Repeated sequences, especially transposable elements (TEs), are known to be abundant in some members of the important invertebrate class Gastropoda. TEs that do not have long terminal repeated sequences (non-LTR TEs) are frequently the most abundant type but have not been well characterised in any gastropod. Despite this, sequences in draft gastropod genomes are often described as non-LTR TEs, but without identification to family type.
View Article and Find Full Text PDFMany species of the gastropod genus have been named from northeastern Asia but scanty descriptions based predominantly on shells make it difficult to determine which are valid. This, plus the sporadic anatomical and genetic information available for many of these species has led to what may be described as an un-integrated taxonomy. In this situation, it is generally preferable to postpone dissection of rare and unusual specimens until relevant diagnostic characters can be established in broader studies.
View Article and Find Full Text PDFBackground: The koala, Phascolarctos cinereus, is a biologically unique and evolutionarily distinct Australian arboreal marsupial. The goal of this study was to sequence the transcriptome from several tissues of two geographically separate koalas, and to create the first comprehensive catalog of annotated transcripts for this species, enabling detailed analysis of the unique attributes of this threatened native marsupial, including infection by the koala retrovirus.
Results: RNA-Seq data was generated from a range of tissues from one male and one female koala and assembled de novo into transcripts using Velvet-Oases.
Simulium is a very speciose genus of the black fly family Simuliidae that includes many important pests of humans and animals. Cytotaxonomic and morphological studies have made substantial progress in Simulium systematics. 16S rRNA and ITS-1 DNA sequence studies have assisted this progress.
View Article and Find Full Text PDFA species flock of the freshwater isopod genus Eophreatoicus Nicholls lives in seeps, springs and perched aquifers at the base of the Arnhem Plateau and associated sandstone outliers in Australia's Northern Territory. These species have been found to have surprisingly high levels of genetic divergence and narrow range endemism, despite potential opportunities for dispersion during the summer monsoon season when streams flow continuously and have connectivity. Species of Eophreatoicus were identified morphologically as distinct taxa, sometimes with two or three species occurring at the same site.
View Article and Find Full Text PDFThe true crabs, the Brachyura, are generally divided into two major groups: Eubrachyura or 'advanced' crabs, and Podotremata or 'primitive' crabs. The status of Podotremata is one of the most controversial issues in brachyuran systematics. The podotreme crabs, best recognised by the possession of gonopores on the coxae of the pereopods, have variously been regarded as mono-, para- or polyphyletic, or even as non-brachyuran.
View Article and Find Full Text PDFThe Great Artesian Basin (GAB) of Australia underlies some of the driest parts of South Australia and Queensland and feeds numerous freshwater springs. Prominent and endangered components of the GAB spring community are snails of the family Hydrobiidae. This paper examines the evolutionary relationships of the entire hydrobiid fauna associated with the GAB, and includes appropriate non-GAB species to place the GAB fauna in a broader phylogenetic context.
View Article and Find Full Text PDFExtant mammals are composed of three lineages: the eutherians, the marsupials and the monotremes. The majority of the mammalian major histocompatibility complex (MHC) data is based on the eutherian mammals, which generally have three classical MHC class II beta chain gene clusters - DRB, DQB and DPB, as well as the non-classical DMB and DOB. Marsupial DMB, DAB and DBB have been characterised.
View Article and Find Full Text PDFMorphological, developmental, ultrastructural, and gene order characters are catalogued for the same set of arthropod terminals as we have scored in a recent study of histone H3 and U2 snRNA sequences (D. J. Colgan et al.
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