Hybridization Patterns Research Articles

Historical and ongoing hybridisation in Southern South American grassland species.

Natural hybridisation in plants can impact genetic and morphological diversity, including the emergence of better-adapted new populations and the potential extinction of some lineages involved in this intricate process. Under progressive global warming, species often need to migrate to newly suitable areas, which may be an additional challenge for species with low dispersal ability. Throughout the search for new environments, previously allopatric lineages can come into secondary contact and eventually hybridise if reproductive isolation is incomplete. Here, we focused on two taxa representing the natural herbaceous component of southern South American lowland grasslands. We aimed to evaluate the impact of contact zones and potential hybridisation on the evolutionary relationships and population dynamics. We used single nucleotide polymorphisms and morphological data of multiple individuals from allopatric and contact zones between taxa to shed light on hybridisation patterns and demographic scenarios. Our results indicated that the contact zones impact taxa's genetic and morphological diversity, and each contact zone had different patterns of genetic diversity and morphology, constituting stable populations that potentially reflect hybridisation events occurring at distinct evolutionary times.

Asymmetrical hybridization and environmental factors influence the spatial genetic structure of a killifish hybrid zone.

Hybridization offers insight into speciation and the forces that maintain barriers to reproduction, and hybrid zones provide excellent opportunities to test how environment shapes barriers to reproduction and hybrid fitness. A hybrid zone between the killifish, Fundulus heteroclitus and F. grandis, had been identified in northeastern Florida, although the spatial structure and parameters that affect the distribution of the two species remain unknown. The present study aimed to determine the fine-scale spatial genetic patterns of the hybrid zone to test the hypothesis that species ranges are influenced by changes in dominant vegetation, and to determine how differences in reproductive barriers between the two species influence the observed patterns. The area of overlap between the two species spanned ~37 km and showed a mosaic pattern of hybridization, suggesting the spatial structure of the hybrid zone is largely influenced by the environment. Environmental association analysis, however, suggested that while dominant vegetation had a significant influence on the spatial structure of the hybrid zone, a combination of environmental factors was driving the observed patterns. Hybridization tended to be rare at sites where F. heteroclitus was the more abundant species, suggesting that differences in preference for conspecifics can lead to differences in rates of introgression into parental taxa and likely result in a range-shift as opposed to adaptation in the face of climate change.

Unravelling intermediate migration patterns in gull hybrids: insights from ring re-encounters

Hybridization is a common phenomenon in birds, particularly between closely related species, when reproductive isolation mechanisms are insufficiently developed. Hybrids differ from the parental species in genetic, morphological, and behavioural traits. However, the migration patterns of hybrids have been scarcely studied. Examining hybrid migration behaviour is essential as it may reveal their role as a “gene bridge” between species and enhance our understanding of speciation mechanisms and the genetics of migration. Most research focuses on tracking the migration of long-distance migrants, but the effect of hybridization on migration is poorly understood also in short-distance migrants. The study aimed to verify whether the migratory movements of interspecific hybrids between the Herring (Larus argentatus) and the Caspian Gull (L. cachinnans) are intermediate, as predicted by the genetic basis of migration. Migration patterns, based on distance and direction, were determined from re-encounter data of individuals ringed in Poland, for over 20 years (2002–2023). These included both allopatric (parental species) and sympatric (both parental species and hybrids) populations. The results indicated that large gull hybrids exhibit an intermediate migration patterns, similarly to other hybridizing species. Unlike many cases where intermediacy may select against hybrids, the absence of significant environmental barriers along gulls’ migration routes and their wide wintering range likely mitigates selective pressures. This finding underscores the need for further investigation into the ecological implications of hybrid migration patterns. By using bird re-encounter data, we demonstrated that it provides a sufficient basis for analysing migration patterns and detecting intermediacy, even in within-continental and short-distance migrants.

Prezygotic barriers effectively limit hybridization in a rapid evolutionary radiation.

