Amplified Fragment Length Polymorphism Research Articles

CAGn Polymorphic Locus of Androgen Receptor (AR) Gene in Russian Infertile and Fertile Men

The androgen receptor (AR) is critical for mediating the effects of androgens. The polymorphic CAGn locus in exon 1 of the AR gene is associated with several diseases, including spinal and bulbar muscular atrophy (SBMA), prostate cancer, and male infertility. This study evaluated the CAGn locus in 9000 infertile Russian men and 286 fertile men (control group). The CAGn locus was analyzed using the amplified fragment length polymorphism method. In the infertile cohort, the number of CAG repeats ranged from 6 to 46, with a unimodal distribution. The number of CAG repeats in infertile and fertile men was 22.15 ± 0.93 and 22.02 ± 1.36, respectively. In infertile men, variants with 16 to 29 repeats were present in 97% of the alleles. A complete mutation (≥42 CAG repeats) was found in three patients, while three others had 39-41 repeats. The incidence of SBMA was 1:3000 infertile men. Significant differences (p < 0.05) were observed between infertile and fertile men in alleles with 21, 24 and 25 repeats. This study revealed certain differences in the CAGn polymorphic locus of the AR gene in Russian infertile and fertile men and determined the frequency of SBMA in infertile patients.

Internal validation of the Precision ID GlobalFiler NGS STR panel v2 kit with locus-specific analytical threshold, and with special regard to mixtures and low template DNA detection

We performed an internal laboratory validation of the Precision ID GlobalFiler NGS STR panel v2 kit to assist the introduction of the technology into the routine forensic casework practice. The study was designed and evaluated based not only on the key validation standards like sensitivity, stability, reproducibility, repeatability, mixture, and concordance, but we also tested the effect of reduced input DNA, we measured and applied locus-specific analytical threshold values, tested two different PCR cycle conditions, sequence artifacts and stutters were also analysed. During the study we also tested the new method on real casework samples. The sensitivity study confirmed that adding 500 pg template DNA for library preparation can be optimal at base PCR cycle number (that was 24), because the measured average heterozygote balance was not lower than 0.82, and each allele was detected above the analytical threshold. However, contrary to previous communications, increasing the PCR cycle numbers up to 28 has not resulted the significant elevation of the heterozygote imbalance. According to our results, raised PCR cycle condition (i.e. 28) is appropriate at or below 150 pg total input DNA. For most loci, the calculated AT was lower than the manufacturer’s recommended. Applying the newly established ATs with raised PCR cycle conditions the allele detection sensitivity and reliability increased. We observed allele dropouts only at the 15 pg template DNA experiments with 5 % frequency, that is better to previously published studies. This result indicates that this low amount of DNA (i.e. 15 pg) could be a minimum limit of template input for a potentially successful analysis. In the mixture study the minor contributor could be detected up to 1:19 mixture ratio. We detected minor alleles in all measurements and concentrations above the threshold if the template DNA were fixed and only SNP differences were observed between the same alleles of the contributors. To test concordance between the new method and traditional STR genotyping we analysed 58 Hungarian individual samples in parallel. Nearby the detected 248 different length-based alleles on the 31 loci in the sample pool we revealed additional 75 sequence variant alleles, that represent an approximately 23 % increase in the total number of observed alleles. The casework study confirmed that the Precision ID GlobalFiler NGS STR panel v2 kit is effective even in genotyping degraded samples with extremely low levels of DNA, if we apply elevated cycle number for library preparation and use locus-specific analytical thresholds.

Molecular epidemiology of seborrheic dermatitis/dandruff associated Malassezia species from northern India.

Malassezia is a commensal that sometimes become pathogenic under the influence of diverse factors. Several species of Malassezia are difficult to culture, making traditional methods of identification challenging. The problem with molecular typing of Malassezia in association with seborrheic dermatitis/dandruff (SD/D) arises due to the unavailability of these fastidious yeast cultures. The aim of the study was to investigate the association between fluorescent amplified fragment length polymorphism (FAFLP) genotypes, disease state (SD/D), and the geographic distribution of M. globosa, M. restricta and M. arunalokei. In total 154 isolates representing M. globosa (n=85), M. restricta (n=55), and M. arunalokei (n=14) from lesional/non-lesional areas of SD/D patients and healthy controls residing in the rural (n=77) and urban (n=77) areas of northern India were included. A strategy based on the FAFLP methodology was developed using two endonuclease enzymes (EcoRI and HindIII). M. globosa, M. restricta, and M. arunalokei formed eleven, three, and two FAFLP clusters respectively. Disease-specific strains of M. restricta and M. arunalokei preferentially tend to cause SD/D. M. restricta and M. arunalokei showed less genetic variation. M. globosa showed higher genetic diversity. FAFLP clusters revealed the existence of geographically specific strains in M. restricta, M. arunalokei, and M. globosa. Our findings suggest that certain Malassezia strains are not only disease-specific but also geographically distinct.

