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Two new Psilocybe species (Hymenogastraceae), P. ingeli and P. maluti, are described from southern Africa. Morphology and phylogeny were used to separate the two novel fungi from their closest relatives in the genus. Psilocybe ingeli was found fruiting on bovine manure-enriched grasslands in the Kwa-Zulu Natal Province of South Africa and differs from its closest relative P. keralensis and others in the internal transcribed spacer ITS1-5.8S-ITS2, partial 28S nuc rDNA, and translation elongation factor 1-alpha regions, distribution, and having larger basidiospores. Similarly, P. maluti was collected from the Free State Province of South Africa and observed in the Kingdom of Lesotho, growing on bovine manure. A secotioid pileus, geographic distribution, and differences in the same DNA regions distinguish P. maluti from its closest relative P. chuxiongensis. Furthermore, the spore dispersal and traditional, spiritualistic use of P. maluti are discussed here.
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Introduction: COVID-19 vaccines are highly effective in inducing protective immunity. While the serum antibody response to COVID-19 vaccination has been studied in depth, our knowledge of the underlying plasmablast and memory B cell (Bmem) responses is still incomplete. Here, we determined the antibody and B cell response to COVID-19 vaccination in a naïve population and contrasted it with the response to a single influenza vaccination in a primed cohort. In addition, we analyzed the antibody and B cell responses against the four endemic human coronaviruses (HCoVs). Methods: Measurement of specific plasma IgG antibodies was combined with functional analyses of antibody-secreting plasmablasts and Bmems. SARS-CoV-2- and HCoV-specific IgG antibodies were quantified with an in-house bead-based multiplexed immunoassay. Results: The antibody and B cell responses to COVID-19 vaccination reflected the kinetics of a prime-boost immunization, characterized by a slow and moderate primary response and a faster and stronger secondary response. In contrast, the influenza vaccinees possessed robust immune memory for the vaccine antigens prior to vaccination, and the recall vaccination moderately boosted antibody production and Bmem responses. Antibody levels and Bmem responses waned several months after the 2nd COVID-19 vaccination, but were restored upon the 3rd vaccination. The COVID-19 vaccine-induced antibodies mainly targeted novel, non-cross-reactive S1 epitopes of the viral spike protein, while cross-reactive S2 epitopes were less immunogenic. Booster vaccination not only strongly enhanced neutralizing antibodies against an original SARS-CoV-2 strain, but also induced neutralizing antibodies against the Omicron BA.2 variant. We observed a 100% plasma antibody prevalence against the S1 subunits of HCoVs, which was not affected by vaccination. Discussion: Overall, by complementing classical serology with a functional evaluation of plasmablasts and memory B cells we provide new insights into the specificity of COVID-19 vaccine-induced antibody and B cell responses.
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Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , Reacciones Cruzadas , Inmunidad Humoral , Inmunoglobulina G , Células B de Memoria , Células Plasmáticas , SARS-CoV-2 , Humanos , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Células B de Memoria/inmunología , SARS-CoV-2/inmunología , Vacunas contra la COVID-19/inmunología , Masculino , Adulto , Reacciones Cruzadas/inmunología , Femenino , Células Plasmáticas/inmunología , Persona de Mediana Edad , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Vacunación , Vacunas contra la Influenza/inmunología , Memoria Inmunológica/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Epítopos de Linfocito B/inmunología , Linfocitos B/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , CinéticaRESUMEN
BACKGROUND: The pursuit of adaptive radiotherapy using MR imaging for better precision in patient positioning puts stringent demands on the hardware components of the MR scanner. Particularly in particle therapy, the dose distribution and thus the efficacy of the treatment is susceptible to beam attenuation from interfering materials in the irradiation path. This severely limits the usefulness of conventional imaging coils, which contain highly attenuating parts such as capacitors and preamplifiers in an unknown position, and requires development of a dedicated radiofrequency (RF) coil with close consideration of the materials and components used. PURPOSE: In MR-guided radiation therapy in the human torso, imaging coils with a large FOV and homogeneous B1 field distribution are required for reliable tissue classification. In this work, an imaging coil for MR-guided particle therapy was developed with minimal ion attenuation while maintaining flexibility in treatment. METHODS: A birdcage coil consisting of nearly radiation-transparent materials was designed and