Differential dynamics of histone H3 methylation at positions K4 and K9 in the mouse zygote

BACKGROUND: In the mouse zygote the paternal genome undergoes dramatic structural and epigenetic changes. Chromosomes are decondensed, protamines replaced by histones and DNA is rapidly and actively demethylated. The epigenetic asymmetry between parental genomes remains at least until the 2-cell stage suggesting functional differences between paternal and maternal genomes during early cleavage stages. RESULTS: Here we analyzed the timing of histone deposition on the paternal pronucleus and the dynamics of histone H3 methylation (H3/K4mono-, H3/K4tri- and H3/K9di-methylation) immediately after fertilization. Whereas maternal chromatin maintains all types of histone H3 methylation throughout the zygotic development, paternal chromosomes acquire new and unmodified histones shortly after fertilization. In the following hours we observe a gradual increase in H3/K4mono-methylation whereas H3/K4tri-methylation is not present before latest pronuclear stages. Histone H3/K9di-methylation is completely absent from the paternal pronucleus, including metaphase chromosomes of the first mitotic stage. CONCLUSION: Parallel to the epigenetic asymmetry in DNA methylation, chromatin modifications are also different between both parental genomes in the very first hours post fertilization. Whereas methylation at H3/K4 gradually becomes similar between both genomes, H3/K9 methylation remains asymmetric

Tindak Tutur Direktif Dalam Novel Pukat Karya Tere-liye

This article was written based on (a) to describe the type of directive speech acts, (b) the strategy told the directive speech act, (c) the context of the use of directive speech acts, and (d) the effect of the use of linguistic politeness strategies recalled toin the novelPukat created by Tere-Liye.The data of this study is the speech acts of the figures contained in the novel Pukat created by Tere-Liye.The data source of this research is the novelPukat created by Tere-Liye.Data collected by reading and noting directive speech acts contained therein. Data were analyzed with the following steps: (1) identify the data and classifies data based on type, recalled strategy, context, and tells of the effects of linguistic politeness strategies in the directive speech act, (2) connecting the data with the data of the other, (3 ) conducted a study of data inference.The findings of this study are as follows. First, there are 5 types of directive speech acts, that is telling, asking, advising, challenging, and suggest. Second, there are 3 strategies recalled, that tells directly without further ado, instantly recalled with niceties positive politeness, recalled instantly with niceties negative politeness. Third, the strategy of direct recalled without further ado tends to be used in the context of the directive speech act hearer smaller, intimate, and speech do both. Fourth, the use of recalled strategy directly without further ado hearer in the context of smaller, intimate, and the speech made ​​two decent effect

Selective impairment of methylation maintenance is the major cause of DNA methylation reprogramming in the early embryo

DNA methylomes are extensively reprogrammed during mouse pre-implantation and early germ cell development. The main feature of this reprogramming is a genome-wide decrease in 5-methylcytosine (5mC). Standard high-resolution single-stranded bisulfite sequencing techniques do not allow discrimination of the underlying passive (replication-dependent) or active enzymatic mechanisms of 5mC loss. We approached this problem by generating high-resolution deep hairpin bisulfite sequencing (DHBS) maps, allowing us to follow the patterns of symmetric DNA methylation at CpGs dyads on both DNA strands over single replications.We compared DHBS maps of repetitive elements in the developing zygote, the early embryo, and primordial germ cells (PGCs) at defined stages of development. In the zygote, we observed distinct effects in paternal and maternal chromosomes. A significant loss of paternal DNA methylation was linked to replication and to an increase in continuous and dispersed hemimethylated CpG dyad patterns. Overall methylation levels at maternal copies remained largely unchanged, but showed an increased level of dispersed hemi-methylated CpG dyads. After the first cell cycle, the combined DHBS patterns of paternal and maternal chromosomes remained unchanged over the next three cell divisions. By contrast, in PGCs the DNA demethylation process was continuous, as seen by a consistent decrease in fully methylated CpG dyads over consecutive cell divisions.The main driver of DNA demethylation in germ cells and in the zygote is partial impairment of maintenance of symmetric DNA methylation at CpG dyads. In the embryo, this passive demethylation is restricted to the first cell division, whereas it continues over several cell divisions in germ cells. The dispersed patterns of CpG dyads in the early-cleavage embryo suggest a continuous partial (and to a low extent active) loss of methylation apparently compensated for by selective de novo methylation. We conclude that a combination of passive and active demethylation events counteracted by de novo methylation are involved in the distinct reprogramming dynamics of DNA methylomes in the zygote, the early embryo, and PGCs

