Dataset Information

Whole-Genome Analysis of Introgression Between the Spotted Owl and Barred Owl (Strix occidentalis and Strix varia, Respectively; Aves: Strigidae) in Western North America.

ABSTRACT: As the barred owl (Strix varia; Aves: Strigiformes: Strigidae) expands throughout western North America, hybridization between barred and spotted owls (Strix varia and S. occidentalis, respectively), if abundant, may lead to genetic swamping of the endangered spotted owl. We analyzed low-coverage, whole-genome sequence data from fifty-one barred and spotted owls to investigate recent introgression between these two species. Although we obtained genomic confirmation that these species can and do hybridize and backcross, we found no evidence of widespread introgression. Plumage characteristics of western S. varia that suggested admixture with S. occidentalis appear unrelated to S. occidentalis ancestry and may instead reflect local selection.

SUBMITTER: Hanna ZR

PROVIDER: S-EPMC6288836 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Whole-Genome Analysis of Introgression Between the Spotted Owl and Barred Owl (Strix occidentalis and Strix varia, Respectively; Aves: Strigidae) in Western North America.

Hanna Zachary R ZR Dumbacher John P JP Bowie Rauri C K RCK Henderson James B JB Wall Jeffrey D JD

G3 (Bethesda, Md.) 20181210 12

As the barred owl (Strix varia; Aves: Strigiformes: Strigidae) expands throughout western North America, hybridization between barred and spotted owls (Strix varia and S. occidentalis, respectively), if abundant, may lead to genetic swamping of the endangered spotted owl. We analyzed low-coverage, whole-genome sequence data from fifty-one barred and spotted owls to investigate recent introgression between these two species. Although we obtained genomic confirmation that thes ...[more]

PMID: 30355766

Similar Datasets

Project description:State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia)-a significant threat to northern spotted owls-can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris) located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service's Draft 2010 Survey Protocol. Seventeen 2 km × 2 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the Northern Spotted Owl.

Project description:Genetic differentiation among Spotted Owl (Strix occidentalis) subspecies has been established in prior studies. These investigations also provided evidence for introgression and hybridization among taxa but were limited by a lack of samples from geographic regions where subspecies came into close contact. We analyzed new sets of samples from Northern Spotted Owls (NSO: S. o. caurina) and California Spotted Owls (CSO: S. o. occidentalis) in northern California using mitochondrial DNA sequences (mtDNA) and 10 nuclear microsatellite loci to obtain a clearer depiction of genetic differentiation and hybridization in the region. Our analyses revealed that a NSO population close to the northern edge of the CSO range in northern California (the NSO Contact Zone population) is highly differentiated relative to other NSO populations throughout the remainder of their range. Phylogenetic analyses identified a unique lineage of mtDNA in the NSO Contact Zone, and Bayesian clustering analyses of the microsatellite data identified the Contact Zone as a third distinct population that is differentiated from CSO and NSO found in the remainder of the subspecies' range. Hybridization between NSO and CSO was readily detected in the NSO Contact Zone, with over 50% of individuals showing evidence of hybrid ancestry. Hybridization was also identified among 14% of CSO samples, which were dispersed across the subspecies' range in the Sierra Nevada Mountains. The asymmetry of hybridization suggested that the hybrid zone may be dynamic and moving. Although evidence of hybridization existed, we identified no F1 generation hybrid individuals. We instead found evidence for F2 or backcrossed individuals among our samples. The absence of F1 hybrids may indicate that (1) our 10 microsatellites were unable to distinguish hybrid types, (2) primary interactions between subspecies are occurring elsewhere on the landscape, or (3) dispersal between the subspecies' ranges is reduced relative to historical levels, potentially as a consequence of recent regional fires.

Project description:BackgroundOwls have been reported as definitive hosts, whereas wild small mammals (naturally and experimentally) as intermediate hosts of several species of Sarcocystis. Recently, dead fledglings were found infected by an unnamed species of Sarcocystis since its intermediate host was unknown. After collecting additional samples of owls and wild small mammals, the present study focused on elucidating the identity, potential intermediate host, and complete life cycle of the found Sarcocystis through experimentally infected rodents. The developmental stages' morphological and molecular characterizations (28S rRNA gene, ITS1 region) are presented herein.MethodsIn total, 21 Tengmalm's owl carcasses (15 nestlings, 5 fledglings, and 1 adult male) were collected in Kauhava (west-central Finland) and parasitologically examined by wet mounts. Intestinal mucosa scrapings were used to isolate oocysts/sporocysts and employed for experimental infections in dexamethasone-immunosuppressed BALB/cOlaHsd mice. Additionally, sarcocysts were searched in the skeletal muscle of 95 samples from seven wild small mammal species. All these developmental stages were molecularly characterized by the 28S rRNA gene and ITS1 region. Experimental infections were carried out by using immunosuppressed female 8-week-old BALB/cOlaHsd mice, divided into three groups: (1) water with 15 μg/mL of dexamethasone, (2) water with 30 μg/mL of dexamethasone, (3) no dexamethasone treatment. Each group consisted of four individuals. In each group, two mice were infected with 1,000 sporocysts each, and the remaining two with 10,000 sporocysts each. All mice were euthanized on specific days post-infection.ResultsThe intestinal mucosa of 11 nestlings and 5 fledglings of the Tengmalm's owl were positive for Sarcocystis funereus sp. nov. The adult male owl and all owls' breast and heart muscles were negative for Sarcocystis. Two dexamethasone-immunosuppressed BALB/cOlaHsd mice (group 2) were positive to S. funereus sp. nov. in diaphragm and leg muscles after 22- and 24-day post-infection. Some sarcocysts were found in the wild small mammals. Molecular identification at 28S rRNA revealed sequences from naturally infected Tengmalm's owls, as well as sarcocysts of dexamethasone-immunosuppressed BALB/cOlaHsd mice were 99.87-100% similar to Sarcocystis sp. isolate Af1 previously found in the Tengmalm's owl. At the ITS1 region, the S. funereus sp. nov. isolates Af2 haplotype B and Af3 haplotype A were 98.77-100% identical to Sarcocystis sp. isolate Af1. The sequences from sarcocysts of naturally infected wild small mammals were 75.23-90.30% similar at ITS1 region to those of S. funereus sp. nov.ConclusionThe morphological and molecular characterizations and phylogenetic placement of S. funereus sp. nov. are presented here for the first time and support the erection of the new species.

Dataset Information

Whole-Genome Analysis of Introgression Between the Spotted Owl and Barred Owl (Strix occidentalis and Strix varia, Respectively; Aves: Strigidae) in Western North America.

Publications

Whole-Genome Analysis of Introgression Between the Spotted Owl and Barred Owl (<i>Strix occidentalis</i> and <i>Strix varia</i>, Respectively; Aves: Strigidae) in Western North America.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets