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1.
Sci Rep ; 13(1): 6718, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-37185616

RESUMEN

Quantitative assessments of endemism, evolutionary distinctiveness and extinction threat underpin global conservation prioritization for well-studied taxa, such as birds, mammals, and amphibians. However, such information is unavailable for most of the world's taxa. This is the case for the Orchidaceae, a hyperdiverse and cosmopolitan family with incomplete phylogenetic and threat information. To define conservation priorities, we present a framework based on phylogenetic and taxonomic measures of distinctiveness and rarity based on the number of regions and the area of occupancy. For 25,434 orchid species with distribution data (89.3% of the Orchidaceae), we identify the Neotropics as hotspots for richness, New Guinea as a hotspot for evolutionary distinctiveness, and several islands that contain many rare and distinct species. Orchids have a similar proportion of monotypic genera as other Angiosperms, however, more taxonomically distinct orchid species are found in a single region. We identify 278 species in need of immediate conservation actions and find that more than 70% of these do not currently have an IUCN conservation assessment and are not protected in ex-situ collections at Botanical Gardens. Our study highlights locations and orchid species in urgent need of conservation and demonstrates a framework that can be applied to other data-deficient taxa.


Asunto(s)
Conservación de los Recursos Naturales , Orchidaceae , Animales , Biodiversidad , Filogenia , Orchidaceae/genética , Evolución Biológica , Mamíferos
2.
Trends Plant Sci ; 28(7): 731-733, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37188556

RESUMEN

China has an in situ conservation system built around national parks, and has begun establishing an ex situ conservation system led by National Botanical Gardens. We highlight how this National Botanical Gardens system will serve the global biodiversity conservation goal of harmonious coexistence between humans and nature.


Asunto(s)
Conservación de los Recursos Naturales , Desarrollo Sostenible , Humanos , Plantas , Biodiversidad , China
3.
Trends Plant Sci ; 28(8): 913-923, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37142532

RESUMEN

Despite the importance of plants for humans and the threats to their future, plant conservation receives far less support compared with vertebrate conservation. Plants are much cheaper and easier to conserve than are animals, but, although there are no technical reasons why any plant species should become extinct, inadequate funding and the shortage of skilled people has created barriers to their conservation. These barriers include the incomplete inventory, the low proportion of species with conservation status assessments, partial online data accessibility, varied data quality, and insufficient investment in both in and ex situ conservation. Machine learning, citizen science (CS), and new technologies could mitigate these problems, but we need to set national and global targets of zero plant extinction to attract greater support.


Asunto(s)
Biodiversidad , Embryophyta , Animales , Humanos , Conservación de los Recursos Naturales , Plantas
4.
J Biomed Opt ; 28(3): 036009, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-37009577

RESUMEN

Significance: As many as 60% of patients with early stage breast cancer undergo breast-conserving surgery. Of those, 20% to 35% need a second surgery because of incomplete resection of the lesions. A technology allowing in situ detection of cancer could reduce re-excision procedure rates and improve patient survival. Aim: Raman spectroscopy was used to measure the spectral fingerprint of normal breast and cancer tissue ex-vivo. The aim was to build a machine learning model and to identify the biomolecular bands that allow one to detect invasive breast cancer. Approach: The system was used to interrogate specimens from 20 patients undergoing lumpectomy, mastectomy, or breast reduction surgery. This resulted in 238 ex-vivo measurements spatially registered with standard histology classifying tissue as cancer, normal, or fat. A technique based on support vector machines led to the development of predictive models, and their performance was quantified using a receiver-operating-characteristic analysis. Results: Raman spectroscopy combined with machine learning detected normal breast from ductal or lobular invasive cancer with a sensitivity of 93% and a specificity of 95%. This was achieved using a model based on only two spectral bands, including the peaks associated with C-C stretching of proteins around 940 cm - 1 and the symmetric ring breathing at 1004 cm - 1 associated with phenylalanine. Conclusions: Detection of cancer on the margins of surgically resected breast specimen is feasible with Raman spectroscopy.