Hybridization is increasingly recognized as an important evolutionary process across the tree of life. In many clades, phylogenomic approaches have permitted unparalleled insight into the extent and frequency of hybridization. However, we continue to lack a deep understanding of the factors that limit and shape patterns of hybridization, especially in evolutionary radiations. In this study, we characterized patterns of introgression across Costus (Costaceae), a young evolutionary radiation of tropical understory plants that maintain widespread interfertility despite exhibiting strong prezygotic reproductive isolation. We analyzed a phylogenomic dataset of 756 genes from 54 Costus species using multiple complementary approaches - D-statistics, gene-tree-based tests, and phylogenetic network analyses - to detect and characterize introgression events throughout the evolutionary history of the radiation. Our results identified a moderate number of introgression events, including a particularly ancient, well-supported event spanning one of the deepest divergences in the clade. Most introgression events occurred between taxa or ancestral lineages that shared the same pollination syndrome (bee-pollinated or hummingbird-pollinated). These findings suggest that prezygotic barriers, including pollinator specialization, have been key to the balance between introgression and reproductive isolation in Costus.

Unifying framework explaining how parental regulatory divergence can drive gene expression in hybrids and allopolyploids.

Hybridization and polyploidy are powerful evolutionary forces, inducing a range of phenotypic outcomes, including non-additive expression, subgenome dominance, deviations ingenomic dosage, and transcriptome downsizing. The reasons for these patterns and whether they are universal adaptive responses to genome merging and doubling remain debated. To address this, we develop a thermodynamic model of gene expression based ontranscription factor (TF)-promoter binding. Applied to hybridization between species with divergent gene expression levels, cell volumes, or euchromatic ratios, this model distinguishes the effects of hybridization from those of polyploidy. Our results align with empirical observations, suggesting that gene regulation patterns in hybrids and polyploids often stem from the constrained interplay betweeninherited diverged regulatory networks rather than from subsequent adaptive evolution. In addition, occurrence ofcertain phenotypic traits depend on specific assumptions about promoter-TF coevolution and their distribution within the hybrid's nucleoplasm, offering new research avenues to understand the underlying mechanisms. In summary, our model explains how the legacy of divergent species directly influences the phenotypic traits of hybrids and allopolyploids.

Experimental study of subcooled flow boiling in microchannel heat sinks integrated with different embedded pin fin arrays microstructures

The optimized microchannel heat sinks could enhance flow boiling for effectively tackling the electronics cooling. The flow boiling experiment for three microchannel heat sinks integrated with different layouts of entrenched pin fins is conducted at flow rate of 273.6–456 kg/(m2.s) and inlet subcooling of 35∼50 K. The overall/local heat transfer features, pressure drop and boiling mechanism are studied. The hybrid pattern presents earliest initial boiling and lower superheat than the microchannel heat sink with uniform pin fins arrangement at moderate and large flow rates. The trend of overall and local HTC (heat transfer coefficient) is similar, which occurs peak at onset nucleation boiling, and then decreasing with increasing heat flux. At the largest flow rate, the hybrid pattern exhibits 2.7–3.5 times peak HTC promotion than other patterns. As for lowest flow rate, the hybrid pattern does not manifest remarkably superior performance due to downstream vapor cores clogging effect. The hybrid pattern shows largest pressure drop, and the smaller inlet subcooling manifests inferior heat transfer and resistance performance. The comprehensive performance factor (CPF) is proposed, and the pattern with uniform small-sized pin fins shows optimal CPF especially for low flow rate, which is considerable compared with the reference heat sink structures until high heat flux. This study may provide some insight into the design of microchannel for flow boiling heat dissipation.

Assessment of mechanical and thermal properties of hybrid co-woven biofiber polymer composites

The recent research explores the hybridizing effect of inter and intra woven natural engineering fibers in epoxy composites. The inter and intra woven brown flax (Fb), white flax (Fw), and jute (J) fabrics have been comingled with short coir fibers (SCF). The composites are successfully made using the hand layup procedure, and the successive arrangement of fabrics is based on the tensile characteristics of inter and intra-woven fabrics. The physical, thermal, and mechanical characteristics of composites are experimentally studied. The C1 composite having (Fb+Fw)/Fw/J/J/Fw/(Fb+Fw) fabric sequence without filler demonstrated highest tensile strength of 30.15 MPa, elastic modulus of 2164.59 MPa, flexural strength of 66.46 MPa, and flexural modulus of 3900.74 MPa. However, the C3 composite containing SCF filler, having a similar fabric sequence as that of C1 demonstrated highest impact strength of 116.52 KJ/m2. Thermogravimetric analysis (TGA) revealed that the composite C3 exhibited better thermal stability than other hybrid patterns. Fourier transform infrared (FTIR) spectroscopy study confirmed the interaction of hydrogen bonds with different polymers, matrices, and fillers. Further, microstructural and fractography analysis have been done to analyze the surface phenomena of the composites and mechanical failure analysis.