Comparison of commercial targeted amplicon sequencing assays for human remains identification casework.

Targeted amplicon sequencing (TAS) facilitates the genotyping of forensically informative single nucleotide polymorphisms (SNPs) using massively parallel sequencing (MPS). For human remains identification, where any extracted DNA is likely to be degraded, TAS may succeed when short tandem repeat (STR) profiling using capillary electrophoresis fails. Further, as well as yielding identity information, SNPs can provide information about ancestry, phenotype, kinship and paternal lineage (Y chromosome haplotypes). Two TAS platforms were compared in this study: Ion AmpliSeq™ panels coupled with Ion Torrent sequencing on an Ion GeneStudio™ S5 Plus System, manufactured by Thermo Fisher Scientific, and the ForenSeq® Kintelligence Kit coupled with Illumina sequencing on the MiSeq FGx® Sequencing System, manufactured by QIAGEN. Four Ion AmpliSeq™ panels (Precision ID Identity, Precision ID Ancestry, DNA Phenotyping and HID Y-SNP) share 177 SNPs with the ForenSeq® Kintelligence Kit and all five were used to profile the DNA extracted from the petrous part of the temporal bone from six skeletonised cadavers. Of the 6 × 177 = 1,062 SNP genotype comparisons, 1,055 (99%) were concordant between the Ion AmpliSeq™ panels and Kintelligence Kit. Of the seven (< 1%) non-concordant SNPs, only three of them (0.3%) would have resulted in erroneous genotypes being reported as a result of allele dropout by either assay, using our optimised relative variant frequency windows for allele calling. We conclude that both the Ion AmpliSeq™ panels and the ForenSeq® Kintelligence Kit were suitable for TAS applied to the human remains in this study.

Genetic diversity and structure of Tunisian and Indian date palm (Phoenix dactylifera and sylvestris) cultivars and genotypes revealed by AFLP markers

The date palm breeding programs need to discover valid genetic fingerprints to characterize cultivars and assess their genetic diversity. This study assessed the genetic diversity among thirty-nine date palm cultivars from Tunisia (Phoenix dactylifera) and India (Phoenix sylvestris) by using six AFLP (Amplified Fragment Length Polymorphism) markers. 360 loci were amplified, with 127 loci polymorphic (34.35 %). The Jaccard's similarity coefficient ranged from 0.161 to 0.931, with the mean genetic distances of 0.568. AFLP's average marker index value was 7.28, with a resolving power of 10.91. The analysis of population structure showed two main clusters with a clear separation between Tunisian and Indian cultivars.Furthermore, the heatmap analysis allowed the identification of 10 bands specific to the Indian accessions, which were not detected in Tunisian genotypes. These loci could be linked to genes involved in adapting the species in Indian lands, which allowed the study of the genetic diversity of date palm resources of different origins, confirming the existence of at least two origins of domestication. Additionally, identifying AFLP loci specific to P. dactylifera and P. sylvestris will significantly contribute to breeding programs by exploiting species-specific polymorphisms.

Changes in global methylation patterns of Mytilus galloprovincialis exposed to microplastics

Microplastics (MPs) disturb the normal activity of aquatic organisms at different levels, causing physiological stress and altering feeding, growth, and reproduction. Alterations of epigenetic patterns due to exposure to MPs have scarcely been studied in invertebrates. In this study, Mytilus galloprovincialis mussels (N = 61) were intermittently exposed to different concentrations of pure polystyrene microbeads for three weeks. The concentrations used in this research were similar to those currently found in certain polluted environments (E1), as well as higher doses to which mussels could be further exposed (E2 and E3). After exposure period, the global methylation patterns were investigated using Amplified Fragment Length Polymorphism (AFLPs). Significantly lower methylation was found in exposed groups compared to the control group. The level of hypomethylation increased with the concentration of microbeads. Similar results were found from field samples inhabiting two sites differentially MPs-polluted. The implications of this discovery were analysed and discussed, noting the already known effects of MPs on metabolism and cell division. Further studies on this and other sentinel organisms are recommended to understand the response of the aquatic species to the currently increasing MPs pollution.