Asunto(s)
Neoplasias de la Mama , Carcinoma Ductal de Mama , Humanos , Femenino , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/cirugía , Espectrometría Raman/métodos , Mastectomía , Mastectomía Segmentaria/métodos , Proteínas , Carcinoma Ductal de Mama/cirugía
5.
J Hered ; 114(3): 259-270, 2023 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-37002622

RESUMEN

Hibiscus liliiflorus, endemic to the Indian Ocean island of Rodrigues, is one of the rarest plant species in the world; only 2 wild individuals remain. Previously, when 4 wild individuals remained, the Mauritian Wildlife Foundation (MWF) in Rodrigues propagated cuttings of them in their nursery, then planted seedlings produced in the nursery into 3 outplanted populations on the island. Our goals were to: 1) assess whether all 4 original wild genotypes are represented in the MWF nursery; 2) determine whether ex situ living collections at international botanical gardens maintain unique genotypes of H. liliiflorus; 3) assess whether nursery individuals have crossed or self-fertilized to produce seed and quantify their relative contributions to outplanted populations; and 4) provide recommendations for future conservation actions. We used a 2b-RADseq approach to produce 2,711 genome-wide single nucleotide polymorphisms (SNPs) from 98 samples. Genotype identity analysis, principal component analysis, and model-based clustering in STRUCTURE found 4 genotypes extant in Rodrigues but no unique genotypes in ex situ botanic garden collections. Only 3 genotypes are represented in the MWF nursery; the one remaining genotype is represented by an extant wild individual. Parentage analysis showed that seeds produced in the MWF nursery resulted from both self-fertilization and crossing between genotypes, a result supported by internal relatedness and hybrid index calculations. Each outplanted population is dominated by a subset of parental genotypes, and we propose actions to balance the parental contributions to outplanted populations. Our study highlights how genetic assessments of ex situ conservation projects help conserve critically endangered species.


Asunto(s)
Conservación de los Recursos Naturales , Hibiscus , Humanos , Animales , Hibiscus/genética , Especies en Peligro de Extinción , Plantas , Genotipo
6.
Proc Natl Acad Sci U S A ; 120(14): e2205768119, 2023 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-36972434

RESUMEN

The resilience and sustainability of food systems depend on crop diversity. It is used by breeders to produce new and better varieties, and by farmers to respond to new challenges or demands and to spread risk. However, crop diversity can only be used if it has been conserved, can be identified as the solution for a given problem, and is available. As the ways in which crop diversity is used in research and breeding change and expand, the global conservation system for crop diversity must keep pace; it must provide not only the biological materials themselves, but also the relevant information presented in a comprehensive and coherent way-all while ensuring equitable access and benefit sharing. Here we explore the evolving priorities for global efforts to safeguard and make available the diversity of the world's crops through ex situ genetic resource collections. We suggest that collections held by academic institutions and other holders that are not standard gene banks should be better integrated in global efforts and decision-making to conserve genetic resources. We conclude with key actions that we suggest should be taken to ensure that crop diversity collections of all types are able to fulfill their role to foster more diverse, equitable, resilient, and sustainable food systems globally.


Asunto(s)
Conservación de los Recursos Naturales , Fitomejoramiento , Productos Agrícolas/genética , Responsabilidad Social
7.
Conserv Biol ; : e14065, 2023 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-36811200

RESUMEN

A range of conservation and restoration tools are needed to safeguard the structure and function of aquatic ecosystems. Aquaculture, the culturing of aquatic organisms, often contributes to the numerous stressors that aquatic ecosystems face, yet some aquaculture activities can also deliver ecological benefits. We reviewed the literature on aquaculture activities that may contribute to conservation and restoration outcomes, either by enhancing the persistence or recovery of one or more target species or by moving aquatic ecosystems toward a target state. We identified 12 ecologically beneficial outcomes achievable via aquaculture: species recovery, habitat restoration, habitat rehabilitation, habitat protection, bioremediation, assisted evolution, climate change mitigation, wild harvest replacement, coastal defense, removal of overabundant species, biological control, and ex situ conservation. This list may be expanded as new applications are discovered. Positive intentions do not guarantee positive ecological outcomes, so it is critical that potentially ecologically beneficial aquaculture activities be evaluated via clear and measurable indicators of success to reduce potential abuse by greenwashing. Unanimity on outcomes, indicators, and related terminology will bring the field of aquaculture-environment interactions into line with consensus standards in conservation and restoration ecology. Broad consensus will also aid the development of future certification schemes for ecologically beneficial aquaculture.


