Biomedical subjects

Jane M Hughes

Publications and source records attributed to Jane M Hughes.

10 recordsLinked to original sources

PubMed2006

An island in the stream: Australia's place in the cosmopolitan world of Indo-West Pacific freshwater shrimp (Decapoda: Atyidae: Caridina).

Mitochondrial DNA sequences were used to investigate phylogenetic and biogeographic relationships among Australian freshwater shrimp from the genus Caridina H. Milne Edwards, 1837 (Atyidae) and congeners from potential source populations throughout the Indo-West Pacific region. Numerous Australian taxa have close evolutionary relationships with non-Australian taxa from locations throughout the region, indicating a diverse origin of the Australian freshwater fauna. This implies many colonisations to or from Australia over a long period, and thus highlights the surprising adeptness of freshwater shrimp in dispersal across ocean barriers and the unity of much of the region's freshwater biota. Interestingly, a study on Australia's other main genus of atyid shrimp, Paratya Miers, 1882, inferred only a single colonisation. A number of potential species radiations within Australia were also identified. This agrees with patterns detected for a large number of Australian freshwater taxa, and so implies a vicariant explanation due to the development of colder, dryer climates during the late Miocene/early Pliocene.

Animals↗

PubMed2006

Do ants enhance diversification in lycaenid butterflies? Phylogeographic evidence from a model myrmecophile, Jalmenus evagoras.

The ant-tended Australian butterfly, Jalmenus evagoras, has been a model system for studying the ecology and evolution of mutualism. A phylogeographic analysis of mitochondrial DNA cytochrome oxidase I sequences from 242 butterflies (615 bp) and 66 attendant ants (585 bp) from 22 populations was carried out to explore the relationship between ant association and butterfly population structure. This analysis revealed 12 closely related butterfly haplotypes in three distinct clades roughly corresponding to three allopatric subpopulations of the butterflies. Minimal genetic diversity and widespread haplotypes within biogeographical regions suggest high levels of matrilineal gene flow. Attendant ants are significantly more diverse than was previously thought, with at least seven well-defined clades corresponding to independent morphological determinations, distributed throughout the range of the butterflies. Nested analysis of molecular variance showed that biogeography, host plant, and ant associate all contribute significantly in explaining variation in butterfly genetic diversity, but these variables are not independent of one another. Major influences appear to come from fragmentation due to large-scale biogeographical barriers, and diversification following a shift in habitat preference. A consequence of such a shift could be codiversification of the butterfly with habitat-adapted ants, resulting in apparent phylogenetic concordance between butterflies and ants. The implications of these results are discussed in terms of possible effects of ant attendance on the diversification of Lycaenidae as a whole.

Animals↗

PubMed2005

The taxonomic feedback loop: symbiosis of morphology and molecules.

Here, we relate the ongoing taxonomic story of a species complex of problematic, cryptic Australian freshwater shrimp (Atyidae; Caridina) to highlight the relative strength and utility of different taxonomic methods in assessing species boundaries. We used popular 'DNA barcode' gene fragments cytochrome c oxidase 1 and 16S ribosomal DNA. We then assessed the morphological attributes of these specimens and developed an identification key to complement the molecular results, and conclude that, despite occasionally strident arguments in favour of either molecular or morphological taxonomy, the two are inseparably linked and form parts of a greater whole.

Animals↗

PubMed2004

Mitochondrial DNA phylogenetic structuring suggests similarity between two morphologically plastic genera of Australian freshwater mussels (Unionoida: Hyriidae).

In the Lake Eyre Basin, the Australian hyriid genus Velesunio is represented by three undescribed species, each of which are highly divergent genetically, but morphologically similar to Velesunio wilsonii (Lea 1859). A fourth species, Velesunio ambiguus (Philippi 1847), occurs not only in the Lake Eyre Basin but throughout much of eastern Australia, including the Murray-Darling Basin. In this study, we show that another hyriid, Alathyria jacksoni (Iredale 1934), which is sympatric with V. ambiguus, is genetically deeply nested within the Velesunio species complex, such that the genus Velesunio is paraphyletic with respect to A. jacksoni. Moreover, our mitochondrial phylogenetic reconstructions indicate that A. jacksoni is closely allied to one of the cryptic Velesunio species occurring in the Lake Eyre Basin, but distinct from V. ambiguus and the two other Velesunio species. These data suggest that the genera Alathyria and Velesunio are in need of revision. The shells of A. jacksoni and Velesunio spp. vary with local conditions and sometimes are difficult to distinguish. Our analyses also show that shell characters of these taxa do not closely match the phylogenetic data, and it appears that the traditional taxonomic emphasis on these plastic characters has obscured evolutionary relationships between these, and possibly other, Hyriidae.

