Weizman Eviatar N.

No Thumbnail Available
Last Name
Weizman
First Name
Eviatar N.
ORCID
0000-0001-6549-891X

Filters

2019 - 2019 1 2020 - 2021 1
2
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Article
    Chromatin dynamics enable transcriptional rhythms in the cnidarian Nematostella vectensis
    (Public Library of Science, 2019-11-06) Weizman, Eviatar N. ; Tannenbaum, Miriam ; Tarrant, Ann M. ; Hakim, Ofir ; Levy, Oren
    In animals, circadian rhythms are driven by oscillations in transcription, translation, and proteasomal degradation of highly conserved genes, resulting in diel cycles in the expression of numerous clock-regulated genes. Transcription is largely regulated through the binding of transcription factors to cis-regulatory elements within accessible regions of the chromatin. Chromatin remodeling is linked to circadian regulation in mammals, but it is unknown whether cycles in chromatin accessibility are a general feature of clock-regulated genes throughout evolution. To assess this, we applied an ATAC-seq approach using Nematostella vectensis, grown under two separate light regimes (light:dark (LD) and constant darkness (DD)). Based on previously identified N. vectensis circadian genes, our results show the coupling of chromatin accessibility and circadian transcription rhythmicity under LD conditions. Out of 180 known circadian genes, we were able to list 139 gene promoters that were highly accessible compared to common promoters. Furthermore, under LD conditions, we identified 259 active enhancers as opposed to 333 active enhancers under DD conditions, with 171 enhancers shared between the two treatments. The development of a highly reproducible ATAC-seq protocol integrated with published RNA-seq and ChIP-seq databases revealed the enrichment of transcription factor binding sites (such as C/EBP, homeobox, and MYB), which have not been previously associated with circadian signaling in cnidarians. These results provide new insight into the regulation of cnidarian circadian machinery. Broadly speaking, this supports the notion that the association between chromatin remodeling and circadian regulation arose early in animal evolution as reflected in this non-bilaterian lineage.
  • Article
    Chromatin dynamics and gene expression response to heat exposure in field-conditioned versus laboratory-cultured Nematostella vectensis
    (MDPI, 2021-07-12) Weizman, Eviatar N. ; Rinsky, Mieka ; Simon-Blecher, Noa ; Lampert-Karako, Sarit ; Yaron, Orly ; Tarrant, Ann M. ; Levy, Oren
    Organisms’ survival is associated with the ability to respond to natural or anthropogenic environmental stressors. Frequently, these responses involve changes in gene regulation and expression, consequently altering physiology, development, or behavior. Here, we present modifications in response to heat exposure that mimics extreme summertime field conditions of lab-cultured and field-conditioned Nematostella vectensis. Using ATAC-seq and RNA-seq data, we found that field-conditioned animals had a more concentrated reaction to short-term thermal stress, expressed as enrichment of the DNA repair mechanism pathway. By contrast, lab animals had a more diffuse reaction that involved a larger number of differentially expressed genes and enriched pathways, including amino acid metabolism. Our results demonstrate that pre-conditioning affects the ability to respond efficiently to heat exposure in terms of both chromatin accessibility and gene expression and reinforces the importance of experimentally addressing ecological questions in the field.