Se necesita una gama de herramientas de conservación y restauración para salvaguardar la estructura y función de los ecosistemas acuáticos. La acuacultura (el cultivo de organismos acuáticos) generalmente contribuye a los numerosos estresantes que soportan los ecosistemas acuáticos, aunque algunas actividades de la acuacultura también pueden proporcionar beneficios ecológicos. Revisamos la literatura sobre las actividades de acuacultura que pueden contribuir a los resultados de conservación y restauración, ya sea al incrementar la persistencia o recuperación de una o más especies objetivo o al llevar a los ecosistemas acuáticos hacia un estado objetivo. Identificamos doce resultados con beneficios ecológicos que pueden lograrse con la acuacultura: recuperación de la especie, recuperación del hábitat, restauración del hábitat, rehabilitación del hábitat, protección del hábitat, bioreparación, evolución asistida, mitigación del cambio climático, sustitución de la captura silvestre, defensa costera, eliminación de las especies sobreabundantes, control biológico y conservación ex situ. Esta lista puede expandirse conforme se descubren nuevas aplicaciones. Las intenciones positivas no garantizan resultados ecológicos positivos, así que es importante que se evalúen las actividades de acuacultura con un posible beneficio ecológico por medio de indicadores del éxito claros y medibles para reducir el abuso potencial por ecoblanqueo o greenwashing. La unanimidad en los resultados, indicadores y terminología relacionada armonizará las interacciones entre la acuacultura y el ambiente con los estándares de la conservación y la ecología de la restauración. Un consenso generalizado también ayudará con el desarrollo de futuros esquemas de certificación para la acuacultura con beneficios ecológicos. Obtención de resultados de conservación y restauración a través de la acuacultura con beneficios ecológicos.

8.
Genes (Basel) ; 14(1)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36672915

RESUMEN

Plant genetic resources (PGRs) are the total hereditary material, which includes all the alleles of various genes, present in a crop species and its wild relatives. They are a major resource that humans depend on to increase farming resilience and profit. Hence, the demand for genetic resources will increase as the world population increases. There is a need to conserve and maintain the genetic diversity of these valuable resources for sustainable food security. Due to environmental changes and genetic erosion, some valuable genetic resources have already become extinct. The landraces, wild relatives, wild species, genetic stock, advanced breeding material, and modern varieties are some of the important plant genetic resources. These diverse resources have contributed to maintaining sustainable biodiversity. New crop varieties with desirable traits have been developed using these resources. Novel genes/alleles linked to the trait of interest are transferred into the commercially cultivated varieties using biotechnological tools. Diversity should be maintained as a genetic resource for the sustainable development of new crop varieties. Additionally, advances in biotechnological tools, such as next-generation sequencing, molecular markers, in vitro culture technology, cryopreservation, and gene banks, help in the precise characterization and conservation of rare and endangered species. Genomic tools help in the identification of quantitative trait loci (QTLs) and novel genes in plants that can be transferred through marker-assisted selection and marker-assisted backcrossing breeding approaches. This article focuses on the recent development in maintaining the diversity of genetic resources, their conservation, and their sustainable utilization to secure global food security.


Asunto(s)
Conservación de los Recursos Naturales , Productos Agrícolas , Humanos , Animales , Productos Agrícolas/genética , Fitomejoramiento , Especies en Peligro de Extinción , Variación Genética/genética
9.
Zoo Biol ; 42(3): 429-439, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36536594

RESUMEN

Zoo-based (ex situ) conservation breeding programs provide invaluable opportunities to uncover enigmatic behaviors and traits of focal species under managed care, which can support research and conservation management efforts. A suite of factors and a limited range have yielded population declines in the threatened narrow-headed gartersnake (Thamnophis rufipunctatus). Better understanding its cryptic ecology and life history (e.g., reproductive ecology) offers conservation benefits. We analyzed data on courtship behavior, parity and litter size, offspring size, and neonatal growth from an ex situ T. rufipunctatus population at the Phoenix Zoo from 2009 to 2018. Courtship behavior and parturition phenology are likely linked with the North American monsoon season, yet the courtship window may be wider than realized. We document the first instances of interannual iteroparity and multigenerational rearing of successful breeders at the ex situ level. Litter sizes varied but were relative to maternal body mass, suggesting that fecundity may be driven by intrinsic condition (e.g., age and size) of breeding females. Mean offspring body masses were equivalent between sexes, and neonate growth trends were quadratic during their first 9 months. Sexual dimorphism became apparent around 4-5 months age. Much of these data are novel for T. rufipunctatus and provide insight into their reproductive ecology. Phenology of reproductive ecology and body size metrics can guide field surveillance, age estimations, and population ecology monitoring, as well as inform ex situ adaptive management practices. Strategies spanning the ex situ-in situ spectrum are applicable to other imperiled taxa to better inform conservation management decisions.