Evidence for conserved DNA and histone H3 methylation reprogramming in mouse, bovine and rabbit zygotes

<p>Abstract</p> <p>Background</p> <p>In mammals the parental genomes are epigenetically reprogrammed after fertilization. This reprogramming includes a rapid demethylation of the paternal (sperm-derived) chromosomes prior to DNA replication in zygotes. Such active DNA demethylation in the zygote has been documented for several mammalian species, including mouse, rat, pig, human and cow, but questioned to occur in rabbit.</p> <p>Results</p> <p>When comparing immunohistochemical patterns of antibodies against 5-methyl-cytosine, H3K4me3 and H3K9me2 modifications we observe similar pronuclear distribution and dynamics in mouse, bovine and rabbit zygotes. In rabbit DNA demethylation of the paternal chromosomes occurs at slightly advanced pronuclear stages. We also show that the rabbit oocyte rapidly demethylates DNA of donor fibroblast after nuclear transfer.</p> <p>Conclusion</p> <p>Our data reveal that major events of epigenetic reprogramming during pronuclear maturation, including mechanisms of active DNA demethylation, are apparently conserved among mammalian species.</p

Influence of surgical correction of inguinal hernia and hydrocele on testicular blood flow in children

Inguinal hernia and hydrocele affect the blood circulation of the testicle. Surgical trauma may change testicular blood flow. Objective. To study changes in blood flow parameters in children with pathology of the processus vaginalis, requiring surgical correction, using the analysis of ultrasound data. Materials and methods. We observed 87 boys from 3 to 17 years old, operated for congenital inguinal hernia and hydrocele. As a control group we examined 34 boys without pathology of the reproductive system. Patients held Doppler ultrasound the day before surgery, at 1 and 7 days after. Peak systolic flow velocity, end-diastolic flow velocity and resistance index were studied. Results. The resistance index on the affected side was higher compared with the control group before operation (p<0,05). The values of peak systolic and end diastolic blood flow velocities were lower than in the comparison group (p<0,05). Resistance index increased compared with preoperative period 1 day after surgery (p<0,05). Values of flow velocity parameters decreased to 4-9 % compared to values before the operation. The resistance index decreased (p<0,05) to near baseline figures a week after the operation. Peak systolic and end-diastolic flow velocity raised to 15-21 % compared to the preoperative period. However, the intensity of the blood flow in the affected testicle remained lower than in the control group (p<0,05). Conclusions. The blood flow of affected testicle in children with inguinal hernia and hydrocele is initially decreased. Early postoperative period is characterized by intensification of testicular parenchyma’s ischemia. Postoperative blood flow in the affected testicle is improved a week after surgery, but the lack of blood supply to the testicle is retained

Prolonged drainage of the lower urinary tract in the treatment of refluxing megaureter in children

The main purpose. To substantiate the need for conservative therapy as the first stage of treatment refluxing megoureter in newborns and infants. Materials and methods. Analyzed result s of treatment 19 children (25 ureters) with different levels of the disease. The evaluation criteria were the ultrasonographic researchers, determining the degree of dilatation of the ureters, the cup-and-pelvis system and the thickness of the kidney parenchyma, as well as the presence of an urinary tract infection. Treatment based on prolonged drainage and lower urinary tract catheter Folleya (up to 1 month), with the interleave instrument natural urination (also up to 1 month, or until the secondary acute pyelonephritis). Medication support was in an antibiotic therapy, taking into account with the sensitivity of microflora and preventive treatment uroseptics. There were regularly monitoring the degree of activity of the secondary flow of pyelonephritis and excretory function of the kidney. Excretory urography and cystography used in suspected degradation of structural parameters and renal function. Indications for surgical treatment were indestructible inflammatory process within one month, the progression of dilatation of the ureters and renal pelvis system, thinning and disruption of parenchymal renal excretory function. Results. In 6 (31,6%) of children to the age of 2 years were revealed a complete disappearance of dilatation of the ureter. In 3 cases of them survived vesicoureteral reflux 1- 2 degrees without renal impairment and without bladder syndrome, which can be considered as a positive treatment outcome. Conclusion. Treatment the newborns and infants with refluxing megaureter should begin with conservative therapy, including prolonged drainage of the lower urinary tract

Selective impairment of methylation maintenance is the major cause of DNA methylation reprogramming in the early embryo

