Appetite regulating genes may contribute to herbivory versus carnivory trophic divergence in haplochromine cichlids

PeerJ

article

Ehsan P. Ahi¹  Anna Duenser²  Pooja Singh²  Wolfgang Gessl²  Christian Sturmbauer² 

[1] Evolutionary Biology Centre, Uppsala University;Institute of Biology, University of Graz;Institute of Biological Sciences, University of Calgary

关键词: Appetite regulation;    East African Lakes;    Cichlids;    Gene expression;    Trophic specialization;    Adaptive radiation;    Anorexigenic;    Orexigenic;    Brain;    Larval development;   

DOI  :  10.7717/peerj.8375

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Feeding is a complex behaviour comprised of satiety control, foraging, ingestion and subsequent digestion. Cichlids from the East African Great Lakes are renowned for their diverse trophic specializations, largely predicated on highly variable jaw morphologies. Thus, most research has focused on dissecting the genetic, morphological and regulatory basis of jaw and teeth development in these species. Here for the first time we explore another aspect of feeding, the regulation of appetite related genes that are expressed in the brain and control satiety in cichlid fishes. Using qPCR analysis, we first validate stably expressed reference genes in the brain of six haplochromine cichlid species at the end of larval development prior to foraging. We next evaluate the expression of 16 appetite related genes in herbivorous and carnivorous species from the parallel radiations of Lake Tanganyika, Malawi and Victoria. Interestingly, we find increased expression of two appetite-regulating genes (anorexigenic genes), cart and npy2r, in the brain of carnivorous species in all the three lakes. This supports the notion that appetite gene regulation might play a part in determining trophic niche specialization in divergent cichlid species, already prior to exposure to different diets. Our study contributes to the limited body of knowledge on the neurological circuitry that controls feeding transitions and adaptations in cichlids and other teleosts.

【 授权许可】

CC BY