Asunto(s)
Colubridae , Especies en Peligro de Extinción , Femenino , Animales , Conservación de los Recursos Naturales , Animales de Zoológico , Reproducción
10.
Rev. colomb. biotecnol ; 24(2): 68-76, jul.-dic. 2022. tab, graf
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1423776

RESUMEN

RESUMEN Neltuma alba Griseb es una especie emblemática de la Ecorregión Chaqueña, por el valor de su madera y frutos. Los resultados de la presente investigación, dan cuenta de que las semillas de algarrobo blanco pueden ser críoconservadas sin afectar el poder y la energía para germinar. Las semillas fueron conservadas por tres meses a Temperatura ambiente (24° y 30°C, Congelamiento (-18°C) y Nitrógeno líquido (-196°C). Posteriormente, fueron escarificadas mecánicamente y sembradas en tierra negra y aserrín (3:1). Los resultados fueron sometidos a pruebas no paramétricas de Kruskal-Wallis, analizándose poder, energía y vigor germinativo, y no se detectaron diferencias significativas entre tratamientos. Para la regeneración in vitro en medio de cultivo MS suplementados con 3 mg L-1 IBA y 0,05 mg L-1 CIN, se utilizaron segmentos nodales de 2 cm de longitud obtenidos de plántulas provenientes de semillas. Los porcentajes de enraizamiento obtenidos fueron elevados (87-90%). No existiendo diferencias significativas entre los tratamientos ensayados. El almacenamiento de semillas a 24°-30°C resulta ser el más apropiado para alcanzar altos porcentajes de germinación


ABSTRACT Neltuma alba Gris is an emblematic specie of Chaco Ecoregion for its wood and fruits value. This research show that algarrobo blanco's seeds can cryopreserve without affecting germination power and energy. The seeds were kept for three months at 24°-30°C, (-18°C) and (-196°C). Later, they were mechanically scarified and sown in black soil and sawdust (3: 1). The results were subjected to non-parametric Kruskal-Wallis tests, analyzing germination power, energy and vigor. The test did not detect significant differences between treatments. The nodal segments (2 cm long) obtained from plants of seeds were used for in vitro regeneration in MS culture medium supplemented with 3 mg L-1 IBA and 0.05 mg L-1 CIN, The rooting percentages obtained were high (87-90%). There are no significant differences between treatments tested. The storage of seeds at 24°-30°C is the most approppiate to rich high percentages of germination.

11.
Theriogenology ; 191: 141-152, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35986940

RESUMEN

The establishment and management of ex situ breeding and assurance populations around the globe are meant to provide short-term solutions to the formidable loss of amphibian diversity presently occurring. Large multi-scaled facilities, such as zoos and aquariums, can provide the infrastructure to safeguard species and populations. However, often even large, economically viable facilities lack the knowledge to efficiently cater to the plethora of environmentally controlled physiological strategies that amphibians possess. Anurans present a class of amphibians that have often been viewed as easy to maintain ex situ. However, while adult survival may be relatively successful it is rarely accompanied by good reproductive output, health, and fitness. Even more conspicuous is the low survivorship of offspring produced ex situ once they are translocated back into the wild. The mountain yellow-legged frog (R. muscosa) ex situ breeding program EBP is a prime example of the challenges that amphibians EBPs face. Although more research is needed, the R. muscosa program has increased reproductive output and health of its colony by incorporating reproductive technologies and strategic genetic management in conjunction with a greater understanding of the species' natural history, to produce and translocate viable animals each year. This paper highlights the EBPs past decade of research featuring the program's contribution to building empirical, multidisciplinary approaches that boost the robustness of an endangered species, by safeguarding existing genetic diversity and maximizing fitness and survival outcomes.