BACKGROUND: DNA methylomes are extensively reprogrammed during mouse pre-implantation and early germ cell development. The main feature of this reprogramming is a genome-wide decrease in 5-methylcytosine (5mC). Standard high-resolution single-stranded bisulfite sequencing techniques do not allow discrimination of the underlying passive (replication-dependent) or active enzymatic mechanisms of 5mC loss. We approached this problem by generating high-resolution deep hairpin bisulfite sequencing (DHBS) maps, allowing us to follow the patterns of symmetric DNA methylation at CpGs dyads on both DNA strands over single replications. RESULTS: We compared DHBS maps of repetitive elements in the developing zygote, the early embryo, and primordial germ cells (PGCs) at defined stages of development. In the zygote, we observed distinct effects in paternal and maternal chromosomes. A significant loss of paternal DNA methylation was linked to replication and to an increase in continuous and dispersed hemimethylated CpG dyad patterns. Overall methylation levels at maternal copies remained largely unchanged, but showed an increased level of dispersed hemi-methylated CpG dyads. After the first cell cycle, the combined DHBS patterns of paternal and maternal chromosomes remained unchanged over the next three cell divisions. By contrast, in PGCs the DNA demethylation process was continuous, as seen by a consistent decrease in fully methylated CpG dyads over consecutive cell divisions. CONCLUSIONS: The main driver of DNA demethylation in germ cells and in the zygote is partial impairment of maintenance of symmetric DNA methylation at CpG dyads. In the embryo, this passive demethylation is restricted to the first cell division, whereas it continues over several cell divisions in germ cells. The dispersed patterns of CpG dyads in the early-cleavage embryo suggest a continuous partial (and to a low extent active) loss of methylation apparently compensated for by selective de novo methylation. We conclude that a combination of passive and active demethylation events counteracted by de novo methylation are involved in the distinct reprogramming dynamics of DNA methylomes in the zygote, the early embryo, and PGCs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1756-8935-8-1) contains supplementary material, which is available to authorized users

Compreendendo a imagem de uma cobra em diferentes imagens linguísticas e culturais do mundo

O artigo discute expressões idiomáticas que funcionam na língua de diferentes povos (Rússia, China etc.). A análise das unidades fraseológicas ajuda a entender a visão de mundo e a percepção da realidade circundante por uma determinada nação. A originalidade da imagem linguística do mundo é formada com base na língua de cada nação separadamente, e é o estudo das expressões idiomáticas que contribui para a cognição dessa imagem linguística do mundo de um determinado povo. Devido ao fato de que a vida humana e o mundo animal estão intimamente interligados e interrelacionados, é o estudo dos zoônimos usados em unidades fraseológicas que ajuda a explorar e entender melhor a cultura de diferentes povos. Além disso, são os zoônimos os mais utilizados no fundo fraseológico de qualquer língua, já que o folclore (provérbios, ditados) é a principal fonte que reabastece as línguas com expressões idiomáticas. Este artigo examina a imagem de uma cobra, que funciona nas unidades fraseológicas de diferentes povos, a análise dessa imagem permitiu revelar que, na imagem linguística do mundo, diferentes povos formaram uma atitude ambivalente em relação a essa imagem

DNA methylation dynamics of the human preimplantation embryo

In mammals, cytosine methylation is predominantly restricted to CpG dinucleotides and stably distributed across the genome, with local, cell type-specific regulation directed by DNA binding factors1-3. This comparatively static landscape dramatically contrasts the events of fertilization, where the paternal genome is globally reprogrammed. Paternal genome demethylation includes the majority of CpGs, though methylation is maintained at several notable features4-7. While these dynamics have been extensively characterized in the mouse, only limited observations are available in other mammals, and direct measurements are required to understand the extent to which early embryonic landscapes are conserved8-10. We present genome-scale DNA methylation maps of human preimplantation development and embryonic stem cell (ESC) derivation, confirming a transient state of global hypomethylation that includes most CpGs, while sites of persistent maintenance are primarily restricted to gene bodies. While most features share similar dynamics to mouse, maternally contributed methylation is divergently targeted to species-specific sets of CpG island (CGI) promoters that extend beyond known Imprint Control Regions (ICRs). Retrotransposon regulation is also highly diverse and transitions from maternally to embryonically expressed, species-specific elements. Together, our data confirm that paternal genome demethylation is a general attribute of early mammalian development that is characterized by distinct modes of epigenetic regulation