ORCID Profile
0000-0002-6190-6426
Current Organisations
The University of Canberra
,
Laboratório Nacional de Computação Científica
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Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-1995
DOI: 10.1109/78.370625
Publisher: Elsevier BV
Date: 2010
Publisher: Wiley
Date: 24-10-2023
DOI: 10.1111/MEC.17174
Publisher: Wiley
Date: 08-1992
Publisher: Elsevier BV
Date: 12-2009
Publisher: Oxford University Press (OUP)
Date: 05-03-2018
DOI: 10.1093/GBE/EVY042
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-1993
DOI: 10.1109/9.210145
Publisher: CSIRO Publishing
Date: 28-09-2020
DOI: 10.1071/ZO21017
Abstract: Australian lizards are a erse group distributed across the continent and inhabiting a wide range of environments. Together, they exhibit a remarkable ersity of reproductive morphologies, physiologies, and behaviours that is broadly representative of vertebrates in general. Many reproductive traits exhibited by Australian lizards have evolved independently in multiple lizard lineages, including sociality, complex signalling and mating systems, viviparity, and temperature-dependent sex determination. Australian lizards are thus outstanding model organisms for testing hypotheses about how reproductive traits function and evolve, and they provide an important basis of comparison with other animals that exhibit similar traits. We review how research on Australian lizard reproduction has contributed to answering broader evolutionary and ecological questions that apply to animals in general. We focus on reproductive traits, processes, and strategies that are important areas of current research, including behaviours and signalling involved in courtship mechanisms involved in mating, egg production, and sperm competition nesting and gestation sex determination and finally, birth in viviparous species. We use our review to identify important questions that emerge from an understanding of this body of research when considered holistically. Finally, we identify additional research questions within each topic that Australian lizards are well suited for reproductive biologists to address.
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/MF14423
Abstract: The lack of independently verifiable estimates of catches and fisheries independent estimates of abundance and fishing mortality are major sources of uncertainty in the management of many fisheries. DNA profiling provides the potential to substantially improve the quality of data for assessments and act as an additional deterrent to illegal, unreported, and unregulated (IUU) fishing. Barriers to the implementation of this technology include cost of s le collection and processing, forensic grade quality control, and the ability to apply undetectable tags. We present the results of a comparison of two current and one new (gene tag tool, GTT) s ling techniques, using the highly valued southern bluefin tuna as an ex le. We demonstrate that fish s led with two techniques are highly unlikely to be recognised as ‘tagged’, whereas one technique was easily recognisable after 73 days. The GTT reduced handling before DNA extraction, whereas both other techniques require additional labour, adding to cost and potential contamination of the evidentiary chain. Evidence of cross-contamination in the Whatman FTA Elute s les suggests they may not be as suitable for at-sea field applications. Two of the three s ling techniques are capable of obtaining high quality tissue s les for stock assessment and chain of custody purposes in a cost-effective and unidentifiable manner.
Publisher: Cold Spring Harbor Laboratory
Date: 31-01-2018
DOI: 10.1101/257428
Abstract: Sex determination systems are exceptionally erse and have undergone multiple and independent evolutionary transitions among species, particularly reptiles. However, the mechanisms underlying these transitions have not been established. Here we tested for differences in sex-linked markers in the only known reptile that is polymorphic for sex determination system, the spotted snow skink, Niveoscincus ocellatus, to quantify the genomic differences that have accompanied this transition. In a highland population, sex is determined genetically, whilst in a lowland population, offspring sex ratio is influenced by temperature. We found a similar number of sex-linked loci in each population, including shared loci, with genotypes consistent with male heterogamety (XY). However, population-specific linkage disequilibrium suggests greater ergence of sex chromosomes in the highland population. Our results suggest that transitions between sex determination systems (GSD and TSD-like systems) can be facilitated by subtle genetic differences.