Highly divergent satellitomes of two barley species of agronomic importance, Hordeum chilense and H. vulgare

In this paper, we have performed an in-depth study of the complete set of the satellite DNA (satDNA) families (i.e. the satellitomes) in the genome of two barley species of agronomic value in a breeding framework, H. chilense (H1 and H7 accessions) and H. vulgare (H106 accession), which can be useful tools for studying chromosome associations during meiosis. The study has led to the analysis of a total of 18 satDNA families in H. vulgare, 25 satDNA families in H. chilense (accession H1) and 27 satDNA families in H. chilense (accession H7) that constitute 46 different satDNA families forming 36 homology groups. Our study highlights different important contributions of evolutionary and applied interests. Thus, both barley species show very divergent satDNA profiles, which could be partly explained by the differential effects of domestication versus wildlife. Divergence derives from the differential amplification of different common ancestral satellites and the emergence of new satellites in H. chilense, usually from pre-existing ones but also random sequences. There are also differences between the two H. chilense accessions, which support genetically distinct groups. The fluorescence in situ hybridization (FISH) patterns of some satDNAs yield distinctive genetic markers for the identification of specific H. chilense or H. vulgare chromosomes. Some of the satellites have peculiar structures or are related to transposable elements which provide information about their origin and expansion. Among these, we discuss the existence of different (peri)centromeric satellites that supply this region with some plasticity important for centromere evolution. These peri(centromeric) satDNAs and the set of subtelomeric satDNAs (a total of 38 different families) are analyzed in the framework of breeding as the high diversity found in the subtelomeric regions might support their putative implication in chromosome recognition and pairing during meiosis, a key point in the production of addition/substitution lines and hybrids.

Clinicopathologic Features and Digital Imaging Analysis of HER2 Protein in Breast Carcinomas With Different HER2 Fluorescence in Situ Hybridization Patterns

BackgroundHER2-targeted therapies have significantly improved outcomes for patients with HER2-positive breast cancer (BC), which represents 15% to 20% of all BC cases. HER2 status is assessed via immunohistochemistry (IHC) and/or in situ hybridization (ISH), dividing BCs into five groups (G1-G5). Patients and methodsIn a study of 2,702 primary BC cases, comprising 12.7% G1, 0.2% G2, 2.8% G3, 8.5% G4, and 75.9% G5, we analyzed clinicopathologic features and HER2 protein expression digitally for each ISH group. ResultsNotably, G5 cases had a higher proportion of lobular carcinoma (13.9%) compared to other groups. G3 cases showed the highest percentage of grade 3 tumors (56.9%), while G5 cases had the lowest (21.4%). Additionally, G5 cases had the highest rate of estrogen receptor (ER) positivity (84.6%), while G1-HC (high copy number) cases had the lowest (70.4%). Most G1-HC cases were HER2 IHC 3+ (76.1%), while most G5 cases were IHC 0/1+ (75.7%). IHC 2+ was most common in G1-LC (low copy number) and G3 cases (83.8% and 90.7%, respectively), with G4 cases predominantly IHC 2+ (56.3%) and IHC 1+ (30.1%). Discordant HER2 IHC and ISH results were observed in 12 cases (0.4%), including 7 G1-HC (2.3%), 4 G1-LC (10.8%), and 1 G5 case (0.1%). Digital quantification of HER2 IHC levels in all groups except G5 revealed that G1-HC tumors had the highest HER2 protein expression, followed by G3, with G4 showing the lowest. ConclusionThese findings offer valuable insights into the clinicopathologic characteristics and future management for different HER2 ISH groups.

