A draft reference genome assembly of California Pipevine, Aristolochia californica Torr.

The California Pipevine, Aristolochia californica Torr., is the only endemic California species within the cosmopolitan birthwort family Aristolochiaceae. It occurs as an understory vine in riparian and chaparral areas and in forest edges and windrows. The geographic range of this plant species almost entirely overlaps with that of its major specialized herbivore, the California Pipevine Swallowtail Butterfly Battus philenor hirsuta. While this species pair is a useful, ecologically well-understood system to study co-evolution, until recently, genomic resources for both have been lacking. Here, we report a new, chromosome-level assembly of A. californica as part of the California Conservation Genomics Project (CCGP). Following the sequencing and assembly strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin proximity sequencing technology to produce a de novo assembled genome. Our genome assembly, the first for any species in the genus, contains 531 scaffolds spanning 661 megabase (Mb) pairs, with a contig N50 of 6.53 Mb, a scaffold N50 of 42.2 Mb, and BUSCO complete score of 98%. In combination with the recently published B. philenor hirsuta reference genome assembly, the A. californica reference genome assembly will be a powerful tool for studying co-evolution in a rapidly changing California landscape.

A highly contiguous genome assembly for the Yellow Warbler (Setophaga petechia).

The Yellow Warbler (Setophaga petechia) is a small songbird in the wood-warbler family (Parulidae) that exhibits phenotypic and ecological differences across a widespread distribution and is important to California's riparian habitat conservation. Here, we present a high-quality de novo genome assembly of a vouchered female Yellow Warbler from southern California. Using HiFi long-read and Omni-C proximity sequencing technologies, we generated a 1.22 Gb assembly including 687 scaffolds with a contig N50 of 6.80 Mb, scaffold N50 of 21.18 Mb, and a BUSCO completeness score of 96.0%. This highly contiguous genome assembly provides an essential resource for understanding the history of gene flow, divergence, and local adaptation in Yellow Warblers and can inform conservation management of this charismatic bird species.

A genome assembly of the Yuma myotis bat, Myotis yumanensis.

The Yuma myotis bat (Myotis yumanensis) is a small vespertilionid bat and one of 52 species of new world Myotis bats in the subgenus Pizonyx. While M. yumanensis populations currently appear relatively stable, it is one of 12 bat species known or suspected to be susceptible to white-nose syndrome, the fungal disease causing declines in bat populations across North America. Only two of these 12 species have genome resources available, which limits the ability of resource managers to use genomic techniques to track the responses of bat populations to white-nose syndrome generally. Here we present the first de novo genome assembly for Yuma myotis, generated as a part of the California Conservation Genomics Project. The M. yumanensis genome was generated using a combination of PacBio HiFi long reads and Omni-C chromatin-proximity sequencing technology. This high-quality genome is one of the most complete bat assemblies available, with a contig N50 of 28.03 Mb, scaffold N50 of 99.14 Mb, and BUSCO completeness score of 93.7%. The Yuma myotis genome provides a high-quality resource that will aid in comparative genomic and evolutionary studies, as well as inform conservation management related to white-nose syndrome.

The reference genome assembly of the bright cobblestone lichen, Acarospora socialis.

Acarospora socialis, the bright cobblestone lichen, is commonly found in southwestern North America. This charismatic yellow lichen is a species of key ecological significance as it is often a pioneer species in new environments. Despite their ecological importance virtually no research has been conducted on the genomics of A. socialis. To address this, we used long-read sequencing to generate the first high-quality draft genome of A. socialis. Lichen thallus tissue was collected from Pinkham Canyon in Joshua Tree National Park, California and deposited in the UC Riverside herbarium under accession #295874. The de novo assembly of the mycobiont partner of the lichen was generated from Pacific Biosciences HiFi long reads and Dovetail Omni-C chromatin capture data. After removing algal and bacterial contigs, the fungal genome was approximately 31.2 Mb consisting of 38 scaffolds with contig and scaffold N50 of 2.4 Mb. The BUSCO completeness score of the assembled genome was 97.5% using the Ascomycota gene set. Information on the genome of A. socialis is important for California conservation purposes given that this lichen is threatened in some places locally by wildfires due to climate change. This reference genome will be used for understanding the genetic diversity, population genomics, and comparative genomics of A. socialis species. Genomic resources for this species will support population and landscape genomics investigations, exploring the use of A. socialis as a bioindicator species for climate change, and in studies of adaptation by comparing populations that occur across aridity gradients in California.

De novo assembly of a chromosome-level reference genome for the California Scrub-Jay, Aphelocoma californica.

