Differential transcriptomic responses of ancient and modern Daphnia genotypes to phosphorus supply

作者：Roy Chowdhury Priyanka^*; Frisch Dagmar; Becker Doerthe; Lopez Jacqueline A; Weider Lawrence J; Colbourne John K; Jeyasingh Punidan D

来源：Molecular Ecology, 2015, 24(1): 123-135.

DOI：10.1111/mec.13009

• dietary imbalance
• ecological stoichiometry
• environmental change
• microarray
• nutritional physiology
• phosphorus limitation
• resurrection ecology
• transcriptomics

Little is known about the role of transcriptomic changes in driving phenotypic evolution in natural populations, particularly in response to anthropogenic environmental change. Previous analyses of Daphnia genotypes separated by centuries of evolution in a lake using methods in resurrection ecology revealed striking genetic and phenotypic shifts that were highly correlated with anthropogenic environmental change, specifically phosphorus (P)-driven nutrient enrichment (i.e. eutrophication). Here, we compared the transcriptomes of two ancient (similar to 700-year-old) and two modern (similar to 10-year-old) genotypes in historic (low P) and contemporary (high P) environmental conditions using microarrays. We found considerable transcriptomic variation between ancient' and modern' genotypes in both treatments, with stressful (low P) conditions eliciting differential expression (DE) of a larger number of genes. Further, more genes were DE between ancient' and modern' genotypes than within these groups. Expression patterns of individual genes differed greatly among genotypes, suggesting that different transcriptomic responses can result in similar phenotypes. While this confounded patterns between ancient' and modern' genotypes at the gene level, patterns were discernible at the functional level: annotation of DE genes revealed particular enrichment of genes involved in metabolic pathways in response to P-treatments. Analyses of gene families suggested significant DE in pathways already known to be important in dealing with P-limitation in Daphnia as well as in other organisms. Such observations on genotypes of a single natural population, separated by hundreds of years of evolution in contrasting environmental conditions before and during anthropogenic environmental changes, highlight the important role of transcriptional mechanisms in the evolutionary responses of populations.

• 出版日期2015-1