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1

Chromatin structure and transcriptional activity of MAG gene

100%
Konat G. W.
Acta Neurobiologiae Experimentalis
|
1996
|
tom 56
|
nr 1
2

Structural damage to nuclear DNA in mammalian spermatozoa: its evaluation techniques and relationship with male infertility

75%
Fraser L.
Polish Journal of Veterinary Sciences
|
2004
|
tom 07
|
nr 4
Diagnosis of the fertilizing ability of a semen sample is important for consistently high reproductive efficiency. Disturbances in the organization of the genomic material in sperm nuclei can have a serious impact on the growth of the offspring, therefore a stable nuclear matrix is crucial for participation in embryonic development. Routine semen analysis investigates parameters such as sperm motility and morphology, but does not examine the nuclear DNA integrity of spermatozoa. It has been suggested that altered nuclear chromatin structure or damaged DNA in spermatozoa is implicated as a possible cause of increased infertility in males. Therefore, it is crucial to develop and use accurate and diagnostic tests, which may provide better prognostic capabilities than the standard sperm assessments. This article reviews and discusses some of the current techniques employed for evaluating chromatin structure or DNA damage in spermatozoa. These different techniques include the comet assay, sperm chromatin structure assay (SCSA), acridine orange test (AOT), tritium-labelled 3H-actinomycin D (3H-AMD) incorporation assay, terminal TdT-mediated dUTP-nick-end labelling (TUNEL) assay, in-situ nick translation (ISNT) assay, DNA breakage detection-fluorescence in-situ hybridizations (DBD-FISH) assay and sperm chromatin dispersion (SCD) test. The aforementioned assays, which are considered independent measure of sperm quality, may help to detect subtle defects in the chromatin structure or DNA integrity, and thereby assist in semen quality assessment. The relationship between DNA damage and male infertility is also addressed.
3

Further ultrastructural research of Chara vulgaris spermiogenesis: endoplasmic reticulum, structure of chromatin, 3H-lysine and 3H-arginine incorporation

75%
Kwiatkowska M., Poplonska K.
Folia Histochemica et Cytobiologica
|
2002
|
tom 40
|
nr 2
4

H3K4 histone methylation in oral squamous cell carcinoma

63%
Mancuso M., Matassa D. S., Conte M., Colella G., Rana G., Fucci L., Piscopo M.
Acta Biochimica Polonica
|
2009
|
tom 56
|
nr 3
405-410
Methylation of specific lysine residues in histone tails has been proposed to function as a stable epigenetic marker that directs biological functions altering chromatin structure. Recent findings have implicated alteration in heterochromatin formation as a contributing factor in cancer development. In order to verify whether changes in the overall level of H3K4 histone methylation could be involved in oral squamous carcinoma, the levels of H3K4me1, me2 and me3 were measured in oral squamous carcinoma, leukoplakias and normal tissues. The levels of H3K4me2 and me3 were significantly different in oral squamous cell carcinoma in comparison with normal tissue: the level of H3K4me2 was increased while that of H3K4me3 decreased. No significant differences could be found between the two types of tissues in the level of H3K4me1. A similar trend was found in the leukoplakias that appeared more like the pathological than normal tissue. These results support the idea that alteration of chromatin structure could contribute to oncogenic potential
5

Histone modifications under environmental stress

63%
Pawlak S., Deckert J.
Biological Letters
|
2007
|
tom 44
|
nr 2
65-73
6

The nuclear lamins and the nuclear envelope

63%
Rzepecki R.
Cellular and Molecular Biology Letters
|
2002
|
tom 07
|
nr 4
The cell nucleus is separated from the rest of the cell by the nuclear envelope. The nuclear envelope, nuclear envelope proteins and nuclear lamina organise the structure of the entire nucleus and the chromatin via a myriad of interactions. These interactions are dynamic, change with the change (progress) of the cell cycle, with cell differentiation and with changes in cell physiology.
7

Application of IGF2 - specific identifier probe for cytogenetic study of somatic and sperm cells in horses

63%
Potocki L., Bugno-Poniewierska M., Tischner M., Wnuk M.
Folia Biologica
|
2011
|
tom 59
|
nr 3-4
8

Epigenetic modulation of neural stem cells: The influence on reprogramming and differentiation

63%
Buzanska L., Szablowska-Gadomska I.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr 1
The differences between pluripotent and differentiated cells include stage specific chromatin structure and transcriptional hierarchy which are both regulated by and orchestrated with the epigenetic events. Such events include alterations in DNA methylation, histone modifications, polycomb gene group and noncoding RNA expression. In this lecture the overview will be given on chromatin dynamics and epigenetic modification status during neural stem cell development. Examples of regulatory machineries responsible for gene repression at each stage of neural stem cell development will be indicated. Neural stem cells are characterized by their ability to give rise to multiple neural lineages, including neurons, astrocytes, and oligodendrocytes. Previously we have obtained neural stem cells from human cord blood (HUCB-NSC) which has been investigated by our group for their ability to be reprogrammed or differentiated using combination of small molecules as epigenetic modulators. It was demonstrated that the influence of small chemicals: histone deacetylases (Trichostatin A -TSA) and methyltransferases (RG-108) on the expression of Oct4, Sox2, Rex1 and Nanog genes depended on developmental stages of HUCB-NSC. Incubation for 5 days in reprogramming conditions followed by short time culture (3 days) in ESCM (Embryonic Stem Cell Medium) on Matrigel resulted with only partial stimulation of the investigated pluripotency markers. Nevertheless, the differences in expression pattern between tested treatment conditions were observed. Cells grown under Serum Free culture conditions treated with a combination of epigenetic inhibitors as well as recombinant proteins after longer incubation in ESCM on Matrigel were able to gain full iPS morphology and showed continuous expression of pluripotent genes. None of the mentioned above factors were alone sufficient to reprogram NSC to stable pluripotency state. Additionally the mechanism of regulation DNMTs and HDACs genes (namely DNMT 3B and HDAC1) by methyltransferases and histone deacetylases inhibitors and their role in reprogramming and differentiation process of HUCB-NSC have been tested. The present study demonstated that small molecules such as TSA and RG108 together with reprogramming proteins in lowered oxygen conditions can change epigenetic status of cells and activate and sustain pluripotent state in HUCB-NSC. In conclusion it is evident that the developmental stage of the cells and epigenetic modulation play an important role in the induction of pluripotency genes expression. Sponsored by grant from Polish Ministry of Scientific Research and Higher Education Nr 5978/B/PO1/2010/38
9

