Euchromatic domains in plant chromosomes as revealed by H4 histone acetylation and early DNA replication

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 343-350 ◽  
Author(s):  
Boris Vyskot ◽  
Jiri Siroky ◽  
Renata Hladilova ◽  
Nikolai D Belyaev ◽  
Bryan M Turner
Keyword(s):  
Dna Replication ◽  
Sex Chromosomes ◽  
Silene Latifolia ◽  
Histone H4 ◽  
X Chromosomes ◽  
Plant Chromosomes ◽  
Histone H4 Acetylation ◽  
Immunofluorescence Labeling ◽  
Silene Species ◽  
Chromosome Regions

Using specific polyclonal antisera raised against acetylated isoforms of histone H4, we have analyzed their distribution in the dioecious plant Silene latifolia (syn.Melandrium album) possessing heteromorphic sex chromosomes. Our previous studies on this species have shown that one of the two X chromosomes in homogametic female cells is heavily methylated and late replicating, as a possible consequence of dosage compensation. Here we report that there are no detectable differences in intensity and distribution of H4 acetylation between these two X chromosomes. In S. latifolia only distal-subtelomeric chromosome regions, on both the sex chromosomes and autosomes, display strong signals of H4 acetylation at N-terminal lysines 5, 8, and 12. These acetylated domains correspond to the very early replicating distal chromosome regions as revealed by 5-bromodeoxyuridine pulses followed by the indirect immunofluorescence microscopy. The distribution of H4 acetylated at lysine 16 was uniform along the chromosomes. The unique distal-subtelomeric H4 acetylation signals were also observed in three other Silene species (S. vulgaris, S. pendula, andS. chalcedonica), but not in two non-related plant species tested (Allium cepa and Nicotiana tabacum). The presented data as well as our recent studies on the structure of S. latifolia chromosome ends indicate that Silene species possess the specific distal-subtelomeric location of euchromatin, gene-rich regions on chromosomes.Key words: histone H4 acetylation, DNA replication, euchromatin, immunofluorescence labeling, Silene spp.

scholarly journals Localization of Male-Specifically Expressed MROS Genes of Silene latifolia by PCR on Flow-Sorted Sex Chromosomes and Autosomes

Genetics ◽  
2001 ◽  
Vol 158 (3) ◽  
pp. 1269-1277
Author(s):  
Eduard Kejnovský ◽  
Jan Vrána ◽  
Sachihiro Matsunaga ◽  
Přemysl Souček ◽  
Jiří Široký ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Silene Latifolia ◽  
Homology Search ◽  
X Chromosomes ◽  
Dioecious Plants ◽  
Flow Sorting ◽  
Heteromorphic Sex Chromosomes ◽  
Copy Gene ◽  
Melandrium Album ◽  
Pcr Products

Abstract The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S. latifolia. To localize the MROS genes, we used the flow-sorted X chromosomes and autosomes as a template for PCR with internal primers. Our results indicate that the MROS3 gene is located in at least two copies tandemly arranged on the X chromosome with additional copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusively autosomal. The specificity of PCR products was checked by digestion with a restriction enzyme or reamplification using nested primers. Homology search of databases has shown the presence of five MROS3 homologues in A. thaliana, four of them arranged in two tandems, each consisting of two copies. We conclude that MROS3 is a low-copy gene family, connected with the proper pollen development, which is present not only in dioecious but also in other dicot plant species.

DIFFERENTIAL DNA REPLICATION IN THE XX AND XY CELLS OF MUSCA DOMESTICA L. OCRA STRAIN

1970 ◽  
Vol 12 (3) ◽  
pp. 461-473 ◽  
Author(s):  
K. Y. Jan ◽  
J. W. Boyes
Keyword(s):  
Dna Replication ◽  
Musca Domestica ◽  
Sex Chromosomes ◽  
Chromosome Length ◽  
Final Part ◽  
X Chromosomes ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes ◽  
Autosomal Pair ◽  
Differential Dna Replication

The karyotype of Musca domestica L. ocra strain, consists of the sex chromosomes and five autosomal pairs. The heteromorphic sex chromosomes are heterochromatic and mitotically unpaired, whereas the autosomes are euchromatic and mitotically paired. All autosomal pairs and both X and Y chromosomes are cytologically recognizable.The relative labelling rate, R (in terms of the number of grains counted per 100 labelled metaphases per μ of chromosome length) for the sex chromosomes and for each autosomal pair was followed from 1.5 hours to 8 hours after H3TdR injection. The pattern of labelling rate was similar for the different autosomal pairs in the XX cells but this pattern for the autosomal pairs in the XY cells, though also similar for the different pairs, differed appreciably from that found in the XX cells. The pattern of the labelling rate for the X chromosomes was similar in the XX and XY cells. Also the pattern of labelling rate for the X and Y chromosomes was similar during the final part of the replication period. The two X chromosomes in the XX cells and the X and Y chromosomes in the XY cells completed labelling later than the autosomes.

scholarly journals Protein kinase D1 phosphorylation of KAT7 enhances its protein stability and promotes replication licensing and cell proliferation

