TY - JOUR
T1 - Phylogenomic analysis of seal lice reveals codivergence with their hosts
AU - Leonardi, María Soledad
AU - Virrueta Herrera, Stephany
AU - Sweet, Andrew
AU - Negrete, Javier
AU - Johnson, Kevin P.
N1 - Funding Information:
We thank Rebecca McIntosh and Christine Fontaine for lice samples from Australian sea lions and northern fur seals, respectively. The study was financially and logistically supported by the Direcci?n Nacional del Ant?rtico, Instituto Ant?rtico Argentino PICTO 2010-01. The permit for this work was granted by the Direcci?n Nacional del Ant?rtico (Departamento de Gesti?n Ambiental y Turismo). Samples of Antarctophthirus microchir [CNP-PAR 82] were collected by MSL with funds from Marine Mammals Lab (CENPAT). This research was funded by the Agencia de Promoci?n Cient?fica y Tecnol?gica (PICT 2015-0082) and Lerner-Grey Fund for Marine Research to MSL and US NSF DEB-1239788, DEB-1342604, and DEB-160002 to KPJ. The authors express their support to the Argentinian scientific programme, and thank the public policies during the period 2003?2015 that made possible this research. MSL on behalf of all co-authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers' bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), and no financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Lice are considered a model system for studying the process of cospeciation because they are obligate and permanent parasites and are often highly host-specific. Among lice, species in the family Echinophthiriidae Enderlein (Anoplura) are unique in that they infest mammalian hosts with an amphibious lifestyle, i.e. pinnipeds and the river otter. There is evidence that the ancestor of this group infested the terrestrial ancestor of pinnipeds, which suggests these parasites coevolved with their hosts during the transition to marine environments. However, there has been no previous study investigating the phylogenetic relationships among sucking lice parasitizing seals and sea lions. To uncover the evolutionary history of these parasites, we obtained genomic data for Antarctophthirus microchir Trouessart and Neumann (from two hosts), Antarctophthirus carlinii Leonardi et al., Antarctophthirus lobodontis Enderlein, Antarctophthirus ogmorhini Enderlein, Lepidophthirus macrorhini Enderlein, and Proechinophthirus fluctus Ferris. From genomic sequence reads, we assembled > 1000 nuclear genes and used these data to infer a phylogenetic tree for these lice. We also used the assembled genes in combination with read-mapping to estimate heterozygosity and effective population size from individual lice. Our analysis supports the monophyly of lice from pinnipeds and uncovers phylogenetic relationships within the group. Surprisingly, we found that A. carlinii, A. lobodontis, and A. ogmorhini have very little genetic divergence among them, whereas the divergence between different geographic representatives of A. microchir indicate that they are possibly different species. Nevertheless, our phylogeny of Echinophthiriidae suggests that these lice have consistently codiverged with their hosts with minimal host switching. Population genomic metrics indicate that louse effective population size is linked to host demographics, which further highlights the close association between pinnipeds and their lice.
AB - Lice are considered a model system for studying the process of cospeciation because they are obligate and permanent parasites and are often highly host-specific. Among lice, species in the family Echinophthiriidae Enderlein (Anoplura) are unique in that they infest mammalian hosts with an amphibious lifestyle, i.e. pinnipeds and the river otter. There is evidence that the ancestor of this group infested the terrestrial ancestor of pinnipeds, which suggests these parasites coevolved with their hosts during the transition to marine environments. However, there has been no previous study investigating the phylogenetic relationships among sucking lice parasitizing seals and sea lions. To uncover the evolutionary history of these parasites, we obtained genomic data for Antarctophthirus microchir Trouessart and Neumann (from two hosts), Antarctophthirus carlinii Leonardi et al., Antarctophthirus lobodontis Enderlein, Antarctophthirus ogmorhini Enderlein, Lepidophthirus macrorhini Enderlein, and Proechinophthirus fluctus Ferris. From genomic sequence reads, we assembled > 1000 nuclear genes and used these data to infer a phylogenetic tree for these lice. We also used the assembled genes in combination with read-mapping to estimate heterozygosity and effective population size from individual lice. Our analysis supports the monophyly of lice from pinnipeds and uncovers phylogenetic relationships within the group. Surprisingly, we found that A. carlinii, A. lobodontis, and A. ogmorhini have very little genetic divergence among them, whereas the divergence between different geographic representatives of A. microchir indicate that they are possibly different species. Nevertheless, our phylogeny of Echinophthiriidae suggests that these lice have consistently codiverged with their hosts with minimal host switching. Population genomic metrics indicate that louse effective population size is linked to host demographics, which further highlights the close association between pinnipeds and their lice.
KW - INHS
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U2 - 10.1111/syen.12350
DO - 10.1111/syen.12350
M3 - Article
AN - SCOPUS:85062537265
SN - 0307-6970
VL - 44
SP - 699
EP - 708
JO - Systematic Entomology
JF - Systematic Entomology
IS - 4
ER -