Growth factor gene IGF1 is associated with bill size in the black-bellied seedcracker Pyrenestes ostrinus.

TitleGrowth factor gene IGF1 is associated with bill size in the black-bellied seedcracker Pyrenestes ostrinus.
Publication TypeJournal Article
Year of Publication2018
AuthorsvonHoldt, BM, Kartzinel, RY, Huber, CD, Le Underwood, V, Zhen, Y, Ruegg, K, Lohmueller, KE, Smith, TB
JournalNat Commun
Volume9
Issue1
Pagination4855
Date Published2018 11 19
ISSN2041-1723
KeywordsAnimals, Beak, Biological Evolution, Eating, Finches, Gene Expression, Haplotypes, Hardness, Insulin-Like Growth Factor I, Linkage Disequilibrium, Organ Size, Phenotype, Polymorphism, Genetic, Seeds, Selection, Genetic, Whole Genome Sequencing
Abstract

Pyrenestes finches are unique among birds in showing a non-sex-determined polymorphism in bill size and are considered a textbook example of disruptive selection. Morphs breed randomly with respect to bill size, and differ in diet and feeding performance relative to seed hardness. Previous breeding experiments are consistent with the polymorphism being controlled by a single genetic factor. Here, we use genome-wide pooled sequencing to explore the underlying genetic basis of bill morphology and identify a single candidate region. Targeted resequencing reveals extensive linkage disequilibrium across a 300 Kb region containing the insulin-like growth factor 1 (IGF1) gene, with a single 5-million-year-old haplotype associating with phenotypic dominance of the large-billed morph. We find no genetic similarities controlling bill size in the well-studied Darwin's finches (Geospiza). Our results show how a single genetic factor may control bill size and provide a foundation for future studies to examine this phenomenon within and among avian species.

DOI10.1038/s41467-018-07374-9
Alternate JournalNat Commun
PubMed ID30451848
PubMed Central IDPMC6242981
Grant ListS10 OD018174 / OD / NIH HHS / United States