Presentation Title

Genome-wide Differentiation between Hybridizing Hummingbird Lineages

Faculty Mentor

Alan Brelsford

Start Date

18-11-2017 12:30 PM

End Date

18-11-2017 1:30 PM

Location

BSC-Ursa Minor 49

Session

Poster 2

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

Hybrid zones provide a region in which gene flow can be analyzed by evaluating genetic differences between hybrids and their hybridizing lineages. Gene flow analyses of hybrid species allow for the process of speciation to be observed at the genetic level. Prior to examining gene flow in the hybrid zone, the genetic differences outside of the hybrid zone must be established. In this study, the hybridizing species, Allen’s hummingbirds (Selasphorus sasin), found in Northern California, and Rufous hummingbirds (Selasphorus rufus), found in Southern Oregon, were analyzed for genetic variability and differentiation. The individual genomes (nine Allen’s hummingbird genomes and seven Rufous hummingbird genomes) were sequenced using Illumina HiSeq, aligned to a recently assembled Anna’s hummingbird (Calypte anna) genome and analyzed to determine genetic variability between the two species. Single nucleotide polymorphisms (SNPs) were identified and filtered to determine the nucleotide diversity (π) within species as well as differentiation (FST) between the species. Nucleotide diversity was low and consistent, having an average π value of 0.00028 and 0.00032 for the Allen’s and Rufous genomes respectively. Differentiation was relatively low overall (FST = 0.051), but 134 scaffolds containing regions of high differentiation were identified (FST > 0.5), with highly differentiated regions amounting to 0.67% of the genome. Of a total of 1.6 million SNPs, only 81 species-diagnostic SNPs were identified, of which 82% were on the Z chromosome. These results suggest the sex chromosome plays an important role in reproductive isolation between the two species.

Summary of research results to be presented

I analyzed 16 hummingbird genomes between two species - Allen's and Rufous hummingbirds. Since these two species hybridize, it is important to establish the genetic differences that exist between them before studying the corresponding hybrid species. I conducted genome-wide analyses to determine the genomic differences between the two species. I have found that the sex chromosome (Z chromosome), contained the majority (82%) of the single nucleotide polymorphisms between the two species. This confirms what is known about other bird species, that evolution is male driven.

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Nov 18th, 12:30 PM Nov 18th, 1:30 PM

Genome-wide Differentiation between Hybridizing Hummingbird Lineages

BSC-Ursa Minor 49

Hybrid zones provide a region in which gene flow can be analyzed by evaluating genetic differences between hybrids and their hybridizing lineages. Gene flow analyses of hybrid species allow for the process of speciation to be observed at the genetic level. Prior to examining gene flow in the hybrid zone, the genetic differences outside of the hybrid zone must be established. In this study, the hybridizing species, Allen’s hummingbirds (Selasphorus sasin), found in Northern California, and Rufous hummingbirds (Selasphorus rufus), found in Southern Oregon, were analyzed for genetic variability and differentiation. The individual genomes (nine Allen’s hummingbird genomes and seven Rufous hummingbird genomes) were sequenced using Illumina HiSeq, aligned to a recently assembled Anna’s hummingbird (Calypte anna) genome and analyzed to determine genetic variability between the two species. Single nucleotide polymorphisms (SNPs) were identified and filtered to determine the nucleotide diversity (π) within species as well as differentiation (FST) between the species. Nucleotide diversity was low and consistent, having an average π value of 0.00028 and 0.00032 for the Allen’s and Rufous genomes respectively. Differentiation was relatively low overall (FST = 0.051), but 134 scaffolds containing regions of high differentiation were identified (FST > 0.5), with highly differentiated regions amounting to 0.67% of the genome. Of a total of 1.6 million SNPs, only 81 species-diagnostic SNPs were identified, of which 82% were on the Z chromosome. These results suggest the sex chromosome plays an important role in reproductive isolation between the two species.