TY  - JOUR
EP  - 12
UR  - https://doi.org/10.1371/journal.pgen.1004698
ID  - discovery10097257
N2  - Gene duplications within the conserved Hox cluster are rare in animal evolution, but in Lepidoptera an array of divergent Hox-related genes (Shx genes) has been reported between pb and zen. Here, we use genome sequencing of five lepidopteran species (Polygonia c-album, Pararge aegeria, Callimorpha dominula, Cameraria ohridella, Hepialus sylvina) plus a caddisfly outgroup (Glyphotaelius pellucidus) to trace the evolution of the lepidopteran Shx genes. We demonstrate that Shx genes originated by tandem duplication of zen early in the evolution of large clade Ditrysia; Shx are not found in a caddisfly and a member of the basally diverging Hepialidae (swift moths). Four distinct Shx genes were generated early in ditrysian evolution, and were stably retained in all descendent Lepidoptera except the silkmoth which has additional duplications. Despite extensive sequence divergence, molecular modelling indicates that all four Shx genes have the potential to encode stable homeodomains. The four Shx genes have distinct spatiotemporal expression patterns in early development of the Speckled Wood butterfly (Pararge aegeria), with ShxC demarcating the future sites of extraembryonic tissue formation via strikingly localised maternal RNA in the oocyte. All four genes are also expressed in presumptive serosal cells, prior to the onset of zen expression. Lepidopteran Shx genes represent an unusual example of Hox cluster expansion and integration of novel genes into ancient developmental regulatory networks.
IS  - 10
AV  - public
TI  - Ancient Expansion of the Hox Cluster in Lepidoptera Generated Four Homeobox Genes Implicated in Extra-Embryonic Tissue Formation
Y1  - 2014/10/23/
KW  - Homeobox
KW  -  Moths and butterflies
KW  -  Sequence motif analysis
KW  -  Evolutionary genetics
KW  -  Embryos
KW  -  Insects
KW  -  Phylogenetic analysis
KW  -  Oocytes
PB  - PUBLIC LIBRARY SCIENCE
JF  - PLOS Genetics
A1  - Ferguson, L
A1  - Marlétaz, F
A1  - Carter, J-M
A1  - Taylor, WR
A1  - Gibbs, M
A1  - Breuker, CJ
A1  - Holland, PWH
N1  - Copyright © 2014 Ferguson et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
VL  - 10
ER  -