Taxonomic identification of Nigerian Terminalia superba and Terminalia ivorensis Combretaceae) using AFLP molecular markers

Terminalia superba and T. ivorensis are difficult to identify with morphological markers. Molecular characterization is very effective to correct the delimitation of timber species, especially when the discriminatory power of morphological markers is weak. In this study, four amplified fragment length polymorphism (AFLP) marker combinations were used to determine the taxonomic relationship among a total of 33 accessions of the genus Terminalia, consisting of two species, Terminalia ivorensis (12 accessions) and T. superba (21). The primer combinations produced a total of 740 fragments out of which 619 (83.6%) were polymorphic. Among all the primer combinations used, E-ACT/M-CTC was the most informative, which generated 11 unique markers for clear identification of the two species. The average polymorphic information content (PIC) ranged from 0.24 (E-ACT/M-CAT) to 0.28 (E-ACT/M-CTC) while the resolving power (RP) varied from 40.73 (E-AAC/M-CTA) to 63.76 (E-ACT/M-CTC). The genetic difference between the two species was significant (PhiPT = 0.610, p&lt;0.001). All 33 accessions were delimited by both the UPGMA cluster and principal component analysis. Based on the results, it was concluded that E-ACT/M-CTC is the best among the marker combinations used for molecular study of the two tree species and used significantly to distinguish them. STRUCTURE analysis identified two accessions of Terminalia superba with alleles derived from T. ivorensis as well as revealed five putative hybrid accessions, which requires further genetic investigation to substantiate the finding.

A wide range of abiotic habitat factors and genetic diversity facilitate expansion of Trapa natans within its native range

Climate change and intense human activity are exacerbating changes in species' ranges. While the rapid spread of invasive alien species is well documented worldwide, the phenomenon of the spread of native species is poorly understood. To explain the problem of rapidly spreading species in the changing world, it is necessary to understand their ecology, genetic diversity and habitat limitation. The aim of our study was to analyze the ecological requirements and genetic diversity in the population of the macrophyte Trapa natans s. l., an invasive alien species in North America but native in Europe and Asia. We investigated the populations in its native range (Central and Northeastern Europe), where the species is defined as rare or extinct. We found the occurrence of T. natans in Northeastern Europe aquatic habitats where, up to now, it was described as an extinct species. The results of our environmental studies showed that the species has a wide range of tolerance to habitat conditions and lives in medium to highly nutrient-rich water with low and high salinity. Using Amplified Fragment Length Polymorphism (AFLP) analysis, we revealed high genetic variability within populations with relatively limited differentiation between populations. We showed that some populations are highly diverse (possibly refugia; Central Europe) and others are homogeneous (new sites, commercial reintroduction; Northeastern Europe). Conservation status of T. natans in its native range should be reconsidered, as the species has spread rapidly in recent decades and could be detrimental to aquatic habitats. The conclusion is that expansion/invasion can start from small populations, but under favorable conditions these populations spread rapidly. The introduction of species (even native) should be done carefully, if at all, as uncontrolled introduction to new locations, e.g. private ponds, could be the start of dispersal (native habitats) or invasion (non-native area).

Troubleshooting apparent allelic dropout using two methods: of next generation sequencing

Troubleshooting apparent allelic dropout using two methods: of next generation sequencing

Genomic Association and Prediction Study for Yield Traits in a Sugarcane (Saccharum spp. Hybrids) Mapping Population ‘LCP 85‐384’

ABSTRACTSugarcane (Saccharum spp. hybrids) are complex polyploid and aneuploid interspecific hybrids with 110–130 chromosomes. A traditional sugarcane breeding cycle takes 13–15 years and involves multiple years and locations testing of yield. To identify molecular markers associated with yield‐related traits, the LCP 85‐384 cultivar and its mapping population of 263 self‐progenies were planted in two randomly replicated field plots. The mapping population was genotyped with amplified fragment length polymorphism (AFLP), simple sequence repeats (SSR) and target region amplification polymorphism (TRAP) markers. Data on plant height, stalk number, stalk diameter and stalk weight were collected. A large variation was observed for each trait. A genome‐wide association study (GWAS) was conducted using mixed linear model (MLM), generalized linear model (GLM) and single marker regression (SMR) programmes of TASSEL 5 and FarmCPU of GAPIT 3. A total of 64 yield trait‐associated alleles were identified, including 11 for stalk number, 36 for stalk weight, 21 for stalk diameter and 5 for plant height. Of the 64 alleles, seven were linked to two traits and one to three traits. Genomic prediction (GP) was also performed by cross‐prediction with five models, namely, ridge regression best linear unbiased prediction (rrBLUP), Bayesian ridge regression (BRR), Bayesian A (BA), Bayesian B (BB), and Bayesian least absolute shrinkage and selection operator (BL). Prediction accuracy (r value) reached 0.40 for plant height, 0.36 for stalk number, 0.44 for stalk diameter and 0.54 for stalk weight with the standard errors from 0.009 to 0.012. Once verified, these markers will be a valuable tool to aid in the selection of yield‐related traits in sugarcane improvement programmes.