Surviving the extinction vortex? Discovering remnant stands of Senecio hercynicus (Compositae, Senecioneae) evading genetic swamping by its congener S. ovatus in the Bavarian and Bohemian Forest region

Genetic swamping by introgressive hybridisation threatens diversity, caused by climate warming particularly in mountainous regions worldwide. Recent studies resulted in a threatening perspective for Senecio hercynicus in the Bavarian Forest due to genetic swamping by introgressive hybridisation with its cogener S. ovatus. To examine the situation more closely, the distribution and hybridization of S. hercynicus and S. ovatus in high elevation regions of the Bavarian and Bohemian Forest was analyzed by restriction enzyme digestion of nrDNA ITS1 (PCR-RFLP; PCR restriction fragment length polymorphism). For a total of 706 samples from 94 different sample localities a hybrid index was inferred from the fragment band intensities after PCR-RFLP digestion. Boxplot diagrams of the hybrid indices show a tendency of western populations towards S. ovatus genotypes and for populations to the east towards S. hercynicus genotypes. When the hybrid index data was subjected to a regression analysis with nine factors (five habitat patterns inferred during sampling and four bioclimatic variables), only geographical longitude and latitude seemed to describe the observed distribution of S. hercynicus and S. ovatus significantly, arguing for the distribution and hybridisation patterns being shaped rather due to historical than to eco-climatological determinants. While a broad zone of hybridisation between the two species in the Bavarian and Bohemian Forest region was inferred, our study demonstrates that purebred S. hercynicus still exists and remnant stands of this species should be the target of species conservation measures.

Clinical Outcomes and Efficacy of Human Epidermal Growth Factor Receptor 2–Targeted Therapy in Breast Cancer With Uncommon In Situ Hybridization Patterns or Discordant Immunohistochemistry

Clinical Outcomes and Efficacy of Human Epidermal Growth Factor Receptor 2–Targeted Therapy in Breast Cancer With Uncommon In Situ Hybridization Patterns or Discordant Immunohistochemistry

Hybrid Patterns and Solitonic Frequency Combs in Non-Hermitian Kerr Cavities.

We unveil a new scenario for the formation of dissipative localized structures in nonlinear systems. Commonly, the formation of such structures arises from the connection of a homogeneous steady state with either another homogeneous solution or a pattern. Both scenarios, typically found in cavities with normal and anomalous dispersion, respectively, exhibit unique fingerprints and particular features that characterize their behavior. However, we show that the introduction of a periodic non-Hermitian modulation in Kerr cavities hybridizes the two established soliton formation mechanisms, embodying the particular fingerprints of both. In the resulting novel scenario, the stationary states acquire a dual behavior, playing the role that was unambiguously attributed to either homogeneous states or patterns. These fundamental findings have profound practical implications for frequency comb generation, introducing unprecedented reversible mechanisms for real-time manipulation.

The “d-p orbital hybridization”-guided design of novel two-dimensional MOFs with high anchoring and catalytic capacities in Lithium − Sulfur batteries

The energy system of lithium-sulfur batteries is quite promising, however, lithium-sulfur batteries still suffer from considerable problems, such as the abominable shuttle effect of polysulfides (LiPSs), the low conductivity of the solid-phase products, the slow redox kinetics during charging and discharging, and the volume expansion. Herein, the hybridization pattern between the d-orbitals of various transition metal atoms and the p-orbitals of sulfides is revealed grounded in the theory of density function, which explains the high adsorption strength of two-dimensional metal–organic frameworks (MOFs) with LiPSs and accelerates the screening of high-performance anchoring and catalytic materials. The results elucidate that the coordinated transition metal–organic frameworks (Mo-NH MOF) monolayers increase the capacity of LiPSs to anchor by forming more π-bonds from the hybridization of the S p orbitals and Mo d orbitals. Notably, Mo-NH MOF exhibits bifunctional catalytic activity for sulfur reduction as well as Li2S decomposition reactions during charging and discharging, which improves the conversion efficiency of redox reactions. As a result, new MOF materials featuring unique active centers and the potential mechanism by which the active centers modulate the performance of the substrate materials are revealed, and this finding may accelerate the development of high-performance Li-S batteries.

Trait Variation and Spatiotemporal Dynamics across Avian Secondary Contact Zones.

