학술논문
Genetic mapping of craniofacial traits in the Mexican tetra reveals loci associated with bite differences between cave and surface fish
Document Type
Academic Journal
Author
Source
BMC Ecology and Evolution. August 25, 2023, Vol. 23 Issue 1
Subject
Language
English
ISSN
2730-7182
Abstract
Author(s): Amanda K. Powers[sup.1], Carole Hyacinthe[sup.1], Misty R. Riddle[sup.2], Young Kwang Kim[sup.3], Alleigh Amaismeier[sup.4], Kathryn Thiel[sup.4], Brian Martineau[sup.1], Emma Ferrante[sup.1], Rachel L. Moran[sup.5], Suzanne E. McGaugh[sup.6], Tyler E. Boggs[sup.7], Joshua [...]
Background The Mexican tetra, Astyanax mexicanus, includes interfertile surface-dwelling and cave-dwelling morphs, enabling powerful studies aimed at uncovering genes involved in the evolution of cave-associated traits. Compared to surface fish, cavefish harbor several extreme traits within their skull, such as a protruding lower jaw, a wider gape, and an increase in tooth number. These features are highly variable between individual cavefish and even across different cavefish populations. Results To investigate these traits, we created a novel feeding behavior assay wherein bite impressions could be obtained. We determined that fish with an underbite leave larger bite impressions with an increase in the number of tooth marks. Capitalizing on the ability to produce hybrids from surface and cavefish crosses, we investigated genes underlying these segregating orofacial traits by performing Quantitative Trait Loci (QTL) analysis with F.sub.2 hybrids. We discovered significant QTL for bite (underbite vs. overbite) that mapped to a single region of the Astyanax genome. Within this genomic region, multiple genes exhibit coding region mutations, some with known roles in bone development. Further, we determined that there is evidence that this genomic region is under natural selection. Conclusions This work highlights cavefish as a valuable genetic model for orofacial patterning and will provide insight into the genetic regulators of jaw and tooth development. Keywords: Jaws, Teeth, Feeding behavior, Quantitative trait loci, Cavefish
Background The Mexican tetra, Astyanax mexicanus, includes interfertile surface-dwelling and cave-dwelling morphs, enabling powerful studies aimed at uncovering genes involved in the evolution of cave-associated traits. Compared to surface fish, cavefish harbor several extreme traits within their skull, such as a protruding lower jaw, a wider gape, and an increase in tooth number. These features are highly variable between individual cavefish and even across different cavefish populations. Results To investigate these traits, we created a novel feeding behavior assay wherein bite impressions could be obtained. We determined that fish with an underbite leave larger bite impressions with an increase in the number of tooth marks. Capitalizing on the ability to produce hybrids from surface and cavefish crosses, we investigated genes underlying these segregating orofacial traits by performing Quantitative Trait Loci (QTL) analysis with F.sub.2 hybrids. We discovered significant QTL for bite (underbite vs. overbite) that mapped to a single region of the Astyanax genome. Within this genomic region, multiple genes exhibit coding region mutations, some with known roles in bone development. Further, we determined that there is evidence that this genomic region is under natural selection. Conclusions This work highlights cavefish as a valuable genetic model for orofacial patterning and will provide insight into the genetic regulators of jaw and tooth development. Keywords: Jaws, Teeth, Feeding behavior, Quantitative trait loci, Cavefish