As the field of comparative genomics rapidly expands, along with wider availability of deep sequencing, more and more plant and animal genomes are being sequenced and mapped. As a result, the number of fully mapped genomes is rapidly multiplying, for both current and extinct species.
In this past week, comparative analyses of several dog and wolf genomes from different
altitudes in close geographic proximity were evaluated for similarity. While the Tibetan Mastiff was much more closely related to dogs than wolves on a genome-wide scale, several genomic regions were identified that possibly introgressed from Tibetan grey wolf, which may have ultimately aided its adaptation to the extreme highland environment.
Meanwhile, the Far Eastern Amur leopard was sequenced to create a de novo assembly that spanned almost 2.6 billion base pairs and contained 19,043 predicted protein-coding genes. Following genome assembly, the Far Eastern Amur leopard was compared to 18 genomes including domestic cat, tiger, lion, cheetah, and leopard. Comparative analysis between carnivores, omnivores and herbivores identified differences in genomic content: in addition to a reduction gene families for starch and sucrose metabolism, the carnivore genomes showed evidence of shared evolutionary adaptations in genes associated with diet, muscle strength, agility, and other traits responsible for successful hunting and meat consumption.
Finally, comparative genomics between the modern human genome and the extinct Neanderthals revealed the strength of selection against Neanderthal introgression in the human genome. Humans and Neanderthals interbred some 50,000 years ago, but only about 1-2% of modern human genomes have Neanderthal-origin DNA. Failure of introgression may be attributable to low genetic diversity and effective population size: while weakly deleterious alleles may be neutral in the smaller Neanderthal population, they could have a much more profound effect in the larger human population and thus were selected against.
As with all genomic analysis, sequencing is only the first step towards comprehensive understanding. Copy number analysis on these genomes will undoubtedly reveal additional information. As a reminder, ANY organism with a mapped genome can be analyzed for copy number analysis using Nexus Copy Number.