Z-DNA is a high-energy alternative conformation of the DNA double helix in which it has potential roles in gene expression, DNA damage and repair, and implications in certain disease processes. Z-DNA forming sequences are not evenly distributed across the genomes, and their density can vary widely among different organisms based on their genomic complexities and evolutionary histories. In avian genomes, which are generally more compact compared to mammals, the information on Z-DNA density has not been well delineated yet. Here, we applied a predictive tool to estimate Z-DNA forming regions in 79 avian genomes and utilized global datasets of the physiological, anatomical, ecological, and geographical characteristics of birds. We showed that the density of Z-DNA is correlated with body mass and flight efficiency. This study may provide insights into the density and biological roles of this alternate DNA structure across different vertebrates.
The density of Z-DNA may be correlated with some phenotypic attributes in birds