14 research outputs found
Genetic diversity and cryptic population re-establishment: management implications for the Bojer's skink (Gongylomorphus bojerii)
Understanding genetic structure and diversity underpins the management of isolated populations. Small populations confined to islands may require effective genetic management for population persistence due to inbreeding and reduced genetic diversity. Endemic to the offshore islands of mainland Mauritius, the Bojerâs skink (Gongylomorphus bojerii) has previously been managed as two genetic units due to divergence between populations to the north and south-east. In 2009, a few individuals were discovered on the south-eastern island Ile de la Passe (IDLP), an island within its former range where the species was believed to have gone extinct. This island was later supplemented with translocations from other south-eastern islands, but individual geographic origin and the genetic consequences of these translocations remains unknown. Demographic population history and translocation events were reconstructed using a suite of microsatellite markers and the mitochondrial DNA cytochrome b gene, assessing two northern and three south-eastern populations to infer the geographic origin of the IDLP individuals, and to assess the populationâs genetic diversity and structure. Although IDLP showed significant differentiation from all other populations, all analyses indicated a south-eastern origin, possibly founded by a single gravid female. Subsequent translocations have so far failed to ameliorate IDLPâs genetic diversity. In addition, admixture analysis was used to track translocation and gene-flow in IDLP. We recommend using additional translocations from other south-eastern islands to further genetically support IDLP. Our study highlights the need to clarify cryptic population structure and utilise post-translocation genetic monitoring among similarly managed populations, particularly endangered island populations
The positive impact of conservation action
Governments recently adopted new global targets to halt and reverse the loss of biodiversity. It is therefore crucial to understand the outcomes of conservation actions. We conducted a global meta-analysis of 186 studies (including 665 trials) that measured biodiversity over time and compared outcomes under conservation action with a suitable counterfactual of no action. We find that in two-thirds of cases, conservation either improved the state of biodiversity or at least slowed declines. Specifically, we find that interventions targeted at species and ecosystems, such as invasive species control, habitat loss reduction and restoration, protected areas, and sustainable management, are highly effective and have large effect sizes. This provides the strongest evidence to date that conservation actions are successful but require transformational scaling up to meet global targets
Genetic swamping of the critically endangered Scottish wildcat was recent and accelerated by disease
The European wildcat population in Scotland is considered critically endangered as a result of hybridization
with introduced domestic cats,1,2 though the time frame over which this gene flow has taken place is unknown. Here, using genome data from modern, museum, and ancient samples, we reconstructed the trajectory and dated the decline of the local wildcat population from viable to severely hybridized. We demonstrate
that although domestic cats have been present in Britain for over 2,000 years,3 the onset of hybridization was
only within the last 70 years. Our analyses reveal that the domestic ancestry present in modern wildcats is
markedly over-represented in many parts of the genome, including the major histocompatibility complex
(MHC). We hypothesize that introgression provides wildcats with protection against diseases harbored
and introduced by domestic cats, and that this selection contributes to maladaptive genetic swamping
through linkage drag. Using the case of the Scottish wildcat, we demonstrate the importance of local
ancestry estimates to both understand the impacts of hybridization in wild populations and support conservation efforts to mitigate the consequences of anthropogenic and environmental chang
To unscramble an egg: admixed captive breeding populations can be rescued using local ancestry information
A Mitochondrial Phylogeny of the Sand Cat (Felis margarita Loche, 1858)
International audienc
A Mitochondrial Phylogeny of the Sand Cat (Felis margaritaLoche, 1858)
The sand cat,Felis margaritaLoche,1858,is a small desert cat with a fragmented distribution across the Sahara, Arabian Peninsula, and Central Asia. It is currently listed as Least Concern by the IUCN; however, its status in many countries is unknown. Sand cats are generally classified into four subspecies:F. m. margarita(North Africa and Sahara), F. m. harrisoni(Arabia),F. m. thinobia(Central Asia), andF. m. scheffeli(Pakistan). The aim of this study was to determine the validity of these subspecies using genetic analysis. Sequences from the mitochondrial control region, mitochondrial NADH subunit 5, and cytochromebgenes (643 bp) were generated in a sample set of 47 animals of known geographical origin, from across the sand cat's range over the past 100 years. The results of the analysis suggest some degree of genetic differentiation between the African populations (F. m. margarita) and those of Arabian or Central Asian origin, which merits further investigation with nuclear loci and further sampling of intermediate geographical locations. There is little genetic justification for differentiation of the other proposed subspecies (F. m. harrisoni, F. m. thinobia,andF. m. scheffeli), which differ only by 1-3 bp mutations in their haplotypes. The genetic diversity of a set of 86 captive sand cat samples is also generated and compared to facilitate future conservation management of the species in captivity
A Mitochondrial Phylogeny of the Sand Cat (Felis margarita Loche, 1858)
The sand cat, Felis margarita Loche, 1858, is a small desert cat with a fragmented distribution across the Sahara, Arabian Peninsula, and Central Asia. It is currently listed as Least Concern by the IUCN; however, its status in many countries is unknown. Sand cats are generally classified into four subspecies: F. m. margarita (North Africa and Sahara), F. m. harrisoni (Arabia), F. m. thinobia (Central Asia), and F. m. scheffeli (Pakistan). The aim of this study was to determine the validity of these subspecies using genetic analysis. Sequences from the mitochondrial control region, mitochondrial NADH subunit 5, and cytochrome b genes (643 bp) were generated in a sample set of 47 animals of known geographical origin, from across the sand catâs range over the past 100 years. The results of the analysis suggest some degree of genetic differentiation between the African populations (F. m. margarita) and those of Arabian or Central Asian origin, which merits further investigation with nuclear loci and further sampling of intermediate geographical locations. There is little genetic justification for differentiation of the other proposed subspecies (F. m. harrisoni, F. m. thinobia, and F. m. scheffeli), which differ only by 1â3 bp mutations in their haplotypes. The genetic diversity of a set of 86 captive sand cat samples is also generated and compared to facilitate future conservation management of the species in captivity
Alemtuzumab versus interferon beta 1a as first-line treatment for patients with relapsing-remitting multiple sclerosis: a randomised controlled phase 3 trial
Background The anti-CD52 monoclonal antibody alemtuzumab reduced disease activity in a phase 2 trial of previously untreated patients with relapsing-remitting multiple sclerosis. We aimed to assess efficacy and safety of first-line alemtuzumab compared with interferon beta 1a in a phase 3 trial