We announce the assembly of the first de novo reference genome for the California Scrub-Jay (Aphelocoma californica). The genus Aphelocoma comprises four currently recognized species including many locally adapted populations across Mesoamerica and North America. Intensive study of Aphelocoma has revealed novel insights into the evolutionary mechanisms driving diversification in natural systems. Additional insights into the evolutionary history of this group will require continued development of high-quality, publicly available genomic resources. We extracted high molecular weight genomic DNA from a female California Scrub-Jay from northern California and generated PacBio HiFi long-read data and Omni-C chromatin conformation capture data. We used these data to generate a de novo partially phased diploid genome assembly, consisting of two pseudo-haplotypes, and scaffolded them using inferred physical proximity information from the Omni-C data. The more complete pseudo-haplotype assembly (arbitrarily designated "Haplotype 1") is 1.35 Gb in total length, highly contiguous (contig N50 = 11.53 Mb), and highly complete (BUSCO completeness score = 97%), with comparable scaffold sizes to chromosome-level avian reference genomes (scaffold N50 = 66.14 Mb). Our California Scrub-Jay assembly is highly syntenic with the New Caledonian Crow reference genome despite ~10 million years of divergence, highlighting the temporal stability of the avian genome. This high-quality reference genome represents a leap forward in publicly available genomic resources for Aphelocoma, and the family Corvidae more broadly. Future work using Aphelocoma as a model for understanding the evolutionary forces generating and maintaining biodiversity across phylogenetic scales can now benefit from a highly contiguous, in-group reference genome.

A draft reference genome assembly of the Pipevine Swallowtail butterfly, Battus philenor hirsuta.

The California Pipevine Swallowtail Butterfly, Battus philenor hirsuta, and its host plant, the California Pipevine or Dutchman's Pipe, Aristolochia californica Torr., are an important California endemic species pair. While this species pair is an ideal system to study co-evolution, genomic resources for both are lacking. Here, we report a new, chromosome-level assembly of B. philenor hirsuta as part of the California Conservation Genomics Project (CCGP). Following the sequencing and assembly strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin proximity sequencing technology to produce a de novo assembled genome. Our genome assembly, the first for any species in the genus, contains 109 scaffolds spanning 443 mega base (Mb) pairs, with a contig N50 of 14.6 Mb, a scaffold N50 of 15.2 Mb, and BUSCO complete score of 98.9%. In combination with the forthcoming A. californica reference genome, the B. philenor hirsuta genome will be a powerful tool for documenting landscape genomic diversity and plant-insect co-evolution in a rapidly changing California landscape.

Reference genome of the rubber boa, Charina bottae (Serpentes: Boidae).

The rubber boa, Charina bottae is a semi-fossorial, cold-temperature adapted snake that ranges across the wetter and cooler ecoregions of the California Floristic Province. The rubber boa is 1 of 2 species in the family Boidae native to California and currently has 2 recognized subspecies, the Northern rubber boa C. bottae bottae and the Southern rubber boa C. bottae umbratica. Recent genomic work on C. bottae indicates that these 2 subspecies are collectively composed of 4 divergent lineages that separated during the late Miocene. Analysis of habitat suitability indicates that C. bottae umbratica montane sky-island populations from southern California will lose the majority of their habit over the next 70 yr, and is listed as Threatened under the California Endangered Species Act. Here, we report a new, chromosome-level assembly of C. bottae bottae as part of the California Conservation Genomics Project (CCGP). Consistent with the reference genome strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises 289 scaffolds covering 1,804,944,895 bp, has a contig N50 of 37.3 Mb, a scaffold N50 of 97 Mb, and BUSCO completeness score of 96.3%, and represents the first reference genome for the Boidae snake family. This genome will enable studies of genetic differentiation and connectivity among C. bottae bottae and C. bottae umbratica populations across California and help manage locally endemic lineages as they confront challenges from human-induced climate warming, droughts, and wildfires across California.

Reference genome of the color polymorphic desert annual plant sandblossoms, Linanthus parryae.

Sandblossoms, Linanthus parryae is a widespread annual plant species found in washes and sandy open habitats across the Mojave Desert and Eastern Sierra Nevada of California. Studies in this species have played a central role in evolutionary biology, serving as the first test cases of the shifting balance theory of evolution, models of isolation by distance, and metrics to describe the genetic structure of natural populations. Despite the importance of L. parryae in the development of landscape genetics and phylogeography, there are no genomic resources available for the species. Through the California Conservation Genomics Project, we assembled the first genome in the genus Linanthus. Using PacBio HiFi long reads and Hi-C chromatin conformation capture, we assembled 123 scaffolds spanning 1.51 Gb of the 1.96 Gb estimated genome, with a contig N50 of 18.7 Mb and a scaffold N50 of 124.8 Mb. This assembly, with a BUSCO completeness score of 88.7%, will allow us to revisit foundational ideas central to our understanding of how evolutionary forces operate in a geographic landscape. In addition, it will be a new resource to uncover adaptations to arid environments in the fragile desert habitat threatened by urban and solar farm development, climate change, and off-road vehicles.