Presentation Title

Is Epigenetics Involved in the Regulation of Biomineralization in Emiliania huxleyi

Faculty Mentor

Betsy Read

Start Date

23-11-2019 1:30 PM

End Date

23-11-2019 1:45 PM

Location

Markstein 205

Session

oral 3

Type of Presentation

Oral Talk

Subject Area

biological_agricultural_sciences

Abstract

Emiliania huxleyi (E. huxleyi) is one of the most abundant marine phytoplankton in today’s oceans. The tiny coccolithophore produces intricate calcium carbonate disks known as coccoliths that surround the cell. In 1983 samples of E. huxleyi collected off of the coast of Peru were isolated and sent to two culture collections: 1) the National Center for Marine Algae and Microbiota in Bigelow Maine, and 2) the Plymouth Algal Culture Collection in England. After 20 years in culture, CCMP 1516 has lost, and PLY 217 retained its ability to calcify. As isogenic lines it is hypothesized that epigenetic changes may be responsible for these phenotypic differences. Epigenetics refers to heritable changes in gene expression that do not involve alterations in the DNA sequence. These changes include methylation, phosphorylation, and or ubiquitination of DNA bases and/or histone proteins that influence genome packaging and ultimately gene expression. To determine whether methylation may be an epigenetic driver of calcification in E. huxleyi, bisulfite sequencing and RNA-Seq were employed to compare DNA methylation and gene expression levels in CCMP 1516 and PLY 217. Comparisons revealed 12,800 differentially methylated regions and 14,525 differentially expressed genes. Of these, 2,037 genes were differentially expressed and differentially methylated near the transcriptional start site. To independently validate expression, 9 genes previously identified as potentially involved in biomineralization were subjected to Real Time RT-PCR. Differential expression of 5 of the 9 genes tested was confirmed, including that of a Plasma membrane type H pump/ATPase, nucleoside transporter, acyl-coA-binding protein, bacterial Na+/H+ exchanger, and an unknown protein. Differential expression levels varied from 2-10 . Results from this work will be presented together with preliminary data aimed at profiling histone modifications as an epigenetic mechanism that may be involved in the regulation of calcification and cocolithogenisis.

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Nov 23rd, 1:30 PM Nov 23rd, 1:45 PM

Is Epigenetics Involved in the Regulation of Biomineralization in Emiliania huxleyi

Markstein 205

Emiliania huxleyi (E. huxleyi) is one of the most abundant marine phytoplankton in today’s oceans. The tiny coccolithophore produces intricate calcium carbonate disks known as coccoliths that surround the cell. In 1983 samples of E. huxleyi collected off of the coast of Peru were isolated and sent to two culture collections: 1) the National Center for Marine Algae and Microbiota in Bigelow Maine, and 2) the Plymouth Algal Culture Collection in England. After 20 years in culture, CCMP 1516 has lost, and PLY 217 retained its ability to calcify. As isogenic lines it is hypothesized that epigenetic changes may be responsible for these phenotypic differences. Epigenetics refers to heritable changes in gene expression that do not involve alterations in the DNA sequence. These changes include methylation, phosphorylation, and or ubiquitination of DNA bases and/or histone proteins that influence genome packaging and ultimately gene expression. To determine whether methylation may be an epigenetic driver of calcification in E. huxleyi, bisulfite sequencing and RNA-Seq were employed to compare DNA methylation and gene expression levels in CCMP 1516 and PLY 217. Comparisons revealed 12,800 differentially methylated regions and 14,525 differentially expressed genes. Of these, 2,037 genes were differentially expressed and differentially methylated near the transcriptional start site. To independently validate expression, 9 genes previously identified as potentially involved in biomineralization were subjected to Real Time RT-PCR. Differential expression of 5 of the 9 genes tested was confirmed, including that of a Plasma membrane type H pump/ATPase, nucleoside transporter, acyl-coA-binding protein, bacterial Na+/H+ exchanger, and an unknown protein. Differential expression levels varied from 2-10 . Results from this work will be presented together with preliminary data aimed at profiling histone modifications as an epigenetic mechanism that may be involved in the regulation of calcification and cocolithogenisis.