Project description:Advances in sequencing technologies have revolutionized wildlife conservation genetics. Analysis of genomic data sets can provide high-resolution estimates of genetic structure, genetic diversity, gene flow, and evolutionary history. These data can be used to characterize conservation units and to effectively manage the genetic health of species in a broad evolutionary context. Here we utilize thousands of genome-wide single-nucleotide polymorphisms (SNPs) and mitochondrial DNA to provide the first genetic assessment of the Australian red-tailed black-cockatoo (Calyptorhynchus banksii), a widespread bird species comprising populations of varying conservation concern. We identified five evolutionarily significant units, which are estimated to have diverged during the Pleistocene. These units are only partially congruent with the existing morphology-based subspecies taxonomy. Genetic clusters inferred from mitochondrial DNA differed from those based on SNPs and were less resolved. Our study has a range of conservation and taxonomic implications for this species. In particular, we provide advice on the potential genetic rescue of the Endangered and restricted-range subspecies C. b. graptogyne, and propose that the western C. b. samueli population is diagnosable as a separate subspecies. The results of our study highlight the utility of considering the phylogeographic relationships inferred from genome-wide SNPs when characterizing conservation units and management priorities, which is particularly relevant as genomic data sets become increasingly accessible.
Project description:Adhesives from marine organisms are often the source of inspiration for the development of glues able to create durable bonds in wet environments. In this work, we investigated the adhesive secretions produced by germlings of two large seaweed species from the South Pacific, Durvillaea antarctica, also named 'the strongest kelp in the word', and its close relative Hormosira banksii The comparative analysis was based on optical and scanning electron microscopy imaging as well as Fourier transform infrared (FTIR) spectroscopy and principal component analysis (PCA). For both species, the egg surface presents peripheral vesicles which are released soon after fertilization to discharge a primary adhesive. This is characterized by peaks representative of carbohydrate molecules. A secondary protein-based adhesive is then secreted in the early developmental stages of the germlings. Energy dispersive X-ray, FTIR and PCA indicate that D. antarctica secretions also contain sulfated moieties, and become cross-linked with time, both conferring strong adhesive and cohesive properties. On the other hand, H. banksii secretions are complemented by the putative adhesive phlorotannins, and are characterized by a simple mechanism in which all constituents are released with the same rate and with no apparent cross-linking. It is also noted that the release of adhesive materials appears to be faster and more copious in D. antarctica than in H. banksii Overall, this study highlights that both quantity and quality of the adhesives matter in explaining the superior attachment ability of D. antarctica.