The evolution and genetic basis of a functionally critical skull bone, the parasphenoid, among Lake Malawi cichlids.

Adaptive radiation, whereby a clade pairs rapid speciation with rapid phenotypic evolution, can result in an uneven distribution of biodiversity across the Metazoan tree. The cichlid fishes of East Africa have undergone multiple adaptive radiations within the major rift lakes. Cichlid radiations are marked by divergence across distinct habitat gradients producing many morphological and behavioural adaptations.

Variable Craniofacial Shape and Development among Multiple Cave-Adapted Populations of .

is a freshwater fish species with blind cave morphs and sighted surface morphs. Like other troglodytic species, independently evolved cave-dwelling populations share several stereotypic phenotypes, including the expansion of certain sensory systems, as well as the loss of eyes and pigmentation. Here, we assess the extent to which there is also parallelism in craniofacial development across cave populations.

Foraging-induced craniofacial plasticity is associated with an early, robust and dynamic transcriptional response.

Phenotypic plasticity is the ability of a single genotype to vary its phenotype in response to the environment. Plasticity of the skeletal system in response to mechanical input is widely studied, but the timing of its transcriptional regulation is not well understood. Here, we used the cichlid feeding apparatus to examine the transcriptional dynamics of skeletal plasticity over time.

The transcriptional state and chromatin landscape of cichlid jaw shape variation across species and environments.

Adaptive phenotypes are shaped by a combination of genetic and environmental forces, but how they interact remains poorly understood. Here, we utilize the cichlid oral jaw apparatus to better understand these gene-by-environment effects. First, we employed RNA-seq in bony and ligamentous tissues important for jaw opening to identify differentially expressed genes between species and across foraging environments.

Zebrafish crocc2 mutants exhibit divergent craniofacial shape, misregulated variability, and aberrant cartilage morphogenesis.

Background: Phenotypic variation is of paramount importance in development, evolution, and human health; however, the molecular mechanisms that influence organ shape and shape variability are not well understood. During craniofacial development, the behavior of skeletal precursors is regulated by both biochemical and environmental inputs, and the primary cilia play critical roles in transducing both types of signals. Here, we examine a gene that encodes a key constituent of the ciliary rootlets, crocc2, and its role in cartilage morphogenesis in larval zebrafish.