Characterization of Mauritius parakeet (Psittacula eques) microsatellite loci and their cross-utility in other parrots (Psittacidae, Aves).

We characterized 21 polymorphic microsatellite loci in the endangered Mauritius parakeet (Psittacula eques). Loci were isolated from a Mauritius parakeet genomic library that had been enriched separately for eight different repeat motifs. Loci were characterized in up to 43 putatively unrelated Mauritius parakeets from a single population inhabiting the Black River Gorges National Park, Mauritius. Each locus displayed between three and nine alleles, with the observed heterozygosity ranging between 0.39 and 0.96. All loci were tested in 10 other parrot species. Despite testing few individuals, between seven and 21 loci were polymorphic in each of seven species tested

Widespread gene flow between oceans in a pelagic seabird species complex

Global-scale gene flow is an important concern in conservation biology as it has the potential to either increase or decrease genetic diversity in species and populations. Although many studies focus on the gene flow between different populations of a single species, the potential for gene flow and introgression between species is understudied, particularly in seabirds. The only well studied example of a mixed-species, hybridising population of petrels exists on Round Island, in the Indian Ocean. Previous research assumed that Round Island represents a point of secondary contact between Atlantic (Pterodroma arminjoniana) and Pacific species (P. neglecta and P. heraldica). This study uses microsatellite genotyping and tracking data to address the possibility of between-species hybridisation occurring outside the Indian Ocean. Dispersal and gene flow spanning three oceans was demonstrated between the species in this complex. Analysis of migration rates estimated using BAYESASS revealed unidirectional movement of petrels from the Atlantic and Pacific into the Indian Ocean. Conversely, STRUCTURE analysis revealed gene-flow between species of the Atlantic and Pacific Oceans, with potential three-way hybrids occurring outside the Indian Ocean. Additionally, geolocation tracking of Round Island petrels revealed two individuals travelling to the Atlantic and Pacific. These results suggest that inter-specific hybrids in Pterodroma petrels are more common than was previously assumed. This study is the first of its kind to investigate gene flow between populations of closely related Procellariform species on a global scale, demonstrating the need for consideration of widespread migration and hybridisation in the conservation of threatened seabirds

Tripartite polyionic complex (PIC) micelles as non-viral vectors for mesenchymal stem cell siRNA transfection

International audienc

Spatial genetic architecture of the critically-endangered Maui Parrotbill (Pseudonestor xanthophrys): management considerations for reintroduction strategies

Conservation translocations are an important tool to circumvent extinctions on oceanic islands. A thorough understanding of all components of a species’ biology, including genetic diversity and structure, can maximize their likelihood of success. The Maui Parrotbill (Pseudonestor xanthophrys) is an endangered Hawaiian honeycreeper endemic to the island of Maui. With a population of approximately 500 individuals restricted to 50 km2 of habitat, this species is at high risk of extinction. Using nuclear and mitochondrial DNA, this study quantified the levels of genetic diversity and structure in wild and captive parrotbill populations, and compared these genetic patterns to those observed within levels of contemporary and historical nuclear diversity derived from 100-year old museum samples. Substantial differences in the effective population sizes estimated between contemporary and historical parrotbill populations highlight the impact that introduced disease had on this species just before the turn of the century. Contemporary parrotbill diversity was low (global F st = 0.056), and there has been a 96 % reduction in genetic effective population size between contemporary and historical samples. This should not eliminate a conservation translocation (or reintroduction) as a viable recovery option. Measures of population differentiation (pairwise F st and R st ) between different sections of the current population on either side of the Koolau Gap suggest that current genetic structure may be the result of this topographic barrier to gene flow. These data can enable the design of a conservation translocation strategy that is tailored to the patterns of genetic structure across the species’ range

Long-term, fine-scale temporal patterns of genetic diversity in the restored Mauritius parakeet reveal genetic impacts of management and associated demographic effects on reintroduction programmes

Threatened populations of birds are often restored after bottleneck events by using reintroduction techniques. Whilst population numbers are often increased by using such measures, the long-term genetic effects of reintroductions and post-release management of the resulting populations are frequently overlooked. We identify an overall declining trend in population-wide estimates of genetic diversity over two decades since the initial recovery of the population from the most severe part of this species’ bottleneck. Additionally, by incorporating the genotypes of known founding individuals into population viability simulations, we evaluate the genetic effects of population management under various scenarios at both the metapopulation and subpopulation levels. We reveal that whilst population augmentation has led to increased genetic homogenisation among subpopulations, significant differentiation still exists. Simulations predict that even with a low level of natural dispersal leading to gene-flow this differentiation could be ameliorated. We conclude by offering a number of key recommendations relating to post-recovery management of reintroduced bird populations which support the encouragement of individual dispersal using established management techniques such as artificial nest-site provisioning

Pterodroma microsatellite genotype dataset

Genotypes for Pterodroma petrels generated in GeneMapper from final set of 12 autosomal microsatellite markers. Used in the manuscript for structure and gene flow analysis

State of art and limitations in genetic engineering to induce stable chondrogenic phenotype

International audienceCurrent protocols for chondrocyte expansion and chondrogenic differentiation of stem cells fail to reduce phenotypic loss and to mitigate hypertrophic tendency. To this end, cell genetic manipulation is gaining pace as a means of generating cells with stable chondrocyte phenotype. Herein, we provide an overview of candidate genes that either induce cartilage regeneration or inhibit cartilage degeneration. We further discuss in vitro, ex vivo and in vivo viral transduction and non-viral transfection strategies for targeted cells (chondrocytes, me-senchymal stem cells, induced pluripotent stem cells and synovial cells), along with the most representative results obtained in pre-clinical models and in clinical trials. We highlight current challenges and associated risks that slowdown clinical acceptance and commercialisation of gene transfer technologies