Hybrid Status Research Articles

Identifying hybrids & the genomics of hybridization: Mallards & American black ducks of Eastern North America.

Resolving evolutionary relationships and establishing population structure depends on molecular diagnosability that is often limited for closely related taxa. Here, we use 3,200 ddRAD‐seq loci across 290 mallards, American black ducks, and putative hybrids to establish population structure and estimate hybridization rates. We test between traditional assignment probability and accumulated recombination events based analyses to assign hybrids to generational classes. For hybrid identification, we report the distribution of recombination events complements ADMIXTURE simulation by extending resolution past F4 hybrid status; however, caution against hybrid assignment based on accumulated recombination events due to an inability to resolve F1 hybrids. Nevertheless, both analyses suggest that there are relatively few backcrossed stages before a lineage's hybrid ancestry is lost and the offspring are effectively parental again. We conclude that despite high rates of observed interspecific hybridization between mallards and black ducks in the middle part of the 20th century, our results do not support the predicted hybrid swarm. Conversely, we report that mallard samples genetically assigned to western and non‐western clusters. We indicate that these non‐western mallards likely originated from game‐farm stock, suggesting landscape level gene flow between domestic and wild conspecifics.

Money, power, glory: the linkages between EU conditionality and state capture in the Western Balkans

ABSTRACT The Western Balkan countries are stuck in a hybrid status quo on their way to democracy. Traditional arguments related to cost–benefit calculations, national identity or conflicting objectives fail to explain the observed decoupling between gradual improvements in formal compliance with membership criteria and stagnating, if not declining, democratic performance. We explain the limited impact of the EU’s political conditionality in the Western Balkans with rampant state capture and proceed to unpack how EU conditionality has effectively contributed to the consolidation of such detrimental governance patterns. First, EU pressure for simultaneous economic and political reforms opened opportunities for business actors to build powerful clientelist networks that reach into politics. Second, top-down conditionality has weakened political competition and mechanisms of internal accountability and deliberation. Finally, formal progress towards membership and high-level interactions with EU and member state officials legitimize corrupt elites. A congruence analysis of the Serbian case provides empirical evidence for the hypothesised linkages between EU conditionality and state capture.

The Influence of Inactive Mn4+ Cation on the Redox Behavior of Active Co3+ Cation and O2- anion in Cathode Material.

Co3+/Co4+ redox has been widely utilized in layer structured cathode material for Lithium ion batteries due to its relatively high potential (vs Li+/Li) and good stability during cycling. In comparison, Mn4+ cation is proven to stay inactive for a wide potential range while it activates anionic oxygen redox in Li2MnO3. With introduction of Mn into LiCoO2 system, our experimental results showed that crystal structure had changed into spinel structure with Fd-3m symmetry and the redox behavior of Co3+ and O2- changed dramatically. The redox potential of Co3+/Co4+ increased much from c.a. 3.8V vs Li+/Li in layer structured LiCoO2 to over 5V vs Li+/Li in spinel LiCoMnO4. Meanwhile, the hard X-ray absorption spectroscopy results implied that less oxygen contribution to charge compensation during delithiaion process with Mn substituion. Through careful DFT calculations we revealed that the differences are mainly caused by the inactive dopant Mn elements rather than the transformation of crystal structure. More ionic-like Mn-O bonds induces stronger electron localization in Li-Mn-Co-O system compared with Li-Co-O system and, therefore, changes redox behaviors of Co3+/Co4+ and oxygen participation in charge compensation. Combined with soft X-ray absorption spectroscopy technique, the effects of Mn substitution on electronic hybridization status in Li-Co-O system was verified. Acknowledgement This project was supported by the U.S. Department of Energy, the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies through Advanced Battery Material Research (BMR) program (Battery 500 consortium) under Contract No. DESC0012704

Evolution, Romance and Ritual in Muriel Barbery’s L’Élegance du hérisson (2006)

