Allan Wilson Center

Auckland, New Zealand

Allan Wilson Center

Auckland, New Zealand
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Steinwender B.,New Zealand Institute for Plant and Food Research | Steinwender B.,University of Auckland | Steinwender B.,Allan Wilson Center | Thrimawithana A.H.,New Zealand Institute for Plant and Food Research | And 4 more authors.
Journal of Molecular Evolution | Year: 2014

How new mate recognition systems evolve when changes are required in both the male and female components remains a conundrum. Here, we investigated the molecular basis of pheromone reception in two species of tortricid (leafroller) moth, Ctenopseustis obliquana and C. herana. Male C. obliquana are attracted to a 90:10 blend of (Z)-8-tetradecenyl acetate (Z8-14:OAc) and (Z)-5-tetradecenyl acetate (Z5-14:OAc), whereas C. herana males are attracted to Z5-14:OAc alone. We used a transcriptome sequencing approach from adult male and female antennae to identify 47 olfactory receptors (ORs) from each species and assessed their expression levels in male and female antennae using RNA-Seq counting and quantitative RT-PCR. Three male-biased and one female-biased OR were identified in C. obliquana by quantitative RT-PCR, and four male-biased and one female-biased receptor in C. herana. The male-biased receptors, CoblOR7, CoblOR30, CherOR7, CherOR30, CherOR1a and CherOR1b were tested for their ability to respond to sex pheromone components in a HEK293 cell calcium assay. CoblOR7 and CherOR7 responded to Z8-14:OAc, however, no receptor for Z5-14:OAc was identified. In addition to Z8-14:OAc, CherOR7 also responded to Z7-14:OAc, indicating that this receptor may be under relaxed constraint. Of the 29 amino acid differences between CoblOR7 and CherOR7, significantly more are located in the third and the sixth transmembrane domain regions. Overall, these findings are consistent with studies revealing the presence of neurons tuned to both Z8-14:OAc and Z5-14:OAc in both species, but that for C. herana males, the ability to detect Z8-14:OAc is currently not required. © 2014, Springer Science+Business Media New York.

Buckley T.R.,Landcare Research | Buckley T.R.,University of Auckland | Buckley T.R.,Allan Wilson Center | Myers S.S.,Landcare Research | And 3 more authors.
Zootaxa | Year: 2014

We describe two new species of Clitarchus Stål from Northland, New Zealand. Clitarchus rakauwhakanekeneke sp. nov. is described from the Poor Knights Islands and Clitarchus tepaki sp. nov. is described from the Te Paki/North Cape area and the Karikari Peninsula at the northernmost tip of New Zealand. Two new synonymies are proposed including Clitarchus multidentatus Brunner (syn. nov.) and Clitarchus tuberculatus Salmon (syn. nov.) as synonyms of Clitarchus hookeri (White). Clitarchus magnus Brunner, recorded from Thailand, is transferred to Ramulus Saussure and given the replacement name Ramulus changmaiense nom. nov. The holotype of C. multidentatus was recorded as being collected from New Caledonia; however we believe this is a labelling error and the specimen was collected from New Zealand. These taxonomic changes render Clitarchus endemic to New Zealand and consisting of three species; C. hookeri, C. rakauwhakanekeneke and C. tepaki. Keys to the adult males and females of Clitarchus species are given in addition to notes on host plants, ecology and geographic distributions. Copyright © 2014 Magnolia Press.

Bennik R.M.,University of Auckland | Buckley T.R.,University of Auckland | Buckley T.R.,Landcare Research | Buckley T.R.,Allan Wilson Center | And 2 more authors.
Systematic Entomology | Year: 2016

Male genitalia are among the most rapidly evolving and divergent morphological structures and sexual selection is known to drive this phenomenon in many taxa. Because of their diversity, even within a single genus, genital characters are frequently used to infer relationships among closely-related species. Moths within the genus Izatha (Xyloryctidae) are ideal candidates for investigating the phylogenetic patterns of genital evolution as they display great variation in male genital structure and complexity. We determined the evolutionary relationships among 31 species of Izatha by constructing a molecular phylogeny of the genus based on the mitochondrial cytochrome oxidase subunit I gene and the isocitrate dehydrogenase and carbamoylphosphate synthase domain protein nuclear genes. This allowed estimations of ancestral male genital character states and patterns of male genital diversification using maximum-likelihood models. The genus is divided into two well-supported clades and two poorly supported clades at the root of the phylogeny with incomplete phylogenetic resolution within two species groups, likely due to rapid speciation. Izatha display a number of apomorphic phallic traits including cornuti (sclerotized spines) which are either discharged into the female during copulation (deciduous cornuti) or fixed to the male phallus (compound and fish-hook cornuti). Within the genus, there is a reduction of secondary genital characters - the uncus and gnathos - but an elaboration of another grasping structure, the juxta; the potential origin and functionality of these male genital traits are discussed. Overall, some male genital characters provided a good indication of species relationships; however, several parts of the complex male genitalia of Izatha show evidence of homoplasy and convergence highlighting the problems of using these traits in determining species relationships. Additionally, this convergence has highlighted that complex genital structures may evolve repeatedly and independently within a lineage. © 2016 The Royal Entomological Society.