Genetic Diversity and Population Genetic Structure of Jatropha curcas L. Accessions from Different Provenances Revealed by Amplified Fragment-Length Polymorphism and Inter-Simple Sequence Repeat Markers

The genetic diversity and structure of 17 populations of J. curcas, including 92 accessions from different provenances (tropical and subtropical), were investigated and effectively evaluated using twelve inter-simple sequence repeats (ISSRs) and seven pairs of florescence-amplified fragment-length polymorphism (AFLP) primers. Genetic diversity, at the overall level among populations of J. curcas based on the ISSR markers, showed that the observed number of alleles (Na) was 1.593, the effective number of alleles (Ne) was 1.330, Nei’s gene diversity (H) was 0.200, Shannon’s information index (I) was 0.303, and the percentage of polymorphic loci was 59.29%, indicating moderate genetic diversity between and within the different populations of J. curcas. Based on the genetic diversity analysis of AFLP markers, there were 1.464 (Na) and 1.216 (Ne) alleles, Nei’s gene diversity (H) was 0.132, Shannon’s information index (I) was 0.204, and the percentage of polymorphic loci was 46.40%. The AMOVA analysis showed that this large variance was due to differences within the populations, with genetic distinctions and limited gene flow among those from varied regions. The 17 populations were clustered into five main groups via UPGMA clustering analysis based on Nei’s genetic distance, and the genetic relationships among the populations exhibited no significant correlations with geographical provenances. The genetic variation among Chinese populations of J. curcas distributed in dry-hot valley areas was remarkable, and the American germplasm presented with distinct genetic differentiation.

Performance comparison of a previously validated microhaplotype panel and a forensic STR panel for DNA mixture analysis

Short Tandem Repeats (STRs) are the most widespread markers in forensic genetics. However, STR stutter peaks can mask alleles from a minor contributor when analysing mixtures, hindering the interpretation of complex profiles. In this study we compared the performance of a previously described panel of microhaplotypes (MHs), an alternative type of forensic marker, against a standard STR kit. The parameters evaluated included: capability of determining the minimum number of contributors in the mixture; percentages of allele drop-outs and drop-ins; retrieval of alleles belonging to the minor contributor, and estimation of likelihood ratio (LR) values. In addition, the capacity of EuroForMix software to estimate each donor’s percentage of contribution was tested, as well as the impact on results when using manually, or automatically prepared libraries. The MH panel showed better performance than STRs for the detection of 2-contributor mixtures, but the lower degree of polymorphism per MH marker hindered the task of deconvolution with multiple contributors. MHs presented higher drop-in rates and lower drop-out rates, a higher capability to recover the minor contributor’s alleles and provided higher LR values than STRs, likely due to the much higher number of loci combined in the panel. Estimations of contributor ratios using EuroForMix showed promising results and marginal differences were found in these values between manually and automatically prepared libraries. Overall, results showed that the mixture detection performance of the MH panel was better or equal to the standard forensic autosomal STR panel, indicating microhaplotypes are informative markers for this purpose.

The Emergence of New Sporothrix brasiliensis Genotypes in Current Epidemic of Sporotrichosis in Southeastern Brazil.

