Immunofluorescent staining reveals hypermethylation of microchromosomes in the central bearded dragon, Pogona vitticeps

Molecular Cytogenetics

Janine E. Deakin³  Tariq Ezaz³  Sudha Rao¹  Alexandra M. Livernois³  Renae Domaschenz² 

[1] Discipline of Biomedical Sciences, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra 2601, ACT, Australia;Present address: John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia;Institute for Applied Ecology, University of Canberra, Canberra 2601, ACT, Australia

关键词: Epigenetics;    Histone modifications;    Methylation;    Reptiles;   

Others  :  1235197
DOI  :  10.1186/s13039-015-0208-6

 received in 2015-10-26, accepted in 2015-12-18,  发布年份 2015

【 摘 要 】

Background

Studies of model organisms have demonstrated that DNA cytosine methylation and histone modifications are key regulators of gene expression in biological processes. Comparatively little is known about the presence and distribution of epigenetic marks in non-model amniotes such as non-avian reptiles whose genomes are typically packaged into chromosomes of distinct size classes. Studies of chicken karyotypes have associated the gene-richness and high GC content of microchromosomes with a distinct epigenetic landscape. To determine whether this is likely to be a common feature of amniote microchromosomes, we have analysed the distribution of epigenetic marks using immunofluorescence on metaphase chromosomes of the central bearded dragon (Pogona vitticeps). This study is the first to study the distribution of epigenetic marks on non-avian reptile chromosomes.

Results

We observed an enrichment of DNA cytosine methylation, active modifications H3K4me2 and H3K4me3, as well as the repressive mark H3K27me3 in telomeric regions on macro and microchromosomes. Microchromosomes were hypermethylated compared to macrochromosomes, as they are in chicken. However, differences between macro- and microchromosomes for histone modifications associated with actively transcribed or repressed DNA were either less distinct or not detectable.

Conclusions

Hypermethylation of microchromosomes compared to macrochromosomes is a shared feature between P. vitticeps and avian species. The lack of the clear distinction between macro- and microchromosome staining patterns for active and repressive histone modifications makes it difficult to determine at this stage whether microchrosome hypermethylation is correlated with greater gene density as it is in aves, or associated with the greater GC content of P. vitticeps microchromosomes compared to macrochromosomes.

【 授权许可】

   
2015 Domaschenz et al.

【 图 表 】

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