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Yao Liang ◽  
Yuanyuan Su ◽  
Chenzhong Xu ◽  
Na Zhang ◽  
Doudou Liu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Dna Replication ◽  
Protein Kinase ◽  
Histone H4 ◽  
Replication Complex ◽  
Protein Kinase D1 ◽  
Defective Mutant ◽  
Histone H4 Acetylation

Abstract The histone acetyltransferase (HAT) KAT7/HBO1/MYST2 plays a crucial role in the pre-replication complex (pre-RC) formation, DNA replication and cell proliferation via acetylation of histone H4 and H3. In a search for protein kinase D1 (PKD1)-interacting proteins, we have identified KAT7 as a potential PKD1 substrate. We show that PKD1 directly interacts and phosphorylates KAT7 at Thr97 and Thr331 in vitro and in vivo. PKD1-mediated phosphorylation of KAT7 enhances its expression levels and stability by reducing its ubiquitination-mediated degradation. Significantly, the phospho-defective mutant KAT7-Thr97/331A attenuates histone H4 acetylation levels, MCM2/6 loading on the chromatin, DNA replication and cell proliferation. Similarly, PKD1 knockdown decreases, whereas the constitutive active mutant PKD1-CA increases histone H4 acetylation levels and MCM2/6 loading on the chromatin. Overall, these results suggest that PKD1-mediated phosphorylation of KAT7 may be required for pre-RC formation and DNA replication.

LTR retrotransposons in the dioecious plant Silene latifolia

Genome ◽  
2002 ◽  
Vol 45 (4) ◽  
pp. 745-751 ◽  
Author(s):  
Sachihiro Matsunaga ◽  
Fumi Yagisawa ◽  
Maki Yamamoto ◽  
Wakana Uchida ◽  
Shunsuke Nakao ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
Silene Latifolia ◽  
Ltr Retrotransposons ◽  
Dioecious Plant ◽  
Dioecious Species ◽  
Y Chromosomes ◽  
Genus Silene ◽  
Silene Species

Conserved domains of two types of LTR retrotransposons, Ty1–copia- and Ty3–gypsy-like retrotransposons, were isolated from the dioecious plant Silene latifolia, whose sex is determined by X and Y chromosomes. Southern hybridization analyses using these retrotransposons as probes resulted in identical patterns from male and female genomes. Fluorescence in situ hybridization indicated that these retrotransposons do not accumulate specifically in the sex chromosomes. These results suggest that recombination between the sex chromosomes of S. latifolia has not been severely reduced. Conserved reverse transcriptase regions of Ty1–copia-like retrotransposons were isolated from 13 different Silene species and classified into two major families. Their categorization suggests that parallel divergence of the Ty1–copia-like retrotransposons occurred during the differentiation of Silene species. Most functional retrotransposons from three dioecious species, S. latifolia, S. dioica, and S. diclinis, fell into two clusters. The evolutionary dynamics of retrotransposons implies that, in the genus Silene, dioecious species evolved recently from gynodioecious species.Key words: retrotransposon, dioecious plant, sex chromosome.

scholarly journals NuA4 Subunit Yng2 Function in Intra-S-Phase DNA Damage Response

2002 ◽  
Vol 22 (23) ◽  
pp. 8215-8225 ◽  
Author(s):  
John S. Choy ◽  
Stephen J. Kron
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Histone Acetylation ◽  
Trichostatin A ◽  
S Phase ◽  
Open Chromatin ◽  
Histone H4 ◽  
Histone H4 Acetylation ◽  
Histone Deacetylase Inhibitor Trichostatin ◽  
Nucleosomal Histone

ABSTRACT While regulated transcription requires acetylation of histone N-terminal tails to promote an open chromatin conformation, a similar role for histone acetylation in DNA replication and/or repair remains to be established. Cells lacking the NuA4 subunit Yng2 are viable but critically deficient for genome-wide nucleosomal histone H4 acetylation. We found that yng2 mutants are specifically sensitized to DNA damage in S phase induced by cdc8 or cdc9 mutations, hydroxyurea, camptothecin, or methylmethane sulfonate (MMS). In yng2, MMS treatment causes a persistent Mec1-dependent intra-S-phase checkpoint delay characterized by slow DNA repair. Restoring H4 acetylation with the histone deacetylase inhibitor trichostatin A promotes checkpoint recovery. In turn, mutants lacking the histone H3-specific acetyltransferase GCN5 are similarly sensitive to intra-S-phase DNA damage. The inviability of gcn5 yng2 double mutants suggests overlapping roles for H3 and H4 acetylation in DNA replication and repair. Paradoxically, haploid yng2 mutants do not tolerate mutations in genes important for nonhomologous end joining repair yet remain proficient for homologous recombination. Our results implicate nucleosomal histone acetylation in maintaining genomic integrity during chromosomal replication.

scholarly journals Studies on Metatherian Sex Chromosomes III. The Use of Tritiated Uridine-induced Chromosome Aberrations to Distinguish Active and Inactive X Chromosomes

