Sarah M. Baty
Robert N. Fisher
Peter A. Scott
Greer A. Dolby
Adrian Munguia-Vega
Diego Cortez
Elizabeth Davalos-Dehullu
2023
<p class="chapter-para"><i>Urosaurus nigricaudus</i><span> </span>is a phrynosomatid lizard endemic to the Baja California Peninsula in Mexico. This work presents a chromosome-level genome assembly and annotation from a male individual. We used PacBio long reads and HiRise scaffolding to generate a high-quality genomic assembly of 1.87 Gb distributed in 327 scaffolds, with an N50 of 279 Mb and an L50 of 3. Approximately 98.4% of the genome is contained in 14 scaffolds, with 6 large scaffolds (334–127 Mb) representing macrochromosomes and 8 small scaffolds (63–22 Mb) representing microchromosomes. Using standard gene modeling and transcriptomic data, we predicted 17,902 protein-coding genes on the genome. The repeat content is characterized by a large proportion of long interspersed nuclear elements that are relatively old. Synteny analysis revealed some microchromosomes with high repeat content are more prone to rearrangements but that both macro- and microchromosomes are well conserved across reptiles. We identified scaffold 14 as the X chromosome. This microchromosome presents perfect dosage compensation where the single X of males has the same expression levels as two X chromosomes in females. Finally, we estimated the effective population size for<span> </span><i>U. nigricaudus</i><span> </span>was extremely low, which may reflect a reduction in polymorphism related to it becoming a peninsular endemic.</p>
application/pdf
10.1093/gbe/evad210
en
Oxford Academic
Chromosome-level genome assembly of the blacktail brush lizard, Urosaurus nigricaudus, reveals dosage compensation in an endemic lizard
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