Myers S.S.,Landcare Research | Myers S.S.,University of Auckland | Myers S.S.,Allan Wilson Center | Buckley T.R.,Landcare Research | And 3 more authors.
Behaviour | Year: 2015

For animals that exhibit a scramble competition mating system, sexual selection pressures on mate searching ability are expected to be strong. Scramble competition mating systems evolve when populations provide females with equal accessibility to all male competitors, yet sex ratio and population density influences mating systems and varies seasonally. The stick insect species, Clitarchus hookeri, is frequently found in copula, yet very little is known about it's mating behaviour. We preformed behavioural tests and assayed antennal sensory morphology to determine whether males used chemosensory cues to detect females. Through natural field observations we found populations to be significantly male-biased earlier in the season, while later, populations began to display equal sex ratios.With increasing female availability mating pair proportions steadily increased, while copulation duration declined. These results support C. hookeri as a scramble competitor, and demonstrate males may alter their behaviour in response to the seasonal variation in female density. © 2015 Koninklijke Brill NV, Leiden.

Bradler S.,University of Gottingen | Cliquennois N.,P.A. College | Buckley T.R.,Landcare Research | Buckley T.R.,University of Auckland | Buckley T.R.,Allan Wilson Center
BMC Evolutionary Biology | Year: 2015

Background: The study of islands as model systems plays a key role in understanding many evolutionary processes. Knowledge of the historical events leading to present-day island communities is pivotal for exploring fundamental mechanisms of speciation and adaptation. The remote Mascarene archipelago (Mauritius, Réunion, Rodrigues), considered to be the product of an age-progressive trend of north-to-south volcanic activity in the Indian Ocean, hosts a remarkably diverse, endemic and threatened concentration of flora and fauna that has traditionally been considered to be biogeographically related to Madagascar and Africa. To explore the evolutionary diversity of the Mascarene stick insects (Phasmatodea), we constructed a global phylogeny from approximately 2.4 kb of mitochondrial and nuclear sequence data of more than 120 species representing all major phasmatodean lineages. Results: Based on the obtained time-calibrated molecular tree we demonstrate that the current phasmid community of the Mascarene archipelago, which consists of members of four presumably unrelated traditional subfamilies, is the result of a single ancient dispersal event from Australasia and started radiating between 16-29 million years ago, significantly predating the age of Mauritius (8-10 million years). Conclusions: We propose that the Mascarene stick insects diversified on landmasses now eroded away, presumably to the north of Mauritius. In consequence, ancient islands have probably persisted in the Indian Ocean until the emergence of Mauritius and not only served as stepping stones for colonisation events during sea-level lowstands, but as long-lasting cradles of evolution. These ancient landmasses most likely allowed for adaptive speciation and served as significant sources of diversity that contributed to the biomes of the Mascarene archipelago and the megadiverse Madagascar. © 2015 Bradler et al.

Buckley T.R.,Landcare Research | Buckley T.R.,University of Auckland | Buckley T.R.,Allan Wilson Center | Krosch M.,University of Queensland | Leschen R.A.B.,Landcare Research
Austral Entomology | Year: 2015

Knowledge on the evolution of the New Zealand insect fauna is reviewed and outstanding questions are highlighted. The New Zealand insect fauna is a composite of old and recent lineages and many spectacular examples of evolutionary processes are evident, including species radiations, hybridisation and unusual adaptations. We discuss the origins and evolution of four prominent communities within the insect fauna: terrestrial lowland insects, alpine insects, aquatic insects and insect communities from offshore islands. Within each of these communities, significant lineages are discussed, and in particular the crucial adaptations that enable these lineages to thrive and diversify. Glacial history has had a dramatic impact on the New Zealand insects, and the effects on different lineages are discussed. The New Zealand insects are unique, yet many are threatened with extinction, and efforts to preserve the fauna are reviewed. Despite the accumulating knowledge, major gaps still exist and these are outlined, as are opportunities to address key questions. The review concludes with a synthesis and a discussion of how systematics, new technologies and integrative approaches have the promise to improve dramatically our understanding of New Zealand insect evolution. © 2014 Australian Entomological Society.

Dussex N.,University of Otago | Dussex N.,Allan Wilson Center | Robertson B.C.,University of Otago | Robertson B.C.,University of Canterbury | And 6 more authors.
Journal of Heredity | Year: 2016

Population declines resulting from anthropogenic activities are of major consequence for the long-term survival of species because the resulting loss of genetic diversity can lead to extinction via the effects of inbreeding depression, fixation of deleterious mutations, and loss of adaptive potential. Otariid pinnipeds have been exploited commercially to near extinction with some species showing higher demographic resilience and recolonization potential than others. The New Zealand fur seal (NZFS) was heavily impacted by commercial sealing between the late 18th and early 19th centuries, but has recolonized its former range in southern Australia. The species has also recolonized its former range in New Zealand, yet little is known about the pattern of recolonization. Here, we first used 11 microsatellite markers (n = 383) to investigate the contemporary population structure and dispersal patterns in the NZFS (Arctocephalus forsteri). Secondly, we model postsealing recolonization with 1 additional mtDNA cytochrome b (n = 261) marker. Our data identified 3 genetic clusters: an Australian, a subantarctic, and a New Zealand one, with a weak and probably transient subdivision within the latter cluster. Demographic history scenarios supported a recolonization of the New Zealand coastline from remote west coast colonies, which is consistent with contemporary gene flow and with the species' high resilience. The present data suggest the management of distinct genetic units in the North and South of New Zealand along a genetic gradient. Assignment of individuals to their colony of origin was limited (32%) with the present data indicating the current microsatellite markers are unlikely sufficient to assign fisheries bycatch of NZFSs to colonies. © 2016 The American Genetic Association 2016.

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