PT  - JOURNAL ARTICLE
AU  - Joseph Heras
AU  - Mahul Chakraborty
AU  - J.J. Emerson
AU  - Donovan P. German
TI  - Physiological genomics of dietary adaptation in a marine herbivorous fish
AID  - 10.1101/457705
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 457705
4099  - http://biorxiv.org/content/early/2018/10/31/457705.short
4100  - http://biorxiv.org/content/early/2018/10/31/457705.full
AB  - Adopting a new diet is a significant evolutionary change and can profoundly affect an animal’s physiology, biochemistry, ecology, and its genome. To study this evolutionary transition, we investigated the physiology and genomics of digestion of a derived herbivorous fish, the monkeyface prickleback (Cebidichthys violaceus). We sequenced and assembled its genome and digestive transcriptome and revealed the molecular changes related to important dietary enzymes, finding abundant evidence for adaptation at the molecular level. In this species, two gene families experienced expansion in copy number and adaptive amino acid substitutions. These families, amylase, and bile salt activated lipase, are involved digestion of carbohydrates and lipids, respectively. Both show elevated levels of gene expression and increased enzyme activity. Because carbohydrates are abundant in the prickleback’s diet and lipids are rare, these findings suggest that such dietary specialization involves both exploiting abundant resources and scavenging rare ones, especially essential nutrients, like essential fatty acids.