A parody of existentialist fiction and women’s popular romance, Muriel Barbery’s 2006 diary novel L’Élégance du hérisson seems to promote evolutionary self-understanding as both a great class leveler and a resource for channeling our desire for escape. The novel’s repeated riffs on iconic texts by Jean-Paul Sartre put it in dialogue with previous writers who grappled with meaning in a post-Darwinian world. Yet interspersed or integrated with discussions of humans with, or as animals, are notions borrowed from the newer fields of evolutionary social science and cognitive neuroscience. It is as if the quest for transcendence, once framed as either romantic or philosophical, now called for awareness of our inherited perceptual, cognitive and behavioral equipment. Just what that equipment is, and how it should transform our questing, is what I examine from a biocultural perspective, focusing on the text’s hybrid status as a what may be called a “romance novel of ideas.” I show how Barbery’s novel reinterprets Sartre’smauvaisefoi as a form of cognitive bias from which no one is exempt, and the quest for “transcendence” as symptomatic of a natural human longing for ritualistic experience. That the text may serve an evangelical purpose is a possibility I raise in the conclusion.

Morphological characterization of three natural hybrid orchid taxa, new for Serbia, Montenegro and North Macedonia

During floristic investigations of Serbia, Montenegro and North Macedonia from 2011-2018, orchid specimens from the genus Anacamptis, possible hybrids, with characteristics intermediary to species already described for these countries, were discovered. These specimens, together with all potential parent species, were subjected to morphometric analysis in order to determine their hybrid status and characters that distinguished hybrids from parent taxa. Taxonomic studies have included the processing of quantitative and qualitative characters. A total of 60 characters were analyzed, of which 45 quantitative and 15 qualitative. Analysis of quantitative and qualitative characters included 82 specimens ? 60 parents and 22 hybrids. Statistical analyses included descriptive and discriminate statistics and multivariate analyses. Hybrid specimens in general had intermediate values of measured characters with different degrees of similarity with one of the parent species. On the other hand, they have higher mean values of some floral characters that may have an evolutionary potential. The possible taxonomic importance of hybrid characters is discussed. Results confirmed that the analyzed specimens are natural orchid hybrids (A. ? parvifolia, A. ? timbali and A. ? gennarii) and represent new plant taxa for the flora of investigated countries.

English

English

Distinguishing the victim from the threat: SNP-based methods reveal the extent of introgressive hybridization between wildcats and domestic cats in Scotland and inform future in situ and ex situ management options for species restoration.

The degree of introgressive hybridization between the Scottish wildcat and domestic cat has long been suspected to be advanced. Here, we use a 35‐SNP‐marker test, designed to assess hybridization between wildcat and domestic cat populations in Scotland, to assess a database of 295 wild‐living and captive cat samples, and test the assumptions of the test using 3,097 SNP markers generated independently in a subset of the data using ddRAD. We discovered that despite increased genetic resolution provided by these methods, wild‐living cats in Scotland show a complete genetic continuum or hybrid swarm structure when judged against reference data. The historical population of wildcats, although hybridized, clearly groups at one end of this continuum, as does the captive population of wildcats. The interpretation of pelage scores against nuclear genetic data continues to be problematic. This is probably because of a breakdown in linkage equilibrium between wildcat pelage genes as the two populations have become increasingly mixed, meaning that pelage score or SNP score alone is poor diagnostic predictors of hybrid status. Until better tools become available, both should be used jointly, where possible, when making management decisions about individual cats. We recommend that the conservation community in Scotland must now define clearly what measures are to be used to diagnose a wildcat in the wild in Scotland, if future conservation action is to be effective.

PD-L1 and immune infiltrates are differentially expressed in distinct subgroups of gastric cancer