Nucleosomes and regulation of gene expression. Structure of the HIV-1 5'LTR

63%
Widlak P., Garrard W. T.
Acta Biochimica Polonica
|
1998
|
tom 45
|
nr 1
Packaging of DNA into chromatin adds complexity to the problem of regulation of gene expression. Nucleosomes affect the accessibility of transcription factors to occupy their binding sites in chromatin of eukaryotic cells. The disruption of nucleosome structure within the enhancer/promoter region of the integrated HIV-1 proviral genome is an instructive example of a chromatin remodeling process during transcriptional activation. To investigate the mechanism responsible for generating nuclease hypersensitive sites that exist in vivo in the promoter/enhancer region of the 5'LTR (long terminal repeat) of integrated HIV-1 we have utilized an in vitro chromatin assembly system with Xenopus oocyte extracts. Chromatin assembly in the presence of Sp1 and NFκB transcription factors induces DNase I hypersensitive sites on either side of their binding sites and positions the adjacent nucleosomes. This structure can also be formed in a factor-induced, ATP-dependent chromatin remodeling process and closely resembles the in vivo chromatin structure. The DNase I hypersensitive sites that form within the HIV LTR are probably histone-free and remain after removal of transcription factors.
10

Examination of sperm chromatin structure and fertility of boar semen

63%
Bochenek M., Smorag Z., Rozycki M., Dziadek K.
Roczniki Naukowe Zootechniki
|
2000
|
tom 27
|
nr 2
11

DNA microarrays, a novel approach in studies of chromatin structure

63%
Widlak P.
Acta Biochimica Polonica
|
2004
|
tom 51
|
nr 1
The DNA microarray technology delivers an experimental tool that allows survey­ing expression of genetic information on a genome-wide scale at the level of single genes — for the new field termed functional genomics. Gene expression profiling — the primary application of DNA microarrays technology — generates monumental amounts of information concerning the functioning of genes, cells and organisms. However, the expression of genetic information is regulated by a number of factors that cannot be directly targeted by standard gene expression profiling. The genetic material of eukaryotic cells is packed into chromatin which provides the compaction and organization of DNA for replication, repair and recombination processes, and is the major epigenetic factor determining the expression of genetic information. Genomic DNA can be methylated and this modification modulates interactions with proteins which change the functional status of genes. Both chromatin structure and transcriptional activity are affected by the processes of replication, recombination and repair. Modified DNA microarray technology could be applied to genome-wide study of epigenetic factors and processes that modulate the expression of genetic in­formation. Attempts to use DNA microarrays in studies of chromatin packing state, chromatin/DNA-binding protein distribution and DNA methylation pattern on a ge­nome-wide scale are briefly reviewed in this paper.
12
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Changes in distribution of 5' methylcytosine in male and female gametophyte of Hyacinthus orientalis before and after fertilization

51%
Kozlowska M., Niedojadlo K., Bednarska-Kozakiewicz E.
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
|
2013
|
tom 94
|
nr 3
13

Evaluation of protamines 1 and 2 transcript contents in spermatozoa from asthenozoospermic men

51%
Kempisty B., Depa-Martynow M., Lianeri M., Jedrzejczak P., Darul-Wasowicz A., Jagodzinski P. P.
Folia Histochemica et Cytobiologica. Supplement
|
2007
|
tom 45
|
nr 1
109-113
14

Polyploidization of stigmatic papillae in Triglochin maritimum L. [Juncaginaceae]

51%
Bohdanowicz J., Dabrowska D.
Acta Biologica Cracoviensia. Series Botanica
|
1997
|
tom 39
The cytological differentiation of the dry papillate stigma in Triglochin maritimum L. (Juncaginaceae) was studied. The polyploidization process started soon after the formation of unicellular stigmatic papillae. Later, huge, long papillae with single enlarged nuclei constituted the receptive surface of the maturing stigma. The nuclear DNA content of the polyploid papillae and of telophasic (2C) and prophasic (4C) cells of the ovule was measured cytophotometrically after Feulgen staining. Analysis of nuclear DNA content measurements permitted the degrees of ploidy reached by the papillae to be established. Nuclei with DNA content corresponding to levels of 4C, 8C, 16C, 32C and 64C were found in the mature stigma. The most common were nuclei with DNA content of 16C (29%) and 32C (24%). The absence of mitoses, rhythmical enlargement of the DNA content of the nuclei as well as their characteristic endochromocenters, pointed to endoreduplication as the mechanism of polyploidization of the stigmatic papillae.
15

DNA changes induced by gamma-irradiation in onion

51%
Habdas H., Staniaszek M.
Prace Naukowe Uniwersytetu Śląskiego w Katowicach
|
1998
|
tom 1696
16

Effects of antheridial peptides derived from Chara on cell cycle-regulated processes in human and yeast cells

51%
Maszewski J., Maszewska M., Polit J.
Folia Histochemica et Cytobiologica
|
1999
|
tom 37
|
nr 3
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