1. Innovation of heterochromatin functions drives rapid evolution of essential ZAD-ZNF genes in Drosophila .
- Author
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Kasinathan B, Colmenares SU 3rd, McConnell H, Young JM, Karpen GH, and Malik HS
- Subjects
- Animals, Drosophila Proteins genetics, Drosophila melanogaster genetics, Evolution, Molecular, Female, Genes, Insect genetics, Heterochromatin metabolism, Male, Phylogeny, Transcription Factors genetics, Drosophila Proteins physiology, Genes, Insect physiology, Heterochromatin physiology, Transcription Factors physiology
- Abstract
Contrary to dogma, evolutionarily young and dynamic genes can encode essential functions. We find that evolutionarily dynamic ZAD-ZNF genes, which encode the most abundant class of insect transcription factors, are more likely to encode essential functions in Drosophila melanogaster than ancient, conserved ZAD-ZNF genes. We focus on the Nicknack ZAD-ZNF gene, which is evolutionarily young, poorly retained in Drosophila species, and evolves under strong positive selection. Yet we find that it is necessary for larval development in D. melanogaster. We show that Nicknack encodes a heterochromatin-localizing protein like its paralog Oddjob , also an evolutionarily dynamic yet essential ZAD-ZNF gene. We find that the divergent D. simulans Nicknack protein can still localize to D. melanogaster heterochromatin and rescue viability of female but not male Nicknack- null D. melanogaster . Our findings suggest that innovation for rapidly changing heterochromatin functions might generally explain the essentiality of many evolutionarily dynamic ZAD-ZNF genes in insects., Competing Interests: BK, SC, HM, JY, GK, HM No competing interests declared, (© 2020, Kasinathan et al.)
- Published
- 2020
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