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Gene expression in the mixotrophic prymnesiophyte, Prymnesium parvum, responds to prey availability.

Liu Z, Jones AC, Campbell V, Hambright KD, Heidelberg KB, Caron DA - Front Microbiol (2015)

Bottom Line: It produces toxins and can form ecosystem disruptive blooms that result in fish kills and changes in planktonic food web structure.However, both transcriptomic data and growth experiments indicated that P. parvum did not grow faster in the presence of prey despite the gains in nutrients, although algal abundances attained in culture were slightly greater in the presence of prey.The relationship between phototrophy, heterotrophy and growth of P. parvum is discussed.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Southern California Los Angeles, CA, USA.

ABSTRACT
The mixotrophic prymnesiophyte, Prymnesium parvum, is a widely distributed alga with significant ecological importance. It produces toxins and can form ecosystem disruptive blooms that result in fish kills and changes in planktonic food web structure. However, the relationship between P. parvum and its prey on the molecular level is poorly understood. In this study, we used RNA-Seq technology to study changes in gene transcription of P. parvum in three treatments with different microbial populations available as potential prey: axenic P. parvum (no prey), bacterized P. paruvm, and axenic P. parvum with ciliates added as prey. Thousands of genes were differentially expressed among the three treatments. Most notably, transcriptome data indicated that P. parvum obtained organic carbon, including fatty acids, from both bacteria and ciliate prey for energy and cellular building blocks. The data also suggested that different prey provided P. parvum with macro- and micro-nutrients, namely organic nitrogen in the form of amino acids from ciliates, and iron from bacteria. However, both transcriptomic data and growth experiments indicated that P. parvum did not grow faster in the presence of prey despite the gains in nutrients, although algal abundances attained in culture were slightly greater in the presence of prey. The relationship between phototrophy, heterotrophy and growth of P. parvum is discussed.

No MeSH data available.


Average expression levels among different groups of genes of P. parvum in bacterized and ciliate treatment relative to those in axenic treatment. Geometric means ± 95% confidence intervals are shown for relative expression levels against the axenic treatment of genes of each pathway or function. For list of genes and their read counts, FPKM values, and relative expression levels, please refer to Table S2.
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Figure 4: Average expression levels among different groups of genes of P. parvum in bacterized and ciliate treatment relative to those in axenic treatment. Geometric means ± 95% confidence intervals are shown for relative expression levels against the axenic treatment of genes of each pathway or function. For list of genes and their read counts, FPKM values, and relative expression levels, please refer to Table S2.

Mentions: Genes involved in several carbon metabolism pathways had higher expression levels in both treatments with prey, compared to the axenic treatment. Several copies of genes of every step in the fatty acid oxidation pathway, including acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and acetyl-CoA C-acetyltransferase, had ~9-fold higher expression levels when prey, either bacteria or ciliates, were present (Figures 3, 4A). Two genes encoding an electron transfer flavoprotein gene and an electron transfer flavoprotein ubiquinone oxidoreductase that also play a role in fatty acid oxidation (Watmough and Frerman, 2010) had similar transcription patterns (Table S2).


Gene expression in the mixotrophic prymnesiophyte, Prymnesium parvum, responds to prey availability.

Liu Z, Jones AC, Campbell V, Hambright KD, Heidelberg KB, Caron DA - Front Microbiol (2015)

Average expression levels among different groups of genes of P. parvum in bacterized and ciliate treatment relative to those in axenic treatment. Geometric means ± 95% confidence intervals are shown for relative expression levels against the axenic treatment of genes of each pathway or function. For list of genes and their read counts, FPKM values, and relative expression levels, please refer to Table S2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403553&req=5

Figure 4: Average expression levels among different groups of genes of P. parvum in bacterized and ciliate treatment relative to those in axenic treatment. Geometric means ± 95% confidence intervals are shown for relative expression levels against the axenic treatment of genes of each pathway or function. For list of genes and their read counts, FPKM values, and relative expression levels, please refer to Table S2.
Mentions: Genes involved in several carbon metabolism pathways had higher expression levels in both treatments with prey, compared to the axenic treatment. Several copies of genes of every step in the fatty acid oxidation pathway, including acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and acetyl-CoA C-acetyltransferase, had ~9-fold higher expression levels when prey, either bacteria or ciliates, were present (Figures 3, 4A). Two genes encoding an electron transfer flavoprotein gene and an electron transfer flavoprotein ubiquinone oxidoreductase that also play a role in fatty acid oxidation (Watmough and Frerman, 2010) had similar transcription patterns (Table S2).

Bottom Line: It produces toxins and can form ecosystem disruptive blooms that result in fish kills and changes in planktonic food web structure.However, both transcriptomic data and growth experiments indicated that P. parvum did not grow faster in the presence of prey despite the gains in nutrients, although algal abundances attained in culture were slightly greater in the presence of prey.The relationship between phototrophy, heterotrophy and growth of P. parvum is discussed.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Southern California Los Angeles, CA, USA.

ABSTRACT
The mixotrophic prymnesiophyte, Prymnesium parvum, is a widely distributed alga with significant ecological importance. It produces toxins and can form ecosystem disruptive blooms that result in fish kills and changes in planktonic food web structure. However, the relationship between P. parvum and its prey on the molecular level is poorly understood. In this study, we used RNA-Seq technology to study changes in gene transcription of P. parvum in three treatments with different microbial populations available as potential prey: axenic P. parvum (no prey), bacterized P. paruvm, and axenic P. parvum with ciliates added as prey. Thousands of genes were differentially expressed among the three treatments. Most notably, transcriptome data indicated that P. parvum obtained organic carbon, including fatty acids, from both bacteria and ciliate prey for energy and cellular building blocks. The data also suggested that different prey provided P. parvum with macro- and micro-nutrients, namely organic nitrogen in the form of amino acids from ciliates, and iron from bacteria. However, both transcriptomic data and growth experiments indicated that P. parvum did not grow faster in the presence of prey despite the gains in nutrients, although algal abundances attained in culture were slightly greater in the presence of prey. The relationship between phototrophy, heterotrophy and growth of P. parvum is discussed.

No MeSH data available.