Impact of hybridisation in two Cossypha robin-chat species in southern Africa
Author and article information
Abstract
Chorister Robin-Chat Cossypha dichroa, a South African forest endemic, and Red-capped Robin-Chat C. natalensis, a widely distributed species in African forest and woodland, are inferred to hybridise in areas of sympatry. DNA was extracted from blood samples of C. dichroa (n = 18), C. natalensis (n = 47), and two phenotypic hybrids. The mitochondrial cytochrome c oxidase I (COI) gene was amplified by PCR and sequenced. Phylogenetic analysis was performed on the sequence data to investigate taxonomic status and putative interspecific hybridisation. Phenotypic hybrids grouped with C. natalensis, suggesting maternal parentage from that species. Intra- and interspecific genetic and geographic distances were compared between C. dichroa and C. natalensis to assess genetic introgression. Seven of the thirteen microsatellite primer pairs developed for C. natalensis cross amplified in C. dichroa. These seven markers were then used for further analysis. STRUCTURE v2.3.4 was used to assign individuals to a particular genetic cluster and determine any admixture. NEWHYBRIDS v1.1 was used to assign hybrid status to samples beyond the F1 generation. Despite the hybridisation events recorded between C. dichroa and C. natalensis they still form two separate clusters as expected, and two genetic clusters (K=2) were identified using STRUCTURE. These two species are proficient vocal mimics and it is likely that reproductive isolation mechanisms are overcome through vocalisations. Genotypic hybrids are evident in the sampled population and hybridisation and backcrossing across a zone of sympatry is occurring. However, hybridisation is expected to have very little evolutionary influence on the integrity of recently diverged species which retain reproductive isolation across a wide region of sympatry through call distinctness.
Cite this as
2019. Impact of hybridisation in two Cossypha robin-chat species in southern Africa. PeerJ Preprints 7:e27912v1 https://doi.org/10.7287/peerj.preprints.27912v1Author comment
This is a submission to PeerJ for review.
Sections
Supplemental Information
Fieldwork and bird ringing data
Appendix 1: Bird ringing data including field sites, measurements and sexing.
Genotyping data for analysis using STRUCTURE and NEWHYBRIDS
Appendix 2: Microsatliite data for anaylsis using STRUCTURE and NEWHYBRIDS
Jeffreys Q values
Appendix 3: Jeffreys prior Q values
COI sequences for Cossypha natalensis
Sequences uploaded to GenBank which have accession numbers but are not available yet.
COI mitochondrial sequences for Cossypha dichroa
Sequences uploaded to GenBank which have accession numbers but are not available yet.
Uniform Q vaues
Appendix 4: Uniform prior Q vaues
Additional Information
Competing Interests
The authors declare that they have no competeing interests.
Author Contributions
Jean Mollett conceived and designed the experiments, analyzed the data, contributed reagents/materials/analysis tools, authored or reviewed drafts of the paper, approved the final draft.
Naadhirah Munshi performed the experiments, analyzed the data, prepared figures and/or tables.
Craig Symes conceived and designed the experiments, authored or reviewed drafts of the paper, approved the final draft, prof Symes is an ornithologist and registered Bird Ringer. He did all the fieldwork and collected the blood samples.
Animal Ethics
The following information was supplied relating to ethical approvals (i.e., approving body and any reference numbers):
Bird capture was conducted under permit from Ezemvelo KZN Wildlife (OP1785/2010), Limpopo Province (001-CPM401-00005/2012-2013) and ethics clearance from the University of the Witwatersrand, Animal Ethics Screening Committee: blood and feather collection (2009.42/2A).
Field Study Permissions
The following information was supplied relating to field study approvals (i.e., approving body and any reference numbers):
Fieldwork was conducted under permit from Ezemvelo KZN Wildlife (OP1785/2010), Limpopo Province (001-CPM401-00005/2012-2013)
DNA Deposition
The following information was supplied regarding the deposition of DNA sequences:
Sequences generated by this study were deposited on GenBank: accession numbers for Cossypha dichroa samples MK475629-MK475646 and Cossypha natalensis samples MK475579-MK475626 and for the two inferred hybrids MK475627-MK475628.
Data Deposition
The following information was supplied regarding data availability:
The raw data provided in supplementary files 1 to 4 include (1) the bird ringing information, (2) the Microsatellite data , (3 and 4) the data for Jeffreys and Uniform Priors after the NEWHYBRID analyses.
Funding
The authors received no external funding for this work. It was internally funded by start-up Faculty funding.