Asunto(s)
Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Animales , Anuros/genética , Reproducción , Técnicas Reproductivas/veterinaria
12.
Reprod Fertil ; 3(3): R121-R146, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35928671

RESUMEN

Biodiversity is defined as the presence of a variety of living organisms on the Earth that is essential for human survival. However, anthropogenic activities are causing the sixth mass extinction, threatening even our own species. For many animals, dwindling numbers are becoming fragmented populations with low genetic diversity, threatening long-term species viability. With extinction rates 1000-10,000 times greater than natural, ex situ and in situ conservation programmes need additional support to save species. The indefinite storage of cryopreserved (-196°C) viable cells and tissues (cryobanking), followed by assisted or advanced assisted reproductive technology (ART: utilisation of oocytes and spermatozoa to generate offspring; aART: utilisation of somatic cell genetic material to generate offspring), may be the only hope for species' long-term survival. As such, cryobanking should be considered a necessity for all future conservation strategies. Following cryopreservation, ART/aART can be used to reinstate lost genetics back into a population, resurrecting biodiversity. However, for this to be successful, species-specific protocol optimisation and increased knowledge of basic biology for many taxa are required. Current ART/aART is primarily focused on mammalian taxa; however, this needs to be extended to all, including to some of the most endangered species: amphibians. Gamete, reproductive tissue and somatic cell cryobanking can fill the gap between losing genetic diversity today and future technological developments. This review explores species prioritisation for cryobanking and the successes and challenges of cryopreservation and multiple ARTs/aARTs. We here discuss the value of cryobanking before more species are lost and the potential of advanced reproductive technologies not only to halt but also to reverse biodiversity loss. Lay summary: The world is undergoing its sixth mass extinction; however, unlike previous events, the latest is caused by human activities and is resulting in the largest loss of biodiversity (all living things on Earth) for 65 million years. With an extinction rate 1000-10,000-fold greater than natural, this catastrophic decline in biodiversity is threatening our own survival. As the number of individuals within a species declines, genetic diversity reduces, threatening their long-term existence. In this review, the authors summarise approaches to indefinitely preserve living cells and tissues at low temperatures (cryobanking) and the technologies required to resurrect biodiversity. In the future when appropriate techniques become available, these living samples can be thawed and used to reinstate genetic diversity and produce live young ones of endangered species, enabling their long-term survival. The successes and challenges of genome resource cryopreservation are discussed to enable a move towards a future of stable biodiversity.


Asunto(s)
Bancos de Muestras Biológicas , Conservación de los Recursos Naturales , Animales , Biodiversidad , Especies en Peligro de Extinción , Humanos , Masculino , Mamíferos , Técnicas Reproductivas Asistidas
13.
PLoS One ; 17(8): e0272929, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35969623

RESUMEN

Because of species diversity and troubling conservation status in the wild, Orchidaceae has been one of the taxa with most concern in population ecological research for a long time. Although Orchidaceae is a group with high adaptability, they have become endangered for complex and various reasons such as the germination? difficulty and habitat loss, which makes it difficult to develop an accurate protection strategy. Phaius flavus is a terrestrial orchid which used to be widely distributed in central and southern Asia; however, large populations are difficult to find in the wild. Thus, the aim of this study was to provide a new perspective for conserving endangered P. flavus by investigating the mechanisms of its population decline; we established time-specific life and fertility tables, age pyramids, survival curves, and mortality curves for this plant and then conducted Leslie matrix model. We found that both of the populations from Wuhu Mount (WM) and Luohan Mount (LM) showed declining trends and exhibited pot-shaped age pyramids, low net reproductive rates, and negative intrinsic growth rates. The population from the Beikengding Mount (BM) showed a stable status with a bell-shaped age pyramid. However, it has a significant risk of decline because of the low net reproductive rate and intrinsic growth rate. This study use time-specific life and fertility tables, age pyramids, survival curves, and mortality curves, showed that the population decline of P. flavus could be attributed to 1) the shortage of seedlings caused by the low germination rate in the wild and 2) the loss of adult individuals caused by anthropogenic disturbances. To protect this species from extinction in these areas, we suggest that human activities in these habitats should be strictly forbidden and ex situ conservation of this plant in botanical gardens is also necessary.


