Project description:The domesticated rock pigeon (Columba livia) has been bred for hundreds of years to display an immense variety of ornamental attributes such as feather color and color patterns. Color is influenced by multiple loci that impact the type and amount of melanin deposited on the feathers. Pigeons homozygous for the “recessive red” mutation, which causes downregulation of Sox10, display brilliant red feathers instead of blue/black feathers. Sox10 encodes a transcription factor important for melanocyte differentiation and function, but the genes that mediate its promotion of black vs. red pigment are unknown. Here, we present a transcriptomic comparison of regenerating feathers from wild-type and recessive red pigeons to identify candidate SOX10 targets. Our results identify both known and novel targets, including many genes not previously implicated in pigmentation. These data highlight the value of using novel, emerging model organisms to gain insight into the genetic basis of pigment variation.
Project description:<p>Pigeons (Columba livia) are widely kept as domesticated pets worldwide, and may have adapted to captivity through the evolutionarily specialized ability to produce ‘milk’ in the crops of both male and female parents via rapid proliferation and shedding of lipid- and protein-enriched epithelial cells. Given the implications for understanding evolution in atricial species, a comprehensive transcriptomic perspective of the pigeon crop spanning the complete breeding cycle is warranted. Here, we generated a de novo pigeon genome assembly to construct a high resolution spatio-temporal transcriptomic landscape of the crop epithelium across the entire breeding cycle. This multi-omics analysis identified a set of ‘lactation’-related genes involved in lipid and protein metabolism that are highly expressed in the crop. Spatial transcriptomics analysis revealed extensive reorganization of long-range promoter-enhancer interactions linked to the dynamic expression of these ‘lactation’-related genes between stages. Moreover, their expression is spatially localized in specific epithelial layers, and can be correlated with phenotypic changes in the crop. This study thus illustrates the preferential de novo synthesis of ‘milk’ lipids and proteins in the crop epithelium prior to shedding from the lumen, and provides candidate enhancer loci for further investigation of the regulatory elements controlling pigeon ‘lactation’. Furthermore, these comprehensive datasets provide a foundational resource for avian and evolutionary biology research, especially relevant to atricial reproductive biology.</p>