Animals↗

PubMed2004

The evolution of Queensland spiny mountain crayfish of the genus Euastacus. I. Testing vicariance and dispersal with interspecific mitochondrial DNA.

The upland mesic rainforests of eastern Australia have been described as a "mesothermal archipelago" where a chain of cool mountain "islands" arise from a warm "sea" of tropical and subtropical lowlands. An endemic freshwater crayfish belonging to the genus Euastacus is found on each of these mountain "islands." The Euastacus are particularly suitable for the study of evolution because each mountain harbors a unique species, there are many taxa present providing replication within the group and, most importantly, their distribution is linear, extending along a south-north axis. This group could have evolved by "simultaneous vicariance" where there was one vicariant separation event of a widespread ancestor, or by "south to north stepping stone dispersal" where there were long distance dispersal events from neighboring mountain islands, starting in the south and proceeding north in a dispersal-colonization wave. We used pairwise genetic distances between nearest geographic neighbors as a novel way to test the two hypotheses. If diversification was due to "south to north stepping stone dispersal," then pairwise genetic distances between nearest geographic neighbors should decrease progressively the farther north the taxon pairs are found, reflecting the decreasing periods of isolation. In this case there should be a negative correlation between the south to north rank order of nearest neighbors and pairwise genetic distances. A Spearman's correlation on 16S mtDNA pairwise genetic distances and geographic rank order was not significant, indicating there was no support for the south to north stepping stone dispersal hypothesis. If simultaneous vicariance was responsible for diversification then all nearest geographic neighbor taxon pairs should have similar genetic distances and, therefore, the variance in nearest neighbor distances should be zero, or close to it. To test if the observed variance was tending towards zero we developed a randomization test where nearest neighbor taxon pairs were assigned random genetic distances and the variances calculated. The observed variance lay in the < 0.05 range of the simulated variances, providing support for the simultaneous vicariance hypothesis. The data also suggest there was simultaneous vicariance of at least two ancestral Queensland lineages. The timing of this vicariant event was probably in the Pliocene, which is consistent with the divergence times reported for other Australian mesic rainforest restricted taxa.

Analysis of Variance↗

PubMed2004

Parents' experiences of caring for their child following day case surgery: a diary study.

The development of children's health care over the last 15-20 years has resulted in an increased move towards ambulatory care, including day case surgery, which has implied benefits in reduced hospitalization and cost. The wider impact on the child and family is less clear. The study aimed for greater insight into the impact of day case surgery on the child and family from the parent's perspective. Using a qualitative approach and descriptive and inductive methods, the design focused on the parent's experiences of their child's surgery. Diaries were completed by 11 families over a 7-14-day period following their child's surgery. Findings demonstrated that there were significant issues for families in managing the care of their child with regard to the social impact for the parent and child, emotional issues for parent and child, and the need for formal and informal support systems.

Adaptation, Psychological↗

PubMed2003

Molecular phylogeny and evolutionary biology of Acrodipsas (Lepidoptera: Lycaenidae).

Most butterflies in the family Lycaenidae associate with ants but fewer than 3% are myrmecophagous. Larvae of the Australian endemic butterfly genus Acrodipsas parasitise the nests of ants from two subfamilies and, thus, constitute an interesting and uncommon myrmecophagous radiation within the Lepidoptera. Phylogenetic relationships among Acrodipsas species were inferred from fragments of mitochondrial cytochrome oxidase subunits I and II totalling 1155 bp using maximum parsimony and a neighbour joining method. Monophyly of the genus was confirmed, as was the sister genus status of Lucia. Acrodipsas myrmecophila was established as the plesiotypic Acrodipsas species, which together with Acrodipsas brisbanensis parasitises the ancestral dolichoderine host-ants. A speciation event associated with a radical host-ant shift to Myrmicinae occurred in an ancestor of Acrodipsas cuprea but subsequent speciation events may have been driven by climatic fluctuations during the Pleistocene. Modifications to leg morphology in several species were found to be a synapomorphic state, which arose subsequent to the host-shift to Myrmicinae. Minimal genetic variation detected in allopatric species exhibiting divergent morphology suggests that phenotypic variability has been driven by strong environmental selective pressures. As a result, morphological differences between closely related allopatric species have evolved faster than genetic differences, most notably between Acrodipsas arcana and Acrodipsas illidgei. In contrast, sympatric lineages of A. brisbanensis across similar habitats show considerable genetic differentiation, yet have remained phenotypically indistinguishable. Successful amplification of short overlapping fragments of DNA from museum specimens confirms their utility for phylogenetic analysis when the availability of fresh tissue is limited.

