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The microRNA toolkit of insects

View Article: PubMed Central - PubMed

ABSTRACT

Is there a correlation between miRNA diversity and levels of organismic complexity? Exhibiting extraordinary levels of morphological and developmental complexity, insects are the most diverse animal class on earth. Their evolutionary success was in particular shaped by the innovation of holometabolan metamorphosis in endopterygotes. Previously, miRNA evolution had been linked to morphological complexity, but astonishing variation in the currently available miRNA complements of insects made this link unclear. To address this issue, we sequenced the miRNA complement of the hemimetabolan Blattella germanica and reannotated that of two other hemimetabolan species, Locusta migratoria and Acyrthosiphon pisum, and of four holometabolan species, Apis mellifera, Tribolium castaneum, Bombyx mori and Drosophila melanogaster. Our analyses show that the variation of insect miRNAs is an artefact mainly resulting from poor sampling and inaccurate miRNA annotation, and that insects share a conserved microRNA toolkit of 65 families exhibiting very low variation. For example, the evolutionary shift toward a complete metamorphosis was accompanied only by the acquisition of three and the loss of one miRNA families.

No MeSH data available.


Gains and losses of miRNA families during cladogenesis of the seven species studied.The phylogenetic tree is based on Misof et al.21. The number of conserved miRNA families is shown besides the name of each species.
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f6: Gains and losses of miRNA families during cladogenesis of the seven species studied.The phylogenetic tree is based on Misof et al.21. The number of conserved miRNA families is shown besides the name of each species.

Mentions: Most of the conserved miRNAs come from an ancestral complement of 62 miRNA families accumulated from the emergence of eumetazoans until the hexapodan last common ancestor (Fig. 4). We considered MIR-bg5 family in this complement, as it is present in the polyneopterans B. germanica and L. migratoria, and the paraneopteran A. pisum, although it is absent in the endopterygotes A. mellifera, T. castaneum, B. mori and D. melanogaster. Thus, according the more robust phylogenetic reconstruction available21, it is more parsimonious to hypothesize a loss of MIR-bg5 in the endopterygotes than two independent gains in polyneopterans and paraneopterans. From these 62 miRNA families, it is apparent the loss of MIR-309 in the branch leading to the paraneopteran A. pisum. Then, one miRNA family appears lost in B. germanica and four in L. migratoria (Fig. 6). No apparent changes are observed in the node clustering paraneopterans and endopterygotes, but 10 miRNA family losses can be recorded in the branch leading to A. pisum.


The microRNA toolkit of insects
Gains and losses of miRNA families during cladogenesis of the seven species studied.The phylogenetic tree is based on Misof et al.21. The number of conserved miRNA families is shown besides the name of each species.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5121899&req=5

f6: Gains and losses of miRNA families during cladogenesis of the seven species studied.The phylogenetic tree is based on Misof et al.21. The number of conserved miRNA families is shown besides the name of each species.
Mentions: Most of the conserved miRNAs come from an ancestral complement of 62 miRNA families accumulated from the emergence of eumetazoans until the hexapodan last common ancestor (Fig. 4). We considered MIR-bg5 family in this complement, as it is present in the polyneopterans B. germanica and L. migratoria, and the paraneopteran A. pisum, although it is absent in the endopterygotes A. mellifera, T. castaneum, B. mori and D. melanogaster. Thus, according the more robust phylogenetic reconstruction available21, it is more parsimonious to hypothesize a loss of MIR-bg5 in the endopterygotes than two independent gains in polyneopterans and paraneopterans. From these 62 miRNA families, it is apparent the loss of MIR-309 in the branch leading to the paraneopteran A. pisum. Then, one miRNA family appears lost in B. germanica and four in L. migratoria (Fig. 6). No apparent changes are observed in the node clustering paraneopterans and endopterygotes, but 10 miRNA family losses can be recorded in the branch leading to A. pisum.

View Article: PubMed Central - PubMed

ABSTRACT

Is there a correlation between miRNA diversity and levels of organismic complexity? Exhibiting extraordinary levels of morphological and developmental complexity, insects are the most diverse animal class on earth. Their evolutionary success was in particular shaped by the innovation of holometabolan metamorphosis in endopterygotes. Previously, miRNA evolution had been linked to morphological complexity, but astonishing variation in the currently available miRNA complements of insects made this link unclear. To address this issue, we sequenced the miRNA complement of the hemimetabolan Blattella germanica and reannotated that of two other hemimetabolan species, Locusta migratoria and Acyrthosiphon pisum, and of four holometabolan species, Apis mellifera, Tribolium castaneum, Bombyx mori and Drosophila melanogaster. Our analyses show that the variation of insect miRNAs is an artefact mainly resulting from poor sampling and inaccurate miRNA annotation, and that insects share a conserved microRNA toolkit of 65 families exhibiting very low variation. For example, the evolutionary shift toward a complete metamorphosis was accompanied only by the acquisition of three and the loss of one miRNA families.

No MeSH data available.