinct regulatory roles. Various combinations of sequence-specific DNA-binding proteins are present at a given PRE, but only Pleiohomeotic (Pho) is present at all strong PREs. The giant (gt) locus has two PREs, a proximal PRE1 and a distal PRE2. During early embryonic development, Pho binds to PRE1 ∼30-min prior to stable binding to PRE2. This observation indicated a possible dependence of PRE2 on PRE1 for PcG recruitment; however, we find here that PRE2 recruits PcG proteins and maintains transcriptional repression independently of Pho binding to PRE1. Pho-like (Phol) is partially redundant with Pho during larval development and binds to the same DNA sequences in vitro. Although binding of Pho to PRE1 is dependent on the presence of consensus Pho-Phol-binding sites, Phol binding is less so and appears to play a minimal role in recruiting other PcG proteins to gt. Another PRE-binding protein, Sp1/Kruppel-like factor, is dependent on the presence of Pho for PRE1 binding. Further, we show that, in addition to silencing gene expression, PcG proteins dampen transcription of an active gene.
Many children who take medications require them during the school day. This policy statement is designed to guide prescribing health care professionals, school physicians, and school health councils ...on the administration of medications to children at school. All districts and schools need to have policies and plans in place for safe, effective, and efficient administration of medications at school. Having full-time licensed registered nurses administering all routine and emergency medications in schools is the best situation. When a licensed registered nurse is not available, a licensed practical nurse may administer medications. When a nurse cannot administer medication in school, the American Academy of Pediatrics supports appropriate delegation of nursing services in the school setting. Delegation is a tool that may be used by the licensed registered school nurse to allow unlicensed assistive personnel to provide standardized, routine health services under the supervision of the nurse and on the basis of physician guidance and school nursing assessment of the unique needs of the individual child and the suitability of delegation of specific nursing tasks. Any delegation of nursing duties must be consistent with the requirements of state nurse practice acts, state regulations, and guidelines provided by professional nursing organizations. Long-term, emergency, and short-term medications; over-the-counter medications; alternative medications; and experimental drugs that are administered as part of a clinical trial are discussed in this statement. This statement has been endorsed by the American School Health Association.
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