Asunto(s)
Conservación de los Recursos Naturales , Orchidaceae , Animales , China , Ecosistema , Humanos , Plantas , Dinámica Poblacional
14.
Sci Total Environ ; 843: 157011, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-35772549

RESUMEN

The Chinese sturgeon, an important endemism of the Yangtze River, belongs to 'the most critically endangered group of species' worldwide, with overfishing and habitat destruction being the main drivers towards extinction. Newly obtained microchemical comparisons between animals and water from different river locations revealed a probable shifting of the spawning ground few kilometers downstream compared to the only previously known site, located under the Gezhouba Dam. This offers a glimmer of hope for an adaptive response to habitat perturbation caused by the recently built Three Gorges dam on the Yangtze River. On the other hand, genetic data provide an estimate of about 20 breeders participating in the only significant breeding event of the past 10 years. This warns of a near species extinction forecast if no in situ and ex situ conservation efforts occur promptly. Given these results we propose a list of priority conservation actions that urgently need to be promoted, supported, and put into practice.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Animales , China , Peces/fisiología , Ríos
15.
Ann Bot ; 129(7): 857-868, 2022 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-35670810

RESUMEN

BACKGROUND AND AIMS: Habitat degradation and landscape fragmentation dramatically lower population sizes of rare plant species. Decreasing population sizes may, in turn, negatively affect genetic diversity and reproductive fitness, which can ultimately lead to local extinction of populations. Although such extinction vortex dynamics have been postulated in theory and modelling for decades, empirical evidence from local extinctions of plant populations is scarce. In particular, comparisons between current vs. historical genetic diversity and differentiation are lacking despite their potential to guide conservation management. METHODS: We studied the population genetic signatures of the local extinction of Biscutella laevigata subsp. gracilis populations in Central Germany. We used microsatellites to genotype individuals from 15 current populations, one ex situ population, and 81 herbarium samples from five extant and 22 extinct populations. In the current populations, we recorded population size and fitness proxies, collected seeds for a germination trial and conducted a vegetation survey. The latter served as a surrogate for habitat conditions to study how habitat dissimilarity affects functional connectivity among the current populations. KEY RESULTS: Bayesian clustering revealed similar gene pool distribution in current and historical samples but also indicated that a distinct genetic cluster was significantly associated with extinction probability. Gene flow was affected by both the spatial distance and floristic composition of population sites, highlighting the potential of floristic composition as a powerful predictor of functional connectivity which may promote decision-making for reintroduction measures. For an extinct population, we found a negative relationship between sampling year and heterozygosity. Inbreeding negatively affected germination. CONCLUSIONS: Our study illustrates the usefulness of historical DNA to study extinction vortices in threatened species. Our novel combination of classical population genetics together with data from herbarium specimens, an ex situ population and a germination trial underlines the need for genetic rescue measures to prevent extinction of B. laevigata in Central Germany.


Asunto(s)
Flujo Génico , Genética de Población , Teorema de Bayes , Conservación de los Recursos Naturales , Extinción Biológica , Variación Genética , Endogamia , Densidad de Población
16.
Conserv Biol ; 36(4): e13918, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35554972

RESUMEN

The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400-480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993-2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations.


La paloma rosada (Nesoenas mayeri) es una especie endémica de Mauricio que se ha recuperado impresionantemente después de un grave cuello de botella poblacional a principios de la década de 1970 que duró hasta inicios de la década de 1990. Antes de este cuello de botella se había establecido una población ex situ de la cual se liberaban individuos reproducidos en cautiverio a las subpoblaciones en libertad para incrementar la variación genética y el tamaño poblacional. Este rescate de conservación derivó en una recuperación rápida de la población (400-480 individuos) y la especie cambió positivamente de categoría dos veces en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN). Analizamos los impactos del cuello de botella y el rescate genético sobre la variación genética neutral durante y después de la recuperación poblacional (de 1993 a 2008) mediante secuenciación RAD, análisis de microsatélites y análisis genéticos cuantitativos de los datos del libro genealógico de 1112 aves ubicadas en zoológicos de Europa y los Estados Unidos. Usamos simulaciones por computadora para estudiar los cambios pronosticados en la variación genética y en la viabilidad poblacional del pasado hacia el futuro. La variación genética declinó rápidamente, a pesar de la recuperación poblacional, y el tamaño efectivo de la población fue aproximadamente un orden de magnitud más pequeño que el tamaño del censo. La especie contó con una carga genética elevada de casi 15 equivalentes letales para la longevidad. Nuestras simulaciones pronostican que la endogamia continua probablemente resultará en un incremento en la expresión de mutaciones deletéreas (es decir, una carga realizada elevada) y en una depresión endogámica severa. Sin acciones continuas para la conservación, es probable que la paloma rosada esté extinta en vida libre dentro de cien años. El rescate de conservación de la paloma rosada ha sido fundamental en la recuperación de la población silvestre; sin embargo, se requiere de un rescate genético adicional con las aves de reproducción en cautiverio de los zoológicos para recuperar la variación perdida, reducir la expresión de la variación deletérea dañina y prevenir la extinción. El uso de la genómica y los datos modelados puede orientar las valoraciones de la UICN sobre la viabilidad y el riesgo de extinción de las especies, además de que ayuda en la evaluación de la dependencia que tienen las poblaciones de la conservación.