A secondary contact zone (SCZ) is an area where incipient species or divergent populations may meet, mate, and hybridize. Due to the diverse patterns of interspecific hybridization, SCZs function as field labs for illuminating the on-going evolutionary processes of speciation and the establishment of reproductive isolation. Interspecific hybridization is widely present in avian populations, making them an ideal system for SCZ studies. This review exhaustively summarizes the variations in unique traits within avian SCZs (vocalization, plumage, beak, and migratory traits) and the various movement patterns of SCZs observed in previous publications. It also highlights several potential future research directions in the genomic era, such as the relationship between phenotypic and genomic differentiation in SCZs, the genomic basis of trait differentiation, SCZs shared by multiple species, and accurate predictive models for forecasting future movements under climate change and human disturbances. This review aims to provide a more comprehensive understanding of speciation processes and offers a theoretical foundation for species conservation.

The role of deep hybridization in fern speciation: Examples from the Thelypteridaceae.

Hybridization is recognized as an important mechanism in fern speciation, with many allopolyploids known among congeners, as well as evidence of ancient genome duplications. Several contemporary instances of deep (intergeneric) hybridization have been noted, invariably resulting in sterile progeny. We chose the christelloid lineage of the family Thelypteridaceae, recognized for its high frequency of both intra- and intergeneric hybrids, to investigate recent hybrid speciation between deeply diverged lineages. We also seek to understand the ecological and evolutionary outcomes of resulting lineages across the landscape. By phasing captured reads within a phylogenomic data set of GoFlag 408 nuclear loci using HybPhaser, we investigated candidate hybrids to identify parental lineages. We estimated divergence ages by inferring a dated phylogeny using fossil calibrations with treePL. We investigated ecological niche conservatism between one confirmed intergeneric allotetraploid and its diploid progenitors using the centroid, overlap, unfilling, and expansion (COUE) framework. We provide evidence for at least six instances of intergeneric hybrid speciation within the christelloid clade and estimate up to 45 million years of divergence between progenitors. The niche quantification analysis showed moderate niche overlap between an allopolyploid species and its progenitors, with significant divergence from the niche of one progenitor and conservatism to the other. The examples provided here highlight the overlooked role that allopolyploidization following intergeneric hybridization may play in fern diversification and range and niche expansions. Applying this approach to other fern taxa may reveal a similar pattern of deep hybridization resulting in highly successful novel lineages.

Contrasting interspecific hybridization patterns in two goby groups radiating in divergent freshwater habitats

Abstract Hybridization and introgression between closely related species significantly affect their evolutionary and ecological processes. Understanding the ecological, environmental, and geographical conditions that promote their occurrence is imperative. It is hypothesized that species inhabiting geologically unstable habitats or with life-history constraints that prevent evasion from such environments are more prone to interspecific hybridization, due to limited development of prezygotic isolation. To test this hypothesis, we conducted a comparative analysis of genome-wide hybridization patterns in two freshwater goby groups of Gymnogobius: the castaneus- and urotaenia-groups. Utilizing the newly determined draft genome of G. isaza and single nucleotide variants identified by RNA sequencing, we first established the species phylogeny and then examined genetic signatures of interspecific hybridization in each group. The results revealed that all castaneus-group species, which primarily inhabit unstable habitats such as ponds, have undergone interspecific hybridization. Conversely, no species of the urotaenia-group showed clear evidence of hybridization over a period of more than 1 million years. These species inhabit an ancient lake (one species) or rivers (three amphidromous species), the latter possessing potential dispersal abilities in early life to evade geological disturbances. These ecology–geology relationships have remarkable implications for the intricate processes of adaptation and speciation.

Courtship dance similarity, but not complexity, may explain patterns of hybridization in manakins (Aves: Pipridae)

Abstract Differences in behaviour can play an important role in the emergence of species and the maintenance of species boundaries. In birds, behavioural isolation mechanisms range from simple vocalizations to elaborate courtship displays. The breakdown of these isolation mechanisms could result in the production of viable hybrid offspring. In general, we might expect a negative relationship between the complexity of a behavioural isolation mechanism and the incidence of hybridization. I tested this prediction in manakins, a Neotropical bird family that shows a large variety of courtship displays. I compiled a database of reliable hybrid records and quantified the complexity of species-specific courtship displays. Binary logistic regressions indicated that courtship similarity was a better predictor of hybridization probability than courtship complexity. However, this pattern was strongly influenced by phylogenetic relatedness, in that closely related species exhibited similar courtship displays that were already being performed by their common ancestor. The main limitation of this study concerns the incomplete dataset. I could assess the courtship complexity for only 22 manakin species; consequently, not all hybrid combinations could be included in the analyses. Nonetheless, these findings provide important insights into the role of courtship displays in explaining patterns of hybridization.