ABSTRACTThis study investigates the association of PD-L1 expression and immune cell infiltrates and their impact on clinical outcome, in addition to their overlap with microsatellite instability (MSI), HER2 and ATM molecular subgroups of gastric cancer (GC). PD-L1 membrane expression on tumour cells (TC) and infiltrating immune cells (IC), CD3 + T-lymphocytes, CD8+ cytotoxic T-cells, ATM and HER2 were assessed by immunohistochemistry (IHC) in the ACRG (Asian Cancer Research Group) GC cohort (N = 380). EBV status was determined using in situ hybridization and MSI status was performed using PCR and MLH1 IHC. The PD-L1 segment was associated with increased T-cell infiltrates, while the MSI-high segment was enriched for PD-L1, CD3, and CD8. Multivariate analysis confirmed PD-L1 positivity, high CD3 and high CD8 as independent prognostic factors for both disease-free survival and overall survival (all p < 0.05). Patients with MSI-high tumours had better overall survival by both univariate and multivariate analysis. The ATM-low and HER2-high subgroups differed markedly in their immune profile; the ATM-low subgroups enriched for MSI, PD-L1 positivity and CD8 + T-cells, while the HER2 segment was enriched for MSS, with no enrichment for immune markers. Hence, we demonstrate a molecular profiling approach that can divide GC into four molecular subgroups, namely ATM-low, HER2-high, PD-L1 positive and MSI-high with differing levels of immune infiltrates and prognostic significance which may help to stratify patients for response to targeted therapies.

Research on Optimal Control of AC-DC Hybrid Distribution Network

It is hard to optimize power flow and operating status of hybrid AC/DC distribution network with traditional control strategy, so this paper proposed a hierarchical control strategy with different voltage scales. In the first layer, different converter stations maintain stable operation of power system with different control strategy; In the second layer, when power fluctuations of system are large, converter stations change its operation mode to balance voltage fluctuation of DC side; In the third layer, energy optimal dispatch system calculate different converter stations’ control reference to reduce power loss of system. When operation of system change, systems’ stable operation is maintained by switching of control strategy in different layer. The simulation using Matlab/Simulink shows that this control strategy can reduce power loss and system can operate stably even in communication failure.

Testing chestnut hybrids for resistance to Cryphonectria parasitica

Asiatic pathogen Cryphonectria parasitica produced dramatic diebacks of American chestnut (Castanea dentata) and European or sweet chestnut (Castanea sativa) throughout their natural or artificial range, both in forests and orchards. Fungus chemical treatment is a useless (curative) to a less important (preventive) tool. Biological control of Cryphonectria parasitica has various levels of efficiency (from very good to very low), according to compatibility of local strain and fungus mycoviruses. In Romania all the sweet chestnut orchards have been largely destroyed. Till now, searching for natural resistance of European and American chestnut has largely failed. Therefore, chestnut breeding in order to improve resistance to pathogen is imperative both for horticulture and silviculture. In this paper, we tested transferring resistance to C. parasitica from Japanese (Castanea crenata) to European chestnut (C. sativa) in the Carpathian basin, Romania. Open pollinated interspecific hybrids (C. crenata × C. sativa and C. sativa × C. crenata) have been used as tested variants. Sweet chestnuts seedlings of local origin were used as a first control; the second control was a sweet chestnut forest situated at 50 km from the breeding trial. All chestnut material has been under pressure of Cryphonectria parasitica natural infection. We used several characteristics to evaluate the chestnut resistance: presence of fungus (fruitbody, mycelium, and infections), cankers, shoot/branch/stem infections, water sprouts, secondary woody fungus. Complementary, we tested the biological control of C. parasitica. Hybrids' resistance to Cryphonectria parasitica looked very promising, with just a small number of hybrids developing fruit bodies or cankers. On the contrary, first control sweet chestnut collections were severely damaged by the Asian pathogen. Biological control was very efficient both in European chestnut and interspecific hybrids. The untreated forest (second control) was dramatically affected by the fungus. At present, the health status of the chestnut hybrids is very good, showing a very good acclimatization in Carpathian continental climate.

Immobilization of titanium dioxide in mesoporous silicas: Structural design and characterization

The hybridization of titanium dioxide with periodic mesoporous silicas has been investigated so far to construct heterogeneous catalysts. In the present review article, the studies on the complexation of titanium dioxide with periodic mesoporous silicas are summarized from the viewpoints of the preparation and the structural characteristics (the size and the content of titanium dioxide, their location in periodic mesoporous silicas, the porosity of the hybrids) in order to highlight the present status of the titanium dioxide-mesoporous silica hybrids. The structure has been varied depending on the syntheses, which will be correlated to the materials’ performances.

