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Different yet similar: evolution of imprinting in flowering plants and mammals.

Pires ND, Grossniklaus U - F1000Prime Rep (2014)

Bottom Line: In both groups, imprinted expression is controlled, at least in part, by DNA methylation and chromatin modifications in cis-regulatory regions, and many maternally and paternally expressed genes display complementary dosage-dependent effects during embryogenesis.There is a large degree of intra- and inter-specific variation in imprinted gene expression in plants.These differences likely reflect the distinct life cycles and the different evolutionary dynamics that shape plant and animal genomes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Biology & Zürich-Basel Plant Science Center, University of Zürich Zollikerstrasse 107, CH-8008 Zürich Switzerland.

ABSTRACT
Genomic imprinting refers to a form of epigenetic gene regulation whereby alleles are differentially expressed in a parent-of-origin-dependent manner. Imprinting evolved independently in flowering plants and in therian mammals in association with the elaboration of viviparity and a placental habit. Despite the striking differences in plant and animal reproduction, genomic imprinting shares multiple characteristics between them. In both groups, imprinted expression is controlled, at least in part, by DNA methylation and chromatin modifications in cis-regulatory regions, and many maternally and paternally expressed genes display complementary dosage-dependent effects during embryogenesis. This suggests that genomic imprinting evolved in response to similar selective pressures in flowering plants and mammals. Nevertheless, there are important differences between plant and animal imprinting. In particular, genomic imprinting has been shown to be more flexible and evolutionarily labile in plants. In mammals, imprinted genes are organized mainly in highly conserved clusters, whereas in plants they occur in isolation throughout the genome and are affected by local gene duplications. There is a large degree of intra- and inter-specific variation in imprinted gene expression in plants. These differences likely reflect the distinct life cycles and the different evolutionary dynamics that shape plant and animal genomes.

No MeSH data available.


Timescale for the evolution of imprinting in animals and plants
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fig-001: Timescale for the evolution of imprinting in animals and plants

Mentions: The term “imprinting” was coined to describe the selective marking and elimination of all paternal chromosomes in sciarid insects [17]. Here, however, we consider only genomic imprinting that affects individual genes or gene clusters rather than entire chromosomes or genomes. In animals, genomic imprinting of individual genes has been identified in eutherian and marsupial mammals but not in monotremes or in non-mammalian vertebrates, such as birds [18,19]. This suggests that the evolution of genomic imprinting was associated with the elaboration of viviparity in the common ancestor of all therian mammals, which lived in the Jurassic period, 160 to 200 million years ago [20,21] (Figure 1). In plants, genomic imprinting has been identified in the endosperm and embryo—the two products of double fertilization—of monocots and eudicots (reviewed in [1,15]) but has not been reported in non-flowering plants, likely due to a lack of experimental investigation. These findings suggest that imprinting evolved in association with the evolution of the endosperm (an embryo-nourishing tissue) in the Early Cretaceous, 100 to 145 million years ago [22] (Figure 1).


Different yet similar: evolution of imprinting in flowering plants and mammals.

Pires ND, Grossniklaus U - F1000Prime Rep (2014)

Timescale for the evolution of imprinting in animals and plants
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126536&req=5

fig-001: Timescale for the evolution of imprinting in animals and plants
Mentions: The term “imprinting” was coined to describe the selective marking and elimination of all paternal chromosomes in sciarid insects [17]. Here, however, we consider only genomic imprinting that affects individual genes or gene clusters rather than entire chromosomes or genomes. In animals, genomic imprinting of individual genes has been identified in eutherian and marsupial mammals but not in monotremes or in non-mammalian vertebrates, such as birds [18,19]. This suggests that the evolution of genomic imprinting was associated with the elaboration of viviparity in the common ancestor of all therian mammals, which lived in the Jurassic period, 160 to 200 million years ago [20,21] (Figure 1). In plants, genomic imprinting has been identified in the endosperm and embryo—the two products of double fertilization—of monocots and eudicots (reviewed in [1,15]) but has not been reported in non-flowering plants, likely due to a lack of experimental investigation. These findings suggest that imprinting evolved in association with the evolution of the endosperm (an embryo-nourishing tissue) in the Early Cretaceous, 100 to 145 million years ago [22] (Figure 1).

Bottom Line: In both groups, imprinted expression is controlled, at least in part, by DNA methylation and chromatin modifications in cis-regulatory regions, and many maternally and paternally expressed genes display complementary dosage-dependent effects during embryogenesis.There is a large degree of intra- and inter-specific variation in imprinted gene expression in plants.These differences likely reflect the distinct life cycles and the different evolutionary dynamics that shape plant and animal genomes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Biology & Zürich-Basel Plant Science Center, University of Zürich Zollikerstrasse 107, CH-8008 Zürich Switzerland.

ABSTRACT
Genomic imprinting refers to a form of epigenetic gene regulation whereby alleles are differentially expressed in a parent-of-origin-dependent manner. Imprinting evolved independently in flowering plants and in therian mammals in association with the elaboration of viviparity and a placental habit. Despite the striking differences in plant and animal reproduction, genomic imprinting shares multiple characteristics between them. In both groups, imprinted expression is controlled, at least in part, by DNA methylation and chromatin modifications in cis-regulatory regions, and many maternally and paternally expressed genes display complementary dosage-dependent effects during embryogenesis. This suggests that genomic imprinting evolved in response to similar selective pressures in flowering plants and mammals. Nevertheless, there are important differences between plant and animal imprinting. In particular, genomic imprinting has been shown to be more flexible and evolutionarily labile in plants. In mammals, imprinted genes are organized mainly in highly conserved clusters, whereas in plants they occur in isolation throughout the genome and are affected by local gene duplications. There is a large degree of intra- and inter-specific variation in imprinted gene expression in plants. These differences likely reflect the distinct life cycles and the different evolutionary dynamics that shape plant and animal genomes.

No MeSH data available.