The Strength of Selection on Ultraconserved Elements in the Human Genome

摘要: Ultraconserved elements are stretches of consecutive nucleotides that perfectly conserved in multiple mammalian genomes. Although these sequences identical the reference human, mouse, and rat genomes, we identified numerous polymorphisms within regions human population. To determine whether ultraconserved affect fitness, genotyped unrelated DNA samples at loci sequences. For all single-nucleotide tested regions, individuals homozygous for derived alleles (alleles differ from rodent genomes) were present, viable, healthy. The distribution allele frequencies argues against strong, ongoing selection as force maintaining conservation We then used two methods to minimum level required generate Despite lack fixed differences between humans rodents, average on is less than essential genes. strength associated with suggests mutations may have subtle phenotypic consequences not easily detected laboratory.