Cutaneous angioimmunoblastic T-cell lymphoma: Epstein-Barr virus positivity and its effects on clinicopathologic features

Epstein-Barr virus (EBV) positivity frequently presents in patients with nodal angioimmunoblastic T-cell lymphoma (AITL). However, the presence of EBV in skin lesions and its clinicopathologic significance have not been evaluated. To analyze the clinical and histopathologic features of cutaneous AITL and evaluate EBV positivity in skin tissue and its effects on clinicopathologic features of AITL. Clinicopathologic variables in patients with cutaneous AITL were analyzed and compared depending on EBV in situ hybridization status in skin lesions by using patients' medical records. Of the 86 patients with AITL, 42 had a cutaneous presentation. In situ hybridizations positive for EBV were noted in 19 of 42 patients with cutaneous AITL. EBV positivity was more common in papular and nodular skin lesions than other cutaneous morphologies, such as nonspecific rash or purpuric patches. An EBV-positive in situ hybridization was associated with a pattern of dense, superficial and deep infiltrates of pleomorphic, large-sized, atypical lymphocytes. EBV positivity in skin lesions was an independent negative prognostic factor in patients with AITL. Retrospective study at a single institution. EBV-positive cutaneous AITL is associated with distinctive clinicopathologic features.

Recurrent hybridisation events between Primula vulgaris, P. veris and P. elatior (Primulaceae, Ericales) challenge the species boundaries: using molecular markers to re‐evaluate morphological identifications

Three Primula species, Primula vulgaris, P. veris and P. elatior, have been objects of fascination for gardeners and botanists over several centuries. The species are able to hybridise, and where they co‐occur, hybrids are commonly found. In Denmark, Møns Klint on the island of Møn and Købelev Skov on Lolland are examples of localities where all three species occur and where the hybrids P. × digenea, the hybrid between P. vulgaris and P. elatior, and P. × polyantha, the hybrid between P. veris and P. vulgaris, can also be found. To investigate relationships between the species and their hybrids, we sampled 168 specimens from 10 geographical locations and subjected them to genetic analysis. The samples were also identified based on morphological traits: primarily inflorescense structure, the size, shape, colour and markings of corolla and leaf basis, leaf blade texture and hairiness. After identifying species‐specific SNPs in the Internal Transcribed Spacer sequence, these were used to resolve species and hybrid boundaries and status through a cleaved amplified polymorphic sequence assay. Polymorphisms in the chloroplast trnL sequence were used as a high‐throughput marker and used to determine the maternal parent of hybrids. Ten simple sequence repeat markers were applied to obtain further insight into the genetic makeup of the accessions using structure and Introgress, providing information of genetic variability within and between populations. Our results indicated that backcrossing of P. × digenea hybrids with parental species has occurred, and that many of the P. × digenea sampled were later‐generation hybrids rather than F1s. Analyses of P. × polyantha specimens show mostly the expected pattern for primary hybrids but indications of P. veris ancestry of a P. vulgaris plant was discovered. Our results further indicate that some of the specimens initially identified as P. elatior include P. vulgaris among their progenitors and thus challenge currently accepted species boundaries.

Silicon-mediated and constitutive resistance to Rhopalosiphum maidis (Hemiptera: Aphididae) in corn hybrids.

The corn leaf aphid, Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae), is an important pest of corn, but no corn genotypes resistant to R. maidis are commercially available. Although the ability of silicon to induce plant resistance against some insects is known, the effect of silicon on R. maidis and in corn hybrids with different levels of constitutive resistance is still unknown. This study sought to determine the constitutive resistance of corn hybrids to R. maidis and silicon resistance induction in hybrids with different degrees of constitutive resistance. Field experiments with natural infestations of aphids were conducted in three locations in Brazil (Patos de Minas, Araguari, and Tupaciguara). Greenhouse trials were also used to evaluate the effect of varietal resistance on aphid population growth and identify resistant and susceptible genotypes. Aphid resistance induced by silicon was determined with resistant and susceptible corn hybrids. In the field, the corn hybrids BM8850, AS1625PRO, and DKB310PRO had the greatest proportion of plants infested by R. maidis in all three localities. The hybrids P30F53H, STATUS VIP, BM9288, DAS2B587HX, DKB175PRO, AS1633PRO, and DKB390PRO2 were the least infested in Patos de Minas and Araguari, and P30F53H was the least infested in Tupaciguara. When antibiosis effects were evaluated by aphid population growth, the hybrids AG7088PRO3 and DKB310PRO2 were susceptible, while P30F53YH was resistant. When natural aphid infestation was evaluated, wherein the effects of antibiosis and non-preference could not be discriminated, soil applications of silicon-induced resistance to R. maidis in both susceptible and constitutively resistant corn hybrids.

