MicroRNAs (miRNAs) are small, non-coding and regulatory RNAs about 20 to 24 nucleotides long. Their conserved nature among the various organisms makes them a good source of new miRNAs discovery by comparative genomics...MicroRNAs (miRNAs) are small, non-coding and regulatory RNAs about 20 to 24 nucleotides long. Their conserved nature among the various organisms makes them a good source of new miRNAs discovery by comparative genomics approach. This study resulted in 34 miRNAs belonging to 21 families in ecological model plant Mimulus. All the miRNA families (mir 156, 157, 159, 160, 164, 172, 319, 393, 395, 397, 399, 400, 403, 417, 419, 472, 782, 854, 858, 867 and 2112) are found for the first time in Mimulus. The MIR-399 is found as precursor miRNA cluster with 4 mature sequences. All 34 miRNA precursors form stable minimum free energy stem loop structure as their orthologues form and the mature miRNAs reside in the stem portion of the stem loop structure. Twenty eight are from Mimulus guttatus and six miRNAs belong to Mimulus lewisii. Their targets consist of dihy-droflavonol-4-reductase, cycloidea-like protein, DNA-directed RNA polymerase II, maturase (matR) and transcription factors like;squamosa-promoter binding, MYB, palmate-like pentafoliata 1.展开更多
Hybridization is a creative evolutionary force,increasing genomic diversity and facilitating adaptation and even speciation.Hybrids often face significant challenges to establishment,including reduced fertility that a...Hybridization is a creative evolutionary force,increasing genomic diversity and facilitating adaptation and even speciation.Hybrids often face significant challenges to establishment,including reduced fertility that arises from genomic incompatibilities between their parents.Whole-genome duplication in hybrids(allopolyploidy)can restore fertility,cause immediate phenotypic changes,and generate reproductive isolation.Yet the survival of polyploid lineages is uncertain,and few studies have compared the performance of recently formed allopolyploids and their parents under field conditions.Here,we use natural and synthetically produced hybrid and polyploid monkeyflowers(Mimulus spp.)to study how polyploidy contributes to the fertility,reproductive isolation,phenotype,and performance of hybrids in the field.We find that polyploidization restores fertility and that allopolyploids are reproductively isolated from their parents.The phenotype of allopolyploids displays the classic gigas effect of whole-genome duplication,in which plants have larger organs and are slower to flower.Field experiments indicate that survival of synthetic hybrids before and after polyploidization is intermediate between that of the parents,whereas natural hybrids have higher survival than all other taxa.We conclude that hybridization and polyploidy can act as sources of genomic novelty,but adaptive evolution is key in mediating the establishment of young allopolyploid lineages.展开更多
文摘MicroRNAs (miRNAs) are small, non-coding and regulatory RNAs about 20 to 24 nucleotides long. Their conserved nature among the various organisms makes them a good source of new miRNAs discovery by comparative genomics approach. This study resulted in 34 miRNAs belonging to 21 families in ecological model plant Mimulus. All the miRNA families (mir 156, 157, 159, 160, 164, 172, 319, 393, 395, 397, 399, 400, 403, 417, 419, 472, 782, 854, 858, 867 and 2112) are found for the first time in Mimulus. The MIR-399 is found as precursor miRNA cluster with 4 mature sequences. All 34 miRNA precursors form stable minimum free energy stem loop structure as their orthologues form and the mature miRNAs reside in the stem portion of the stem loop structure. Twenty eight are from Mimulus guttatus and six miRNAs belong to Mimulus lewisii. Their targets consist of dihy-droflavonol-4-reductase, cycloidea-like protein, DNA-directed RNA polymerase II, maturase (matR) and transcription factors like;squamosa-promoter binding, MYB, palmate-like pentafoliata 1.
基金supported by a Plant Fellows Postdoctoral Fellowship to S.M.(FP7,Marie Curie Actions,COFUND-University of Stirling,2014–2016)The Carnegie Trust(Research Incentive Grant 70158)the Botanical Society of Britain and Ireland(BSBI-2015)to M.V.-M.
文摘Hybridization is a creative evolutionary force,increasing genomic diversity and facilitating adaptation and even speciation.Hybrids often face significant challenges to establishment,including reduced fertility that arises from genomic incompatibilities between their parents.Whole-genome duplication in hybrids(allopolyploidy)can restore fertility,cause immediate phenotypic changes,and generate reproductive isolation.Yet the survival of polyploid lineages is uncertain,and few studies have compared the performance of recently formed allopolyploids and their parents under field conditions.Here,we use natural and synthetically produced hybrid and polyploid monkeyflowers(Mimulus spp.)to study how polyploidy contributes to the fertility,reproductive isolation,phenotype,and performance of hybrids in the field.We find that polyploidization restores fertility and that allopolyploids are reproductively isolated from their parents.The phenotype of allopolyploids displays the classic gigas effect of whole-genome duplication,in which plants have larger organs and are slower to flower.Field experiments indicate that survival of synthetic hybrids before and after polyploidization is intermediate between that of the parents,whereas natural hybrids have higher survival than all other taxa.We conclude that hybridization and polyploidy can act as sources of genomic novelty,but adaptive evolution is key in mediating the establishment of young allopolyploid lineages.