Zoonotic sporotrichosis caused by Sporothrix brasiliensis has become the main subcutaneous mycosis in Brazil. Minas Gerais (MG) is located in southeast Brazil and since 2015 has experienced an epidemic of zoonotic sporotrichosis. This study aimed to reconstruct the epidemiological scenario of sporotrichosis from S. brasiliensis in recent epizooty in the Metropolitan Region of Belo Horizonte (MRBH), MG. A total of 95 Sporothrix spp. isolates (Sporothirx brasiliensis n = 74, S. schenckii n = 11 and S. globosa n = 10) were subjected to Amplified Fragment Length Polymorphism (AFLP) genotyping and mating-type analysis to determine genetic diversity and population structure. Of these, 46 S. brasiliensis isolates were recovered from animals (cats n = 41 and dogs n = 5) from MRBH. Our study describes the high interspecific differentiation power of AFLP-based genotyping between the main phylogenetic Sporothrix groups. S. brasiliensis presents high genetic variability and pronounced population structure with geographically focused outbreaks in Brazil. The genetic groups include older genotypes from the prolonged epidemic in Southeast (Rio de Janeiro and São Paulo), South (Rio Grande do Sul), Northeast (Pernambuco) and new genotypes from the MRBH. Furthermore, we provide evidence of heterothallism mating strategy in pathogenic Sporothrix species. Genotypes originating in Rio de Janeiro and Pernambuco carry the predominant MAT1-2 idiomorph as opposed to genotypes from Rio Grande do Sul, which have the MAT1-1 idiomorph. We observed an overwhelming occurrence of MAT1-1 among MRBH isolates. Our study provides clear evidence of the predominance of a genetic group profile circulating in animals in Minas Gerais, independent of that disseminated from Rio de Janeiro. Our data can help us understand the genetic population processes that drive the evolution of this fungus in Minas Gerais and contribute to future mitigation actions for this ongoing epidemic.

Pythium and Globisporangium species associated with cucumber rhizosphere causing damping-off and their effects on cucumber seed decay in Oman.

Pythium sensu lato (s.l.) is a pathogenic oomycete. The present study was conducted to isolate and identify Pythium s.l. species associated with the rhizosphere and roots of greenhouse-growing cucumbers showing damping-off symptoms in 10 Omani governorates (provinces). A total of 166 isolates were recovered from 276 rhizosphere soil and root samples and were identified based on the ribosomal DNA (rDNA) internal transcribed spacer (ITS) region and the cytochrome c oxidase subunit I (COX I) gene region. Pythium aphanidermatum, P. myriotylum, Globisporangium spinosum, Globisporangium sp.1 (isolates Kb003/PySyCu-1 and Kb004/PySyCu-2), and Globisporangium sp.2 (isolate Ib002R) were identified. Among these species, P. aphanidermatum was the most abundant species, represented by 143 isolates (86.1%), followed by G. spinosum with 18 isolates (10.8%), Globisporangium sp.1 and P. myriotylum each with 2 isolates (2.4%), and Globisporangium sp.2 with 1 isolate (0.6%). Pathogenicity tests were also conducted for 38 isolates, including P. aphanidermatum (25), P. myriotylum (2), Globisporangium sp.2 (1), G. spinosum (8), and Globisporangium sp.1 (2). Among the tested isolates, only Globisporangium sp.2 isolate was avirulent, and none of the seeds were rotted at the end of the treatment. However, the other species induced the symptoms of seed decay with the incidence ranged from 86.7 to 100%. Phylogenetic analyses were conducted based on 222 ITS and 53 COX I sequences, and confirmed morphological identification. In addition, the genetic diversity of 93 P. aphanidermatum isolates was assessed via the amplified fragment length polymorphism (AFLP) method. The analysis produced 93 genotypes and 449 polymorphic loci. Pythium aphanidermatum populations were found to have moderate levels of genetic diversity (H = 0.2) and a moderate Shannon information index (I = 0.3793). Analysis of molecular variance (FST = 0.1, P = 0.0) revealed a moderate level of genetic differentiation among P. aphanidermatum isolates between Oman governorates. The sensitivity of 15 P. aphanidermatum isolates was evaluated against hymexazol at different concentrations (10, 100, and 1000ppm). The results revealed that P. aphanidermatum could grow well at concentrations of up to 100ppm hymexazol. However, hymexazol at 1000ppm retarded the growth of P. aphanidermatum. This study showed that P. aphanidermatum is the most prevalent species in greenhouses in Oman and exhibited a moderate level of genetic diversity. Most of the isolates exhibited differences in tolerance to hymexazol but showed no resistance.

Early Candida colonisation impact on patients and healthcare professionals in an intensive care unit.