Molecular Genetics Unveiled Unknown Family Relationships and Hybrids in an Ex-Situ Colony of African Penguins (Spheniscus demersus).

Genealogical relationships among colony members, inbreeding status, and presence of hybrids are crucial data that can assist zoo curators in captive colony management and decision-making on relocation for reproduction. This study employed molecular markers to study a large colony (n = 56) of African Penguin hosted in an Italian biopark. A panel of 15 STRs (single tandem repeats) was selected, and genotype data were analyzed using COLONY software to determine parentage relationships and compare the existing studbook information to a pedigree built from genetic analyses. The existence of extra-pair mating and the presence of hybrids were investigated: discrepancies in kinship relationships emerged following molecular parentage analysis and 10 unknown genetic relationships were revealed. Infidelity of one member of the pair was observed in 6 cases and extra-pair copulation was assessed by genetic analysis in 2 episodes. One member of the colony was found to be a hybrid (S. demersus × S. humboldti); his progeny, derived by extra-pair copulation, was traced. Three other hidden hybrids were discovered and assessed using the identified candidate private alleles. Overall, our results demonstrate that molecular methods to confirm parentage and analyze relatedness among colony members are a valuable tool to complement studbook-based genetic management of African penguin captive populations. Because a variety of behavioral dynamics (e.g., extra-pair mating) can make observations ineffective in some species and because molecular markers outperform studbook in identifying the presence of hybrids, reliance on studbook information alone is not recommended.

Production of embryo rescued hybrids between the landrace “Friariello” (Capsicum annuum var. annuum) and C. baccatum var. pendulum: phenotypic and cytological characterization

Capsicum baccatum var. pendulum is a valuable source of disease resistance and fruit quality traits that could play an important role in the genetic improvement and safeguard of local varieties of common peppers. However, its use for C. annuum var. annuum breeding has been scarce due to postzygotic incompatibilities. In this work, we obtained seven interspecific hybrids between the Italian landrace ‘Friariello’ of C. annuum var. annuum and C. baccatum var. pendulum through embryo rescue. The F1 hybrids were verified by SSR markers and by in situ hybridization, which confirmed their hybrid status and provided evidence for differences in the repetitive content between the parental genomes. These hybrids were vigorous and, for several morphological traits, were intermediate between their parents. However, they were male sterile. The cytological analysis revealed several abnormalities occurring at various stages of the male meiosis. A number of these anomalies were likely the result of structural differences (e.g. a reciprocal translocation, a paracentric inversion) between the two genomes. Due to hybrid pollen sterility, backcross progenies (BC1) were obtained when hybrids were used as female parents. A partial restoration of the fertility in BC1 makes promising the exploitation of this material in breeding programs.

Theater reminiscences: the politics of memory after the expulsion of the Moriscos

ABSTRACTThis paper explores how theater reminiscences helped Moriscos to strengthen their sense of community in North Africa after their expulsion from Spain (1609–1614). Moriscos in exile remembered early modern Spanish theater so as to deal with the difficult circumstances of losing their land but also to highlight their sense of identity as distinct from that of other Muslims outside the Iberian Peninsula, who did not have a strong theater tradition. By tracing references to theater in two manuscripts written in Tunisia, El manuscrito morisco 9653 de la Biblioteca Nacional de Madrid (Mami 2002. El manuscrito morisco 9653 de la Biblioteca Nacional de Madrid. Madrid: Fundación Ramón Menéndez Pidal.) and Tratado de los dos caminos por un morisco refugiado en Túnez (Galmés de Fuentes 2005. Tratado de los dos caminos por un morisco refugiado en Túnez. Madrid: Universidad Complutense de Madrid, Instituto Universitario Seminario Menéndez Pidal.), through the lens of memory studies, instances of remembering are viewed as a strategy for Moriscos to celebrate their past but also to recognize their hybrid status in their new lands. I use Jan Assman’s definition of communicative memory as the theoretical framework of this essay and take into consideration the element of space in classical treatises on memory.