Publisher: MDPI AG
Date: 02-2021
Abstract: Sex determination directs development as male or female in sexually reproducing organisms. Evolutionary transitions in sex determination have occurred frequently, suggesting simple mechanisms behind the transitions, yet their detail remains elusive. Here we explore the links between mechanisms of transitions in sex determination and sex chromosome evolution at both recent and deeper temporal scales ( Myr ~79 Myr). We studied a rare ex le of a species with intraspecific variation in sex determination, Carinascincus ocellatus, and a relative, Liopholis whitii, using c-banding and mapping of repeat motifs and a custom Y chromosome probe set to identify the sex chromosomes. We identified both unique and conserved regions of the Y chromosome among C. ocellatus populations differing in sex determination. There was no evidence for homology of sex chromosomes between C. ocellatus and L. whitii, suggesting independent evolutionary origins. We discuss sex chromosome homology between members of the subfamily Lygosominae and propose links between sex chromosome evolution, sex determination transitions, and karyotype evolution.
Publisher: Springer Science and Business Media LLC
Date: 23-11-2015
DOI: 10.1038/SREP16916
Abstract: Tropical tuna fisheries are central to food security and economic development of many regions of the world. Contemporary population assessment and management generally assume these fisheries exploit a single mixed spawning population, within ocean basins. To date population genetics has lacked the required power to conclusively test this assumption. Here we demonstrate heterogeneous population structure among yellowfin tuna s led at three locations across the Pacific Ocean (western, central and eastern) via analysis of double digest restriction-site associated DNA using Next Generation Sequencing technology. The differences among locations are such that in iduals s led from one of the three regions examined can be assigned with close to 100% accuracy demonstrating the power of this approach for providing practical markers for fishery independent verification of catch provenance in a way not achieved by previous techniques. Given these results, an extended pan-tropical survey of yellowfin tuna using this approach will not only help combat the largest threat to sustainable fisheries (i.e. illegal, unreported and unregulated fishing) but will also provide a basis to transform current monitoring, assessment and management approaches for this globally significant species.
Publisher: Wiley
Date: 04-1991
Publisher: The Royal Society
Date: 06-2022
Abstract: Evolutionary transitions in sex-determining systems have occurred frequently yet understanding how they occur remains a major challenge. In reptiles, transitions from genetic to temperature-dependent sex determination can occur if the gene products that determine sex evolve thermal sensitivity, resulting in sex-reversed in iduals. However, evidence of sex reversal is limited to oviparous reptiles. Here we used thermal experiments to test whether sex reversal is responsible for differences in sex determination in a viviparous reptile, Carinascincus ocellatus, a species with XY sex chromosomes and population-specific sex ratio response to temperature. We show that sex reversal is occurring and that its frequency is related to temperature. Sex reversal was unidirectional (phenotypic males with XX genotype) and observed in both high- and low-elevation populations. We propose that XX-biased genotypic sex ratios could produce either male- or female-biased phenotypic sex ratios as observed in low-elevation C. ocellatus under variable rates of XX sex reversal. We discuss reasons why sex reversal may not influence sex ratios at high elevation. Our results suggest that the mechanism responsible for evolutionary transitions from genotypic to temperature-dependent sex determination is more complex than can be explained by a single process such as sex reversal.
Publisher: Elsevier BV
Date: 03-2008
Publisher: IEEE
Date: 2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2010
Publisher: Wiley
Date: 25-03-2021
DOI: 10.1002/ECE3.7458
Abstract: Polymorphisms can lead to genetic isolation if there is differential mating success among conspecifics ergent for a trait. Polymorphism for sex‐determining system may fall into this category, given strong selection for the production of viable males and females and the low success of heterogametic hybrids when sex chromosomes differ (Haldane's rule). Here we investigated whether populations exhibiting polymorphism for sex determination are genetically isolated, using the viviparous snow skink Carinascincus ocellatus . While a comparatively high elevation population has genotypic sex determination, in a lower elevation population there is an additional temperature component to sex determination. Based on 11,107 SNP markers, these populations appear genetically isolated. “Isolation with Migration” analysis also suggests these populations erged in the absence of gene flow, across a period encompassing multiple Pleistocene glaciations and likely greater geographic proximity of populations. However, further experiments are required to establish whether genetic isolation may be a cause or consequence of differences in sex determination. Given the influence of temperature on sex in one lineage, we also discuss the implications for the persistence of this polymorphism under climate change.
Start Date: 2017
End Date: 2020
Funder: Australia and Pacific Science Foundation
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