Candida spp. is an opportunistic pathogen that causes superficial and invasive infections with nosocomial outbreaks without strict hygiene protocols. Herein, we assessed oral colonisation by Candida spp. in 209 Intensive Care Unit (ICU) patients between July 2021 and April 2022, conducting clinical, epidemiological, and microbiological characterisation of those developing oral or invasive candidiasis. Initial oral swabs were collected within 24 h of admission in the ICU, followed by collections on Days 2, 4, 6 and 8. Swabs from denture-wearing patients, abiotic surfaces, healthcare professionals' hands, and retroauricular regions were also obtained. Recovered yeasts and filamentous fungi were identified using MALDI-TOF MS and morphological characteristics, respectively. Genetic similarity of Candida spp. isolates was evaluated using Amplified fragment length polymorphism (AFLP), and the antifungal susceptibility profile was determined by broth microdilution. In the study, 64.11% of patients were orally colonised by Candida spp. Of these, 80.59% were colonised within the first 24 h. Oral colonisation also occurred on subsequent days: 50%/Day 2, 26.92%/Day 4, and 11.53%/Days 6 and 8. Of the patients, 8.61% had oral candidiasis, mainly pseudomembranous. Among orally colonised patients, 2.23% developed invasive candidiasis. Besides, 89.47% of healthcare professionals evaluated were colonised. MALDI-TOF MS identified different yeast species, and C. albicans (45.34%), C. tropicalis (15.7%), and C. parapsilosis sensu stricto (9.88%) were the most prevalent. AFLP analysis indicated a high genetic correlation (≥97%) between C. parapsilosis sensu stricto isolates from patients and professionals. Three resistant C. albicans isolates were also found. This study reported a diversity of yeast and filamentous fungi species in ICU patients and highlighted early Candida spp. colonisation risks for invasive candidiasis, as well as the potential horizontal transmission in the nosocomial setting, emphasising the need for effective infection control measures.

Emerging Cases of Cat-Transmitted Sporotrichosis Driven by Sporothrix brasiliensis in Northeast Brazil.

Cat-transmitted sporotrichosis is caused by the emerging fungal pathogen Sporothrix brasiliensis and constitutes a significant public health issue that affects people living in resource-poor urban centers in Brazil. The lack of knowledge about transmission dynamics makes it difficult to propose public health policies to contain the advance of sporotrichosis. We describe the recent emergence of 1,176 cases of sporotrichosis in cats (2016 to 2021) in the metropolitan region of Recife, Brazil, leading to significant zoonotic transmission and an overwhelming occurrence of S. brasiliensis as the etiological agent. Most cases were from cats in the cities of Olinda (408/1,176; 34.70%), Jaboatão dos Guararapes (332/1,176; 28.23%), and Recife (237/1,176; 20.15%). Molecular typing using amplified fragment length polymorphism (EcoRI-GA/MseI-AG) revealed low polymorphic information content (PIC = 0.2499) and heterozygosity (H = 0.2928), typical of an outbreak scenario. Dendrogram and multivariate cluster analysis revealed that isolates from Pernambuco are closely related to Rio de Janeiro isolates. We report a substantial occurrence of MAT1-2 idiomorphs in the metropolitan region of Recife (0:60 ratio; χ2 = 60.000, P < 0.0001). The limited population differentiation and genetic diversity of the isolates from Pernambuco suggest a recent introduction, possibly via a founder effect, from the parental population in Rio de Janeiro. Our findings emphasize the critical importance of molecular surveillance of S. brasiliensis for outbreak response. A comprehensive one-health strategy is mandatory to control the spread of cat-transmitted sporotrichosis driven by S. brasiliensis, encompassing sanitary barriers, quick diagnosis, and treatment.

Carpinus austrobalcanica – A new highly polyploid species from the Balkan Peninsula closely related to European hornbeam

The Balkan Peninsula was the primary glacial refugium for many temperate tree species and contributed overproportionally to the postglacial recolonisation of central and eastern Europe. This is also the case for Carpinus betulus, the European hornbeam, whose main glacial refugium was in the Balkans. During our fieldwork in the southern Balkans, we discovered trees with a morphology similar to that of C. betulus, but differing in their rough, highly rigged bark and the shape of their fruit involucre. The aim of this study was to investigate the evolutionary origin and differentiation of these morphologically distinct populations of C. betulus from the North Pindus Mountain range in northern Greece and southern Albania using an integrative approach. Our study combined phylogenetic analyses of plastid and nuclear internal transcribed spacer sequences, amplified fragment length polymorphism fingerprinting, relative genome size estimation, and multivariate morphometric analyses. After establishing the genetic and morphological divergence of the aforementioned populations, we described them as a new species, Carpinus austrobalcanica D.Lakušić, Kuzmanović, Stevanoski, Schönsw. & Frajman, sp. nov. We provide diagnosis, description, geographical distribution, and conservation status of this enigmatic newly described tree species locally endemic to the southern Balkans.