Revealing genetic hybridization and DNA recombination of Fasciola hepatica and Fasciola gigantica in nuclear introns of the hybrid Fasciola flukes

Fasciola hepatica and F. gigantica are ruminant liver flukes that are found worldwide. They can occur sympatrically and hybridize, consequently producing an intermediate form (Fasciola sp.), especially in Africa and Asia. The bridge intron (TkBridgeInt) and intron 4 of domain 2 (TkD2Int4) of the taurocyamine kinase gene were cloned and sequenced from 14 F. hepatica, 18 F. gigantica, and 12 Fasciola sp. These intron regions could be used to differentiate F. hepatica from F. gigantica and revealed genetic hybridization and DNA recombination between F. hepatica and F. gigantica in Fasciola sp. from Japan and Bangladesh. Two specimens of F. hepatica from Ecuador revealed cryptic diversity. A combination of three haplotypes observed in a Fasciola sp. specimen from Japan suggested triploidy. Thus, the intron region of the taurocyamine kinase gene is a potential marker for detecting the hybrid status of the Fasciola flukes.

Effect of hybridization with genome exclusion on extinction risk.

Human-induced habitat changes may lead to the breakdown of reproductive barriers between distantly related species. This phenomenon may result in fertile first-generation hybrids (F1 ) that exclude the genome of one parental species during gametogenesis, thus disabling introgression. The species extinction risk associated with hybridization with genome exclusion is largely underappreciated because the phenomenon produces only F1 hybrid phenotype, leading to the misconception that hybrids are sterile and potentially of minor conservation concern. We used a simulation model that integrates the main genetic, demographic, and ecological processes to examine the dynamics of hybridization with genome exclusion. We showed that this mode of hybridization may lead to extremely rapid extinction when the process of genome exclusion is unbalanced between the interbreeding species and when the hybridization rate is not negligible. The coexistence of parental species was possible in some cases of asymmetrical genome exclusion, but show this equilibrium was highly vulnerable to environmental variation. Expanding the exclusive habitat of the species at risk allowed its persistence. Our results highlight the extent of possible extinction risk due to hybridization with genome exclusion and suggest habitat management as a promising conservation strategy. In anticipation of serious threats to biodiversity due to hybridization with genome exclusion, we recommend a detailed assessment of the reproductive status of hybrids in conservation programs. We suggest such assessments include the inspection of genetic content in hybrid gametes.

Pest categorisation of Apiosporinamorbosa.

The Panel on Plant Health performed a pest categorisation of the fungus Apiosporina morbosa, the causal agent of black knot, for the EU. The identity of the pest is well established and reliable methods exist for its detection/identification. The pest is listed in Annex IIAI of Directive 2000/29/EC and is not known to occur in the EU. Apiosporina morbosa is present in Alaska, Canada, Mexico and the continental states of the USA. The major hosts of A. morbosa are Prunus domestica and Prunus cerasus; the host status of other Prunus species and hybrids is uncertain because of contradictory reports or lack of information. The pest could potentially enter the EU on host plants for planting and plant parts originating in infested third countries. Wood of Prunus spp. is also a pathway of entry, but of minor importance. The current pest distribution and climate matching suggest that the pest could establish and spread in the EU wherever the hosts are grown. In the infested areas, the pest causes girdling of twigs and occasionally of larger branches, whereas trees with multiple infections loose vigour, bloom poorly, and become unproductive, stunted and susceptible to winter injury and infection by other pathogens. The presence of black knots makes trees unsuitable for timber production. It is expected that the pest introduction and spread in the EU would impact host production. Uncertainty exists on whether the agricultural practices and chemical control methods applied in the EU could prevent the establishment and spread of A. morbosa. A. morbosa meets all the criteria assessed by EFSA for consideration as potential Union quarantine pest. As the pest is not known to occur in the EU, this criterion to consider it as Union regulated non‐quarantine pest is not met.