Asunto(s)
Aves , Conservación de los Recursos Naturales , Animales , Aves/genética , Especies en Peligro de Extinción , Europa (Continente) , Variación Genética , Genómica , Densidad de Población
17.
Sci Rep ; 12(1): 8740, 2022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35610259

RESUMEN

Erymnochelys madagascariensis is a Critically Endangered turtle endemic to Madagascar. Anthropogenic activity has depleted the wild population by 70% in the last century, and effective conservation management is essential to ensuring its persistence. Captive breeding was implemented to augment depleted populations in the southern part of Ankarafantsika National Park (ANP), when no genetic data were available for E. madagascariensis. It is unknown how much of the natural population's diversity is encapsulated in captivity. We used eight microsatellite loci and fragments of two mitochondrial genes to identify the genetic structure of E. madagascariensis in the wild. Captive bred turtles were compared with wild populations in order to assess the representativeness of this ex situ conservation strategy for ANP. Six microsatellite clusters, ten cytochrome b, and nine COI haplotypes were identified across wild populations, with high genetic divergence found between populations in two groups of watersheds. Captive bred individuals represent three out of six sampled microsatellite clusters found in the wild and just one mitochondrial haplotype, possibly due to genetic drift. To improve genetic representation, the strategy of frequent interchange between captive and wild breeders within ANP should be revitalised and, as originally planned, hatchlings or juveniles should not be released beyond ANP.


Asunto(s)
Tortugas , Animales , Factor Natriurético Atrial/genética , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Variación Genética , Genética de Población , Haplotipos , Madagascar , Repeticiones de Microsatélite/genética , Tortugas/genética
18.
PLoS One ; 17(4): e0266244, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35390021

RESUMEN

Many endangered species exist in only a single population, and almost all species that go extinct will do so from their last remaining population. Understanding how to best conserve these single population threatened species (SPTS) is therefore a distinct and important task for threatened species conservation science. As a last resort, managers of SPTS may consider taking the entire population into captivity-ex situ, in toto conservation. In the past, this choice has been taken to the great benefit of the SPTS, but it has also lead to catastrophe. Here, we develop a decision-support tool for planning when to trigger this difficult action. Our method considers the uncertain and ongoing decline of the SPTS, the possibility that drastic ex situ action will fail, and the opportunities offered by delaying the decision. Specifically, these benefits are additional time for ongoing in situ actions to succeed, and opportunities for the managers to learn about the system. To illustrate its utility, we apply the decision tool to four retrospective case-studies of declining SPTS. As well as offering support to this particular decision, our tool illustrates why trigger points for difficult conservation decisions should be formulated in advance, but must also be adaptive. A trigger-point for the ex situ, in toto conservation of a SPTS, for example, will not take the form of a simple threshold abundance.


