A high degree of developmental plasticity enables plants to adapt to continuous, often unfavorable and unpredictable changes in their environment. At the molecular level, adaptive advantages for plants are primarily provided by epigenetic machinery including DNA methylation, histone modifications, and the activity of noncoding RNA molecules. Using a mass spectrometry-based proteomic approach, we examined the levels of acetylated histone peptide forms in Arabidopsis plants with a loss of function of histone deacetylase 6 (HDA6), and in plants germinated in the presence of HDA inhibitors trichostatin A (TSA) and sodium butyrate (NaB). Our analyses revealed particular lysine sites at histone sequences targeted by the HDA6 enzyme, and by TSA- and NaB-sensitive HDAs. Compared with plants exposed to drugs, more dramatic changes in the overall profiles of histone post-translational modifications were identified in hda6 mutants. However, loss of HDA6 was not sufficient by itself to induce hyperacetylation to the maximum degree, implying complementary activities of other HDAs. In contrast to hda6 mutants that did not exhibit any obvious phenotypic defects, the phenotypes of seedlings exposed to HDA inhibitors were markedly affected, showing that the effect of these drugs on early plant development is not limited to the modulation of histone acetylation levels.

• MeSH
• Arabidopsis genetika   růst a vývoj   MeSH
• histondeacetylasy genetika   MeSH
• histonový kód účinky léků   genetika   MeSH
• inhibitory histondeacetylas farmakologie   MeSH
• klíčení genetika   MeSH
• kyselina máselná farmakologie   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• metylace DNA účinky léků   MeSH
• proteiny huseníčku antagonisté a inhibitory   genetika   MeSH
• proteomika * MeSH
• regulace genové exprese u rostlin MeSH
• semenáček účinky léků   genetika   MeSH
• umlčování genů MeSH
• vývoj rostlin účinky léků   genetika   MeSH
• Publikační typ
• časopisecké články MeSH

MAIN CONCLUSION: Contrasting patterns of histone modifications between the X and Y chromosome in Silene latifolia show euchromatic histone mark depletion on the Y chromosome and indicate hyperactivation of one X chromosome in females. Silene latifolia (white campion) is a dioecious plant with heteromorphic sex chromosomes (24, XX in females and 24, XY in males), and a genetically degenerated Y chromosome that is 1.4 times larger than the X chromosome. Although the two sex chromosomes differ in their DNA content, information about epigenetic histone marks and evidence of their function are scarce. We performed immunolabeling experiments using antibodies specific for active and suppressive histone modifications as well as pericentromere-specific histone modifications. We show that the Y chromosome is partially depleted of histone modifications important for transcriptionally active chromatin, and carries these marks only in the pseudo-autosomal region, but that it is not enriched for suppressive and pericentromere histone marks. We also show that two of the active marks are specifically enriched in one of the X chromosomes in females and in the X chromosome in males. Our data support recent findings that genetic imprinting mediates dosage compensation of sex chromosomes in S. latifolia.

• MeSH
• chromozomy rostlin genetika   MeSH
• epigeneze genetická * MeSH
• histonový kód genetika   MeSH
• Silene genetika   MeSH
• Publikační typ
• časopisecké články MeSH

Epigenetic mechanisms have not been characterized in ticks despite their importance as vectors of human and animal diseases worldwide. The objective of this study was to characterize the histones and histone modifying enzymes (HMEs) of the tick vector Ixodes scapularis and their role during Anaplasma phagocytophilum infection. We first identified 5 histones and 34 HMEs in I. scapularis in comparison with similar proteins in model organisms. Then, we used transcriptomic and proteomic data to analyze the mRNA and protein levels of I. scapularis histones and HMEs in response to A. phagocytophilum infection of tick tissues and cultured cells. Finally, selected HMEs were functionally characterized by pharmacological studies in cultured tick cells. The results suggest that A. phagocytophilum manipulates tick cell epigenetics to increase I. scapularis p300/CBP, histone deacetylase, and Sirtuin levels, resulting in an inhibition of cell apoptosis that in turn facilitates pathogen infection and multiplication. These results also suggest that a compensatory mechanism might exist by which A. phagocytophilum manipulates tick HMEs to regulate transcription and apoptosis in a tissue-specific manner to facilitate infection, but preserving tick fitness to guarantee survival of both pathogens and ticks. Our study also indicates that the pathogen manipulates arthropod and vertebrate cell epigenetics in similar ways to inhibit the host response to infection. Epigenetic regulation of tick biological processes is an essential element of the infection by A. phagocytophilum and the study of the mechanisms and principal actors involved is likely to provide clues for the development of anti-tick drugs and vaccines.

• MeSH
• Anaplasma phagocytophilum genetika   MeSH
• apoptóza genetika   MeSH
• buněčné linie MeSH
• epigeneze genetická * MeSH
• histonový kód genetika   MeSH
• histony genetika   metabolismus   MeSH
• hmyz - vektory genetika   MeSH
• interakce hostitele a patogenu genetika   MeSH
• klíště genetika   MeSH
• lidé MeSH
• messenger RNA biosyntéza   genetika   MeSH
• transkripční faktory p300-CBP biosyntéza   genetika   MeSH
• transkriptom genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH