The population genetics of the fundamental cytotype-shift in invasive Centaurea stoebe s.l.: genetic diversity, genetic differentiation and small-scale genetic structure differ between cytotypes but not between ranges

Polyploids are overrepresented in invasive species. Yet, the role of genetic diversity and drift in colonization success of polyploids remains unclear. Here, we investigate genetic diversity, genetic differentiation and small-scale genetic structure in our model system, the three geo-cytotypes of Centaurea stoebe: monocarpic diploids and polycarpic (allo)tetraploids coexist in the native range (Eurasia), but only tetraploids are reported from the invasive range (North America). For each geo-cytotype, we investigated 18–20 populations varying in size and habitat type (natural vs. ruderal). Population genetic analyses were conducted at eight microsatellite loci. Compared to diploids, tetraploids revealed higher genetic diversity and lower genetic differentiation, whereas both were comparable in tetraploids between both ranges. Within spatial distances of a few meters, diploid individuals were more strongly related to one another than tetraploids. In addition, expected heterozygosity in diploids increased with population size and was higher in natural than in ruderal habitats. However, neither relationship was found for tetraploids. The higher genetic diversity of tetraploid C. stoebe may have enhanced its colonization abilities, if genetic diversity is correlated with fitness and adaptive capabilities. Furthermore, the inheritance of a duplicated chromosome set as well as longevity and frequent gene flow reduces drift in tetraploids. This counteracts genetic depletion during initial introductions and in subsequent phases of small or fluctuating population sizes in ruderal habitats. Our findings advocate the importance of studying colonization genetic processes to gain a more mechanistic understanding of the role of polyploidy in invasion dynamic

Process data of allogeneic ex vivo-expanded ABCB5+ mesenchymal stromal cells for human use: Off-the-shelf GMP-manufactured donor-independent ATMP

© 2020, The Author(s). Background: Human dermal mesenchymal stromal cells (MSCs) expressing the ATP-binding cassette (ABC) efflux transporter ABCB5 represent an easily accessible MSC population that, based on preclinical and first-in-human data, holds significant promise to treat a broad spectrum of conditions associated not only with skin-related but also systemic inflammatory and/or degenerative processes. Methods: We have developed a validated Good Manufacturing Practice-compliant expansion and manufacturing process by which ABCB5+ MSCs derived from surgical discard skin tissues are processed to an advanced-therapy medicinal product (ATMP) for clinical use. Enrichment for ABCB5+ MSCs is achieved in a three-step process involving plastic adherence selection, expansion in a highly efficient MSC-selecting medium, and immunomagnetic isolation of the ABCB5+ cells from the mixed culture. Results: Product Quality Review data covering 324 cell expansions, 728 ABCB5+ MSC isolations, 66 ABCB5+ MSC batches, and 85 final drug products reveal high process robustness and reproducible, reliable quality of the manufactured cell therapy product. Conclusion: We have successfully established an expansion and manufacturing process that enables the generation of homogenous ABCB5+ MSC populations of proven biological activity manufactured as a standardized, donor-independent, highly pure, and highly functional off-the-shelf available ATMP, which is currently tested in multiple clinical trials

Polyploidy can increase colonization ability – Lessons from diploid and tetraploid spotted knapweed -Centaurea stoebe

Polyploid plants show a higher probability to become invasive than diploids, however, the underlying mechanisms are not fully understood. Early-acting invasion filters may offer high explanatory power in understanding such biogeographical patterns, because they can inherently determine whether founder populations fail or succeed in colonizing a novel range. Christoph’s talk aims to contri-bute to a more complete understanding of the processes that shape the colonization success of polyploids. His model organism, the polyploid complex Centaurea stoebe s.l., comprises three so-called geo-cytotypes: monocarpic diploids are more frequent than poly-carpic (allo)tetraploids in the native range (Eurasia), whereas only tetraploids are reported from the invasive range (North America)

Data from: Geographical parthenogenesis and population genetic structure in the alpine species Ranunculus kuepferi (Ranunculaceae)

Geographical parthenogenesis describes the enigmatic phenomenon that asexual organisms have larger distribution areas than their sexual relatives, especially in previously glaciated areas. Classical models suggest temporary advantages to asexuality in colonization scenarios because of uniparental reproduction and clonality. We analyzed population genetic structure and self-fertility of the plant species Ranunculus kuepferi on 59 populations from the whole distribution area (European Alps, Apennines and Corsica). Amplified fragment length polymorphisms (AFLPs) and five microsatellite loci revealed individual genotypes for all populations and mostly insignificant differences between diploid sexuals and tetraploid apomicts in all measures of genetic diversity. Low frequencies of private AFLP fragments/simple sequence repeat alleles, and character incompatibility analyses suggest that facultative recombination explains best the unexpectedly high genotypic diversity of apomicts. STRUCTURE analyses using AFLPs revealed a higher number of partitions and a stronger geographical subdivision for diploids than for tetraploids, which contradicts expectations of standard gene flow models, but indicates a reduction of genetic structure in asexuals. Apomictic populations exhibited high admixture near the sexual area, but appeared rather uniform in remote areas. Bagging experiments and analyses of pollen tube growth confirmed self-fertility for pollen-dependent apomicts, but self-sterility for diploid sexuals. Facultative apomixis combines advantages of both modes of reproduction: uniparental reproduction allows for rapid colonization of remote areas, whereas facultative sexuality and polyploidy maintains genetic diversity within apomictic populations. The density dependence of outcrossing limits range expansions of sexual populations

Data from: Invasion success in polyploids: the role of inbreeding in the contrasting colonization abilities of diploid versus tetraploid populations of Centaurea stoebe s.l

As a consequence of founder effects, inbreeding can hamper colonization success: First, in species with self-incompatibility controlled by an S-locus, inbreeding may decrease cross-compatibility, mainly due to the sharing of identical S-alleles between closely related mating partners. Secondly, inbreeding can reduce fitness of inbred relative to outbred offspring (i.e. inbreeding depression). Polyploids often show reduced inbreeding depression compared to diploids, which may contribute to the overrepresentation of polyploids among invasive species. This is the first study that tests how the effects of inbreeding differ between geocytotypes (i.e. ploidy levels within a given range). Our model organism, Centaurea stoebe, is strictly self-incompatible and comprises three geocytotypes: diploids are more frequent than tetraploids in the native range, while only tetraploids occur in the invasive range. We conducted a breeding experiment (sib-mating vs. outcrossing) with 14 native diploid, 13 native tetraploid and 15 invasive tetraploid populations. We recorded cross-compatibility and estimated a cumulative index for offspring fitness. Since frequent inbreeding can result in purging of genetic load responsible for inbreeding depression, our analyses included a metric for within-population relatedness, based on eight microsatellite markers, to assess the effect of purging. Inbreeding was found to reduce cross-compatibility, which was similarly pronounced in diploids and tetraploids. It also caused inbreeding depression in cumulative fitness, which was significant in diploids but not in tetraploids. No evidence of purging was observed as inbred fitness was not affected by within-population relatedness. Synthesis. Our results provide new insights into the contrasting invasion success of the cytotypes of C. stoebe. As the effects of cross-compatibility and purging were comparable between cytotypes, both processes can be ruled out to affect the colonization success of diploids versus tetraploids. Our findings are consistent with the hypothesis that polyploidy increases the masking of recessive mutations, which maintains high fitness in inbred tetraploids and may thus facilitate colonization of new ranges. We highlight that reduced inbreeding depression may add to previously acknowledged advantages of polyploids in range expansions, a mechanism that may hitherto have been underestimated due to a lack of data on variation in inbreeding depression across geocytotypes

lineages_data

Inbred and outbred lineages from which fitness components were obtained. Arabic numerals refer to population numbers. Numbers of populations correspond to those in Table S1

Biogeographic differences in the allelopathy of leaf surface extracts of an invasive weed

Allelopathy, the release of chemicals byplants that inhibit the germination and growth ofcompeting species, can be an important trait forinvasive success. However, little is known aboutpotential biogeographical differences in allelopathydue to divergent regional eco-evolutionary histories.To test this, we examined the allelochemical potentialof the highly invasive species Centaurea solstitialisfrom six world regions including native (Spain,Turkey) and non-native ranges (Argentina, Chile, California and Australia). Seeds from several populationsin each region were collected and grown undercommon garden conditions. Allelopathic potential andchemical composition of three leaf extract concentrationsof C. solstitialis from each region: 0.25%, 0.5%0.75% (w/v-1) were assessed on the phytometerLactuca sativa. The main allelochemicals present inthe leaf-surface extract were sesquiterpene lactonesthat varied in major constitutive compounds acrossregions. These leaf extracts had strong inhibitoryeffects on L. sativa seed germination and net growth.Summed across regions, the 0.25% concentrationsuppressed germination by 72% and radicle elongationby 66%, relative to the controls. At the 0.5% concentration, no seeds germinated when exposed toextracts from the non-native ranges of Argentina andChile, whereas germination and radicle growth werereduced by 98% and 89%, respectively, in theremaining regions, relative to controls. Germinationand seedling growth were completely inhibited at the0.75% concentration extract for all regions. Some nonnativeregions were characterized by relatively lowerconcentrations of allelochemicals, suggesting thatthere is biogeographical variation in allelopathicexpression. These findings imply that rapid selectionon the biochemical signatures of an exotic invasiveplant species can be highly region-specific across theworld.Fil: Irimia, Ramona E.. Universidad de Coimbra; PortugalFil: Lopes, Susana M. M.. Universidad de Coimbra; PortugalFil: Sotes, Gastón. Universidad de Tarapaca.; Chile. Universidad de Chile; ChileFil: Cavieres, Lohengrin A.. Universidad de Chile; Chile. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanografía; ChileFil: Eren, Ozkan. Adnan Menderes Universitesi; TurquíaFil: Lortie, Christopher J.. York University; CanadáFil: French, Kristine. University Of Wollongong. School Of Earth And Enviromental Sciences; AustraliaFil: Hierro, Jose Luis. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Confluencia. Instituto de Ciencias de la Tierra y Ambientales de la Pampa. Grupo Vinculado Fundacion Centro de Salud E Investigaciones Medicas | Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de la Pampa. Grupo Vinculado Fundacion Centro de Salud E Investigaciones Medicas.; ArgentinaFil: Rosche, Christoph. University of Montana; Estados Unidos. Martin Luther University Halle Wittenberg; AlemaniaFil: Callaway, Ragan M.. University of Montana; Estados UnidosFil: Pinho e Melo, Teresa M. V. D.. Universidad de Coimbra; PortugalFil: Montesinos, Daniel. Universidad de Coimbra; Portugal. James Cook University; Australi

data_SPAGeDi_format

The microsatellite data is presented in a format that is accepted by the software SPAGeDi. You may use SPAGeDi to re-run the analyses and/or to convert the data into other formats

Climate outweighs native vs. nonnative range-effects for genetics and common garden performance of a cosmopolitan weed

Rosche C, Hensen I, Schaar A, et al. Climate outweighs native vs. nonnative range-effects for genetics and common garden performance of a cosmopolitan weed. Ecological Monographs . 2019;89(4): UNSP e01386.Comparing genetic diversity, genetic differentiation, and performance between native and nonnative populations has advanced our knowledge of contemporary evolution and its ecological consequences. However, such between-range comparisons can be complicated by high among-population variation within native and nonnative ranges. For example, native vs. nonnative comparisons between small and non-representative subsets of populations for species with very large distributions have the potential to mislead because they may not sufficiently account for within-range adaptation to climatic conditions, and demographic history that may lead to non-adaptive evolution. We used the cosmopolitan weed Conyza canadensis to study the interplay of adaptive and demographic processes across, to our knowledge, the broadest climatic gradient yet investigated in this context. To examine the distribution of genetic diversity, we genotyped 26 native and 26 nonnative populations at 12 microsatellite loci. Furthermore, we recorded performance traits for 12 native and 13 nonnative populations in the field and in the common garden. To analyze how performance was related to range and/or climate, we fit pedigree mixed-effects models. These models weighed the population random effect for co-ancestry to account for the influence of demographic history on phenotypic among-population differentiation. Genetic diversity was very low, selfing rates were very high, and both were comparable between native and nonnative ranges. Nonnative populations out-performed native populations in the field. However, our most salient result was that both neutral genetic differentiation and common garden performance were far more correlated with the climatic conditions from which populations originated than native vs. nonnative range affiliation. Including co-ancestry of our populations in our models greatly increased explained variance and our ability to detect significant main effects for among-population variation in performance. High propagule pressure and high selfing rates, in concert with the ability to adapt rapidly to climatic gradients, may have facilitated the global success of this weed. Neither native nor nonnative populations were homogeneous groups but responded comparably to similar environments in each range. We suggest that studies of contemporary evolution should consider widely distributed and genotyped populations to disentangle native vs. nonnative range effects from varying adaptive processes within ranges and from potentially confounding effects of demographic history