Interspecific Hardy Geranium Progenies: Morphological Characterization and Genetic Evaluation

Hardy geranium is a popular ornamental plant with a high market demand. As a result, there is a strong need for continuous innovation to improve its ornamental qualities. Interspecific hybridization is a widely used technique for introducing desirable traits and creating new cultivars with added value. To explore the possibilities of creating novelty within the Geranium genus, we conducted 2438 interspecific crosses over three flowering seasons, resulting in the successful harvest of 445 seeds and the final production of 82 seedlings. Using embryo rescue increased the germination rate of a seedling from 0.17% to 1.01%. To validate the paternal genetic contribution in the new seedlings, we used amplified fragment length polymorphism (AFLP) to assess the proportion of uniquely inherited paternal markers in all seedlings. AFLP analysis confirmed that 54 of the 82 seedlings were indeed true hybrids (65.8% hybridization success rate). A morphological evaluation of the flowers and leaves, including flower diameter (mm), style length (mm), number of flowers, flowering period (weeks), and color of both flowers and leaves, provided further confirmation of the F1 hybrid status of the seedlings. The results of our interspecific breeding demonstrated the efficiency of interspecific hybridization in hardy geraniums and its potential to create distinctive and novel cultivars for the ornamental market.

P-551 Application of simultaneous PGT-M/PGT-A using whole genome sequencing and haplotyping for monogenetic disorders, multiple variants, low penetrance, and de novo disorders

Abstract Study question Is the concurrent use of high-resolution PGT-A and genome-wide haplotyping with disease-specific assays for PGT-M effective in an unselected patient population at-risk for monogenetic disorders? Summary answer PGT-A/PGT-M is an effective treatment for couples/patients burdened with genetic diseases, that provides optimal family planning, prevents vertical transmission, and reduces personal and societal encumbrance What is known already Societal awareness of genetic testing expanded the use of carrier screening, diagnostic genetic tests, and higher in vitro fertilization (IVF) utilization has increased demand for preimplantation genetic testing for monogenetic disorders (PGT-M), as an alternative to invasive prenatal tests. The scope of PGT-M testing expands beyond common severe childhood disorders, to include serious and mild late onset disorders, cancer predisposition, variants of unknown significance, de novo mutations, and variants in multiple genes. This highlights novel ethical dilemmas, necessitating adjustment of generic genome wide approaches to complement, or eventually replace, targeted disease-specific PGT-M assays. Study design, size, duration This is a retrospective study of 359 couples at-risk for monogenetic disorders referred to the CReATe Fertility Centre, Toronto, Canada. Our objective was to evaluate the efficiency of concurrent use of genome wide haplotyping and disease specific assays for PGT-M and high resolution PGT-A in an unselected patient population at risk for monogenetic disorders, multiple and de novo variants, low penetrance and variants of unknown significance. Participants/materials, setting, methods All patients received comprehensive genetic counselling. For each couple/patient, DNA from gamete providers, related family member/s and whole-genome amplified (WGA)DNA from a single trophectoderm(TE) biopsy were analyzed. Whole-genome SNP-array (Karyomapping, Illumina, CA) and STR-analysis were used to obtain parental haplotypes and Sanger-sequencing was used for direct variant analysis. PGT-A was performed using Illumina platform(NextSeq 550). NxClinical (BioDiscovery) and BlueFuse Multi(Illumina) software were used for data analysis. Main results and the role of chance 1826 embryos, from 235 IVF cycles were analyzed for 88 unique genes (14 cancer predisposing, 42 autosomal recessive and 32 dominant genes) and a total of 282 unique variants. The most frequent genes tested were BRCA1/2 -21% of all cases, followed by HBB-8.7%, CFTR-8.7% and CYP21A2-8.7%. PGT-M for 11 cases was done for a de novo variant detected in a sibling and in 2 cases for a parental mosaic variant. Multiple genes and VUS were analyzed in 12 and 6 cases, respectively. PGT-A analysis showed 31.6% aneuploidy, 9.6% mosaicism and 58.8% euploidy. Genome wide haplotyping was used for euploid and mosaic embryos with an average case call rate of 95%, and average case Allele Drop Out (ADO) rate of 2.7%. Recombination events in 3% of cases prevented assignment of haplotype. Direct mutation testing was obtained for all samples and was 100% concordant with the predicted haplotypes. In cases with no predicted haplotype, direct testing established the PGT-M diagnosis. The distribution for both recessive and dominant disorders was in Mendelian order. To date 66 live births confirmed the results from PGT-M diagnosis. Limitations, reasons for caution Ethical considerations and extensive genetic counselling are prerequisites for PGT-A/M testing implementation. Simultaneous screening for embryo aneuploidy and monogenetic disorders optimizes patient treatment and family planning, but may not be available in all jurisdictions. Although the data was collected prospectively, retrospective design is a limitation. Wider implications of the findings Simultaneous PGT-A and PGT-M with direct variant testing provides optimal embryo prioritization for transfer and significantly reduces time to a healthy pregnancy in couples at risk for inherited disorders. Karyomapping is effective for generic haplotyping, with a low risk of undetected recombination events in the genomic region of interest. Trial registration number not applicable