Animals↗

PubMed2003

Oceanic interchange and nonequilibrium population structure in the estuarine dependent Indo-Pacific tasselfish, Polynemus sheridani.

We assayed mtDNA haplotype [300 base pairs (bp) control region] geography and genealogy in the Indo-Pacific tasselfish, Polynemus sheridani from its contiguous estuarine distribution across northern Australia (n = 169). Eight estuaries were sampled from three oceanographic regions (Timor Sea, Gulf of Carpentaria and the Coral Sea) to assess the impact of Pleistocene sea level changes on the historical connectivity among P. sheridani populations. Specifically, we investigated the genetic consequences of disruption to Indian-Pacific Ocean connectivity brought about by the closure of the Torres Strait. Overall there was significant population subdivision among estuaries (FST = 0.161, PhiST = 0.187). Despite a linear distribution, P. sheridani did not show isolation by distance over the entire sampled range because of genetic similarity of estuaries greater than 3000 km apart. However, significant isolation by distance was detected between estuaries separated by less than 3000 km of coastline. Unlike many genetic studies of Indo-Pacific marine species, there was no evidence for an historical division between eastern and western populations. Instead, phylogeographical patterns were dominated by a starlike intraspecific phylogeny coupled with evidence for population expansion in both the Gulf of Carpentaria and the Coral Sea but not the Timor Sea. This was interpreted as evidence for recent west to east recolonization across of northern Australia following the last postglacial marine advance. We argue that although sufficient time has elapsed postcolonization for populations to approach gene flow-drift equilibrium over smaller spatial scales (< 3000 km), the signal of historical colonization persists to obscure the expected equilibrium pattern of isolation by distance over large spatial scales (> 3000 km).

Animals↗

PubMed2003

Cryptic species and morphological plasticity in long-lived bivalves (Unionoida: Hyriidae) from inland Australia.

Molecular (mitochondrial DNA, isozyme) and morphological diversity of freshwater mussels (Family Hyriidae) was examined at 21 sites encompassing four large river systems, across southwest Queensland, Australia. Evidence was found for two major morphological groups. One group, which occurred in every river system, closely matched a recognized species (Velesunio ambiguus) both morphologically and in a well-supported lineage within a mitochondrial phylogeny generated from partial cytochrome c oxidase subunit I (COI) sequences. The second group most closely matched Velesunio wilsonii in shell morphology but formed three deeply divergent mitochondrial DNA lineages. All four lineages occurred sympatrically in some areas and displayed corresponding fixed differences at nuclear allozyme loci, which suggests an absence of recent hybridization and the presence of separate species.

Animals↗

PubMed2003

A morphological cline in Eucalyptus: a genetic perspective.

The putative hybrid zone between Eucalyptus populnea and E. brownii is examined using morphological and molecular techniques. This species complex displays continuous morphological variation across the study area, which has been previously interpreted as the product of hybridization between allopatric species. A microsatellite analysis indicates that there was little genetic structuring across the morphological cline and only low levels of population differentiation. The nested clade analysis of the JLA+ region of the chloroplast DNA (cpDNA) indicates that the geographical distribution of cpDNA haplotypes is unlikely to be the result of historical hybridization events, and that restricted seed-mediated gene flow with isolation by distance is responsible for the phylogeographical distribution. A more plausible explanation for the origin and persistence of the morphological cline is that the process of continuous morphological diversification has been promoted by a directional selection gradient. This study addresses species status within Eucalyptus and the belief that hybridization is widespread and is an important process in the group's evolution.

Analysis of Variance↗