The article discusses ultraconserved elements (UCEs) in the human genome, which are segments of DNA that are highly conserved across multiple species, including humans, mice, rats, chickens, and dogs. These UCEs are typically longer than 200 bp and exhibit 100% identity with no insertions or deletions. The study identifies 481 such UCEs, most of which are also conserved in fish genomes. These elements are often located near genes involved in RNA processing, transcription regulation, and development. The authors find that UCEs exhibit very low levels of variation within the human population and across species, suggesting they are under strong negative selection. They are also enriched in clusters near transcription factors and developmental genes. The functional analysis reveals that exonic UCEs are associated with RNA processing and splicing, while non-exonic UCEs are linked to transcription regulation and DNA binding. The study suggests that these UCEs may play crucial roles in the ontogeny and physiology of vertebrates, possibly through the formation of RNA structures or regulatory networks.The article discusses ultraconserved elements (UCEs) in the human genome, which are segments of DNA that are highly conserved across multiple species, including humans, mice, rats, chickens, and dogs. These UCEs are typically longer than 200 bp and exhibit 100% identity with no insertions or deletions. The study identifies 481 such UCEs, most of which are also conserved in fish genomes. These elements are often located near genes involved in RNA processing, transcription regulation, and development. The authors find that UCEs exhibit very low levels of variation within the human population and across species, suggesting they are under strong negative selection. They are also enriched in clusters near transcription factors and developmental genes. The functional analysis reveals that exonic UCEs are associated with RNA processing and splicing, while non-exonic UCEs are linked to transcription regulation and DNA binding. The study suggests that these UCEs may play crucial roles in the ontogeny and physiology of vertebrates, possibly through the formation of RNA structures or regulatory networks.