O-095 Assessment of genome editing outcomes in human preimplantation embryos subjected to CRISPR-Cas9 – most loss of heterozygosity (LOH) events are caused by DNA repair deficiency

Abstract Study question What is the cause of loss of heterozygosity, frequently observed in embryos subjected to CRISPR-Cas9, an interhomolog-homologous recombination repair (IH-HR) or deficiency in DNA repair? Summary answer Vast majority of LOH observed in human zygotes subjected to CRISPR-based editing is explained by deficiency in DNA repair prior to genome activation, not IH-HR. What is known already Genome editing (GE) at the preimplantation stage, intended to correct disease-causing mutations, is controversial due to safety and ethical concerns. It has been suggested that a high frequency of LOH seen in zygotes subjected to GE could be explained by resolution of the double-stranded DNA breaks (DSBs) created using CRISPR-Cas9 by interhomolog-homologous recombination repair (IH-HR), a process with potential to correct deleterious heterozygous mutations. However, such hypotheses are controversial and it is unclear whether embryos at this stage development can utilise IH-HR. CRISPR-Cas9 targeted sites are difficult to interrogate with traditional methods, risking a misinterpretation of editing outcomes. Study design, size, duration We hypothesised that the frequently observed LOH affecting the CRISPR-targeted sites in human zygotes is caused by the deficiency in DNA repair at this developmental stage, resulting in complex genotypes which traditional molecular methods have failed to detect, and not IH-HR which uses the second un-cleaved parental allele as a template for repair. DSBs were induced at three genomic sites in embryos microinjected at the time of fertilisation (n = 27) in this IRB-approved study. Participants/materials, setting, methods Research embryos were cultured for 60 hours, then disaggregated. Individual cells underwent an array of genetic tests, including NGS, allowing determination of the repair pathway utilised and revealing any cytogenetic abnormalities. A novel state-of-the-art analytical workflow was developed to interrogate 25kb around CRISPR cleavage sites. This approach provided a means of detecting complex genomic rearrangements as well as unresolved DNA damage, which would appear as LOH when employing traditional PCR-based approaches for assessment. Main results and the role of chance Induction of DSBs using CRISPR-Cas9 was 100% efficient when applied at the time of fertilisation. LOH was confirmed to be common at targeted sites, affecting 69/216 (32%) loci examined in 108 blastomeres. Remarkably, the great majority of LOH events (&amp;gt;90%) were a direct consequence of inappropriate/failed DNA repair (unresolved DNA breaks or complex genomic rearrangements). Strikingly, not a single instance of IH-HR was observed when CRISPR reagents were introduced at fertilisation. This may be explained by the physical separation of the two parental genomes in distinct pronuclei at that time. Allele-drop out (ADO), a technical problem, accounted for &amp;lt;10% of all LOH events. In total, 46% of DSBs failed to undergo appropriate repair, resulting in segmental aneuploidy (21%), large-scale deletions (10%), inversions/translocations (10%), or loss of the targeted chromosome (5%). 45% of DSBs were resolved using error-prone non-homologous end joining (NHEJ), while only 9% utilised the homology directed repair (HDR) pathway required for correction of mutations. Application of CRISPR-Cas9 to embryos on day-3 of development (after embryonic genome activation - EGA) was less efficient, only producing a DSB in 6/37 embryos (16%). However, the mode of repair differed markedly, 100% employing HDR (p = 0.0001). In 4 cases, this involved IH-HR. Limitations, reasons for caution This data provides strong evidence that LOH recorded in earlier studies was incorrectly attributed to IH-HR and was actually due to abnormal/failed repair. CRISPR appears more effective after EGA, with efficient DNA repair dominated by desirable HDR. However, a larger number of embryos is required to corroborate this finding. Wider implications of the findings The use of CRISPR-Cas9 at the time of fertilisation is frequently associated with problematic, unintended outcomes, rendering the technique clinically inapplicable in the current format. Careful study design which allows determination of all possible editing outcomes is essential and advances our understanding of the underlying mechanisms of DNA repair. Trial registration number not applicable