1977 ◽  
Vol 30 (2) ◽  
pp. 103 ◽  
Author(s):  
Jennifer A Donald ◽  
DW Cooper
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Aberrations ◽  
X Inactivation ◽  
Facultative Heterochromatin ◽  
Hybrid Female ◽  
X Chromosomes ◽  
Toxicity Effect ◽  
Red Kangaroo ◽  
Chromosome Regions

The paternal X inactivation system of kangaroos has been investigated in this study by using tritiated uridine-induced chromosome aberrations to distinguish the active from the inactive X. Previous work in eutherian mammals has demonstrated that constitutive heterochromatic chromosome regions are less susceptible to breakage by tritiated uri dine than euchromatic regions. The results of a comparison between the paternal X chromosome of a wallaroo x red kangaroo hybrid female and the two X chromosomes of a red kangaroo female suggested that the facultative heterochromatin of the X is also less susceptible to breakage by this treatment. However there were significantly more breaks of the paternal X in fibroblasts than in lymphocytes of the hybrid female, which agrees with biochemical findings suggesting activation of the paternal X in fibroblasts. Our results strengthen the suggestion of other workers that the reduced number of aberrations in heterochromatin occurs because such breaks occur principally when the DNA and labelled RNA are in apposition during transcription. Some evidence was found of an apparent toxicity effect of the tritiated uridine solution on the cells.

C-banded karyotypes of two Silene species with heteromorphic sex chromosomes

Genome ◽  
2002 ◽  
Vol 45 (2) ◽  
pp. 243-252 ◽  
Author(s):  
Aleksandra Grabowska-Joachimiak ◽  
Andrzej Joachimiak
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Silene Latifolia ◽  
Silene Dioica ◽  
Dna Amount ◽  
Metaphase Chromosomes ◽  
X Chromosomes ◽  
C Banding ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes

Mitotic metaphase chromosomes of Silene latifolia (white campion) and Silene dioica (red campion) were studied and no substantial differences between the conventional karyotypes of these two species were detected. The classification of chromosomes into three distinct groups proposed for S. latifolia by Ciupercescu and colleagues was considered and discussed. Additionally, a new small satellite on the shorter arm of homobrachial chromosome 5 was found. Giemsa C-banded chromosomes of the two analysed species show many fixed and polymorphic heterochromatic bands, mainly distally and centromerically located. Our C-banding studies provided an opportunity to better characterize the sex chromosomes and some autosome types, and to detect differences between the two Silene karyotypes. It was shown that S. latifolia possesses a larger amount of polymorphic heterochromatin, especially of the centromeric type. The two Silene sex chromosomes are easily distinguishable not only by length or DNA amount differences but also by their Giemsa C-banding patterns. All Y chromosomes invariably show only one distally located band, and no other fixed or polymorphic bands on this chromosome were observed in either species. The X chromosomes possess two terminally located fixed bands, and some S. latifolia X chromosomes also have an extra-centric segment of variable length. The heterochromatin amount and distribution revealed by our Giemsa C-banding studies provide a clue to the problem of sex chromosome and karyotype evolution in these two closely related dioecious Silene species.Key words: dioecious plant, Silene dioica, Silene latifolia, karyotype, sex chromosomes, heterochromatin, C-banding.

scholarly journals Hbo1 Links p53-Dependent Stress Signaling to DNA Replication Licensing

2007 ◽  
Vol 28 (1) ◽  
pp. 140-153 ◽  
Author(s):  
Masayoshi Iizuka ◽  
Olga F. Sarmento ◽  
Takao Sekiya ◽  
Heidi Scrable ◽  
C. David Allis ◽  
...  
Keyword(s):  
Dna Replication ◽  
Molecular Mechanisms ◽  
Protein Complexes ◽  
Stress Signaling ◽  
Dependent Manner ◽  
Histone H4 ◽  
Steroid Dependent ◽  
Histone H4 Acetylation ◽  
Replication Fork Arrest

ABSTRACT Hbo1 is a histone acetyltransferase (HAT) that is required for global histone H4 acetylation, steroid-dependent transcription, and chromatin loading of MCM2-7 during DNA replication licensing. It is the catalytic subunit of protein complexes that include ING and JADE proteins, growth regulatory factors and candidate tumor suppressors. These complexes are thought to act via tumor suppressor p53, but the molecular mechanisms and links between stress signaling and chromatin, are currently unknown. Here, we show that p53 physically interacts with Hbo1 and negatively regulates its HAT activity in vitro and in cells. Two physiological stresses that stabilize p53, hyperosmotic shock and DNA replication fork arrest, also inhibit Hbo1 HAT activity in a p53-dependent manner. Hyperosmotic stress during G1 phase specifically inhibits the loading of the MCM2-7 complex, providing an example of the chromatin output of this pathway. These results reveal a direct regulatory connection between p53-responsive stress signaling and Hbo1-dependent chromatin pathways.

scholarly journals Histone H4 acetylation required for chromatin decompaction during DNA replication

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Kun Ruan ◽  
Takaharu G. Yamamoto ◽  
Haruhiko Asakawa ◽  
Yuji Chikashige ◽  
Hiroshi Kimura ◽  
...  
Keyword(s):  
Dna Replication ◽  
Histone H4 ◽  
Histone H4 Acetylation
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