Asunto(s)
Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Animales , Conservación de los Recursos Naturales/métodos , Estudios Retrospectivos , Puntos Disparadores
19.
Mol Biol Rep ; 49(5): 4107-4114, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35359235

RESUMEN

BACKGROUND: Genetics driven interventions if adopted in conservation breeding projects may enhance the overall success by prioritizing breeding among genetically most competent individuals and delaying or completely diminishing the ill effects of inbreeding. METHODS AND RESULTS: In the present study, we investigated genetic make-up of 15 tigers housed at five different captive facilities of West Bengal in India and report the moderate level of genetic variation. We identified five tigers based on individual genetic attributes that may be prioritized for future breeding or animal exchange programmes. The occurrence of first and second order related individuals in captivity require management attention and they should be paired considering their immediate genetic background. CONCLUSION: Considering tiger as a case study, we highlight the use of genetic assessment and necessity to validate the studbook records in formulating adaptive management strategies for long-term conservation and management of species of interest.


Asunto(s)
Tigres , Animales , Conservación de los Recursos Naturales/métodos , ADN , Antecedentes Genéticos , Variación Genética , Endogamia , Tigres/genética
20.
Conserv Biol ; 36(4): e13889, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35023224

RESUMEN

Restoration programs in the form of ex-situ breeding combined with reintroductions are becoming critical to counteract demographic declines and species losses. Such programs are increasingly using genetic management to improve conservation outcomes. However, the lack of long-term monitoring of genetic indicators following reintroduction prevents assessments of the trajectory and persistence of reintroduced populations. We carried out an extensive monitoring program in the wild for a threatened small-bodied fish (southern pygmy perch, Nannoperca australis) to assess the long-term genomic effects of its captive breeding and reintroduction. The species was rescued prior to its extirpation from the terminal lakes of Australia's Murray-Darling Basin, and then used for genetically informed captive breeding and reintroductions. Subsequent annual or biannual monitoring of abundance, fitness, and occupancy over a period of 11 years, combined with postreintroduction genetic sampling, revealed survival and recruitment of reintroduced fish. Genomic analyses based on data from the original wild rescued, captive born, and reintroduced cohorts revealed low inbreeding and strong maintenance of neutral and candidate adaptive genomic diversity across multiple generations. An increasing trend in the effective population size of the reintroduced population was consistent with field monitoring data in demonstrating successful re-establishment of the species. This provides a rare empirical example that the adaptive potential of a locally extinct population can be maintained during genetically informed ex-situ conservation breeding and reintroduction into the wild. Strategies to improve biodiversity restoration via ex-situ conservation should include genetic-based captive breeding and longitudinal monitoring of standing genomic variation in reintroduced populations.


Monitoreo Longitudinal de la Diversidad Genómica Neutral y Adaptativa en una Reintroducción Marshall et al. 21-643 Resumen Los programas de restauración a manera de reproducción ex situ combinada con reintroducciones se están volviendo críticos para contrarrestar las declinaciones demográficas y la pérdida de especies. Dichos programas usan cada vez más la gestión genética para mejorar los resultados de conservación. Sin embargo, la falta de monitoreo a largo plazo de los indicadores genéticos posteriores a la reintroducción evita que se realicen evaluaciones de la trayectoria y la persistencia de las poblaciones reintroducidas. Se rescató un pez de talla pequeña (percha pigmea del sur [Nannoperca australis]) previo a su extirpación de los lagos terminales de la Cuenca Murray-Darling en Australia para después reproducirlo en cautiverio con información genética y reintroducirlo. Realizamos monitoreos anuales o bianuales de la abundancia, aptitud y ocupación en vida silvestre durante once años, además de un muestreo genético posterior a la reintroducción. Analizamos los datos genómicos de los grupos originales rescatados, los nacidos en cautiverio y los reintroducidos. Nuestro objetivo era evaluar los efectos genómicos a largo plazo de la reproducción en cautiverio y la reintroducción de esta especie. Esto reveló baja endogamia y el sólido mantenimiento de la diversidad genómica neutral y adaptativa durante varias generaciones. Encontramos una coherencia entre la tendencia creciente en el tamaño de la población efectiva de la población reintroducida y los datos de campo que demostraron el restablecimiento exitoso de la especie. Nuestro estudio proporciona un raro ejemplo empírico de cómo el potencial adaptativo de una población localmente extinta puede mantenerse durante la reproducción de conservación ex situ genéticamente informada y su reintroducción. Las estrategias para mejorar la restauración de la biodiversidad por medio de la conservación ex situ deberían incluir la reproducción en cautiverio basada en la genética y el monitoreo longitudinal de la variación genómica actual de las poblaciones reintroducidas.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Animales , Genómica , Densidad de Población
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