RT Journal Article
SR Electronic
T1 Mutual regulation underlies paralogue functional diversification
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 427245
DO 10.1101/427245
A1 Daniela Gurska
A1 Iris M. Vargas Jentzsch
A1 Kristen A. Panfilio
YR 2019
UL http://biorxiv.org/content/early/2019/04/15/427245.abstract
AB To what extent can ancestral function be deduced from the current roles of duplicated genes? Insect Hox3/zen genes represent an evolutionary hotspot, with single orthologues required either for early specification or late morphogenesis of the extraembryonic tissues. The zen paralogues of the beetle Tribolium castaneum present a unique opportunity to investigate both functions in a single species. We show that despite high sequence similarity the paralogues’ expression dynamics (transcript and protein) and transcriptional targets (RNA-seq after RNAi) are non-redundant. Rather, we find that Tc-Zen2 represses Tc-zen1, producing an evolutionarily novel negative feedback loop that confers a high level of temporal precision to early specification. For late morphogenesis, our molecular profiling of Tc-Zen2 also uncovers a transcriptional delay and partial recovery that underpins the spectrum of morphological phenotypes. Altogether, our molecular dissection reveals that complementary roles and mutual regulation reinforce paralogue retention, implying an evolutionary scenario of iterative subfunctionalization.