Junior-secondary Chinese history curricula in Hong Kong and mainland China: two patterns of approach hybridization

ABSTRACT This study explores how Hong Kong’s latest Chinese history curriculum hybridizes Romantic and Enlightened approaches and how that hybridization converges with/diverges from mainland China’s, given the two societies’ increased integration in the People’s Republic of China. Data were drawn from Hong Kong’s and mainland China’s latest junior-secondary Chinese history curricula policies and textbooks and Hong Kong’s earlier curriculum. Despite approaching mainland China’s Chinese history in curriculum structure and promoting China as a unified multi-ethnic nation, Hong Kong’s latest history curriculum retains its earlier orientation towards the Communist Party of China and the Enlightened approach. Hong Kong’s junior-secondary Chinese history curricula try to balance Romantic and Enlightened approaches, while mainland China’s symbolically promotes and selectively uses the latter to serve the former. Theoretical and practical implications and directions for future study are provided.

Knowledge Contestation of Midwives and TBAS: Study of Patterns of Domination, Hybridization, and Coexistence in Childbirth

Purpose: This study aims to analyze the contestation between the medical knowledge of midwives and the local knowledge of traditional birth attendants in accompanying pregnant women to delivery in the Gowa Regency. We also investigate the contestation between the medical knowledge of midwives and the local knowledge of traditional birth attendants in postnatal and infant care. Method: The research method uses a qualitative approach with case studies and data collection through interviews, observation, and documentation. Results and conclusion: The results identified three patterns of knowledge contestation between midwives and shaman uncles, namely domination, hybridization, and coexistence. Domination occurs in the context of pregnancy, where the knowledge of the shaman Pamana dominates the midwife, while hybridization occurs during the delivery process with collaboration between the midwife and the shaman Pamana. The pattern of coexistence illustrates that the knowledge of midwives and shaman Pamana is present together without interfering with each other in postnatal care. Research implications: This research is relevant to the maternal and newborn health system in Gowa Regency with the following implications: 1) Integration of medical and local knowledge is needed in the practice of midwives and birth attendants, emphasizing the need for holistic training for health service providers; 2) Collaboration between midwives and traditional birth attendants can improve the safety of mothers and babies; 3) Cultural awareness is important to improve quality of care; 4) Culturally sensitive practice guidelines are necessary for safe and effective practice; 5) Public advocacy and education can increase awareness of appropriate care. Originality/value: This research reveals the dynamics of contestation between medical and local knowledge in maternal and neonatal health services, providing new insights into their interactions. These findings support the development of more effective interventions, contribute to the reproductive health literature, and provide insights for more inclusive policies.

Probing the electronic structure, optical, and transport nature of lanthanide-based ternary materials: A First-principles perspective

High thermal stability and adjustable optoelectronic properties are the unique characteristics of lanthanide-based materials. The complex interplay between unique electronic, optical, and thermoelectric characteristics of lanthanide-based ternary chalcogenides is investigated by first principles modeling. The cohesive energy values were anticipated to be −4.54 eV/atom for PrSF and −4.87 eV/atom for PrSBr suggesting PrSBr to have the greatest bonding properties and is the most stable material. The computed formation energies range from −1.3 to −3.0 (eV/f. u), demonstrating their stability. The inclusion of bromine, a more electronegative element than fluorine, produces unique hybridization patterns and spin polarization effects. Compared to PrSBr, PrSF bonding employs more effective orbital hybridization, resulting in a greater band gap. PrSF has a higher frequency dielectric constant compared to PrSBr. The absorption edges in the ε2(ω) result from optical transitions between the Pr-f, S-p, F-p, and Br-p states. As the temperature rises, the Seeback coefficients for PrSF and PrSBr decrease exponentially. The thermal conductivity spectra of PrSF and PrSBr materials exhibit a linear increase across the temperature range. As temperature rises, the concentration of carriers and mobility increases, resulting in increased electrical conductivity values.