constructed for a closed-bore 1.5 T MR system. Additionally, the coil was mounted on a rotatable patient capsule for flexible positioning of the patient relative to the beam. The ion attenuation of the RF coil was investigated in theory and via measurements of the Bragg peak position. To characterize the imaging quality of the RF coil, transmit and receive field distributions were simulated and measured inside a homogeneous tissue-simulating phantom for various rotation angles of the patient capsule ranging from 0° to 345° in steps of 15°. Furthermore, simulations with a heterogeneous human voxel model were performed to better estimate the effect of real patient loading, and the RF coil was compared to the internal body coil in terms of SNR for a full rotation of the patient capsule. RESULTS: The RF coil (total water equivalent thickness (WET) ≈ 420 µm, WET of conductor ≈ 210 µm) can be considered to be radiation-transparent, and a measured transmit power efficiency (B1 +/ P $\sqrt {\mathrm{P}} $ ) between 0.17 µT/ W $\sqrt {\mathrm{W}} $ and 0.26 µT/ W $\sqrt {\mathrm{W}} $ could be achieved in a volume (Δz = 216 mm, complete x and y range) for the 24 investigated rotation angles of the patient capsule. Furthermore, homogeneous transmit and receive field distributions were measured and simulated in the transverse, coronal and sagittal planes in a homogeneous phantom and a human voxel model. In addition, the SNR of the radiation-transparent RF coil varied between 103 and 150, in the volume (Δz = 216 mm) of a homogeneous phantom and surpasses the SNR of the internal body coil for all rotation angles of the patient capsule. CONCLUSIONS: A radiation-transparent RF coil was developed and built that enables flexible patient to beam positioning via full rotation capability of the RF coil and patient relative to the beam, with results providing promising potential for adaptive MR-guided particle therapy.
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Imagen por Resonancia Magnética , Radioterapia Guiada por Imagen , Imagen por Resonancia Magnética/instrumentación , Humanos , Radioterapia Guiada por Imagen/instrumentación , Rotación , Diseño de Equipo , Fantasmas de Imagen , Ondas de Radio , Posicionamiento del Paciente/instrumentaciónRESUMEN
An expedient method for the synthesis of cyclic carbonates from homoallylic carbonic acid esters by means of photo-aerobic selenium-π-acid multicatalysis is reported. Until now, conceptually related methods commonly relied either on the stoichiometric addition of electrophiles onto the substrate's alkene moiety or the presence of pre-installed leaving groups in allylic position of said alkene to - in part, catalytically - initiate an intramolecular attack by an adjacent carbonic acid ester group. In sharp contrast, the current study shows that the C-C double bond of homoallylic carbonic acid esters can be directly activated by the catalytic interplay of a pyrylium dye and a diselane using ambient air as the sole oxidant and visible light as an energy source.
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Ethiopia is the largest wheat producer in sub-Saharan Africa yet remains a net importer. Increasing domestic wheat production is a national priority. Improved varieties provide an important pathway to enhancing productivity and stability of production. Reliably tracking varietal use and dynamics is a challenge, and the value of conventional recall surveys is increasingly questioned. We report the first nationally representative, large-scale wheat DNA fingerprinting study undertaken in Ethiopia. Plot level comparison of DNA fingerprinting with farmer recall from nearly 4000 plots in the 2016/17 season indicates that only 28% of farmers correctly named wheat varieties grown. The DNA study reveals that new, rust resistant bread wheat varieties are now widely adopted. Germplasm originating from CGIAR centres has made a significant contribution. Corresponding productivity gains and economic benefits have been substantial, indicating high returns to investments in wheat improvement. The study provides an accurate assessment of wheat varietal status and sets a benchmark for national policy-makers and donors. In recent decades, the Ethiopian wheat landscape has transformed from local tetraploid varieties to widespread adoption of high yielding, rust resistant bread wheat. We demonstrate that DNA fingerprinting can be applied at scale and is likely to transform future crop varietal adoption studies.
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Agricultura/métodos , Dermatoglifia del ADN/métodos , Triticum/genética , Productos Agrícolas/genética , Etiopía , Agricultores/educaciónRESUMEN
The development of genomic markers is described for Nile tilapia, Oreochromis niloticus, using the Diversity Arrays Technology (DArT) genotype-by-sequencing platform. A total of 13 215 single nucleotide polymorphism (SNP) markers and 12 490 silicoDArT (dominant) markers were identified from broodstock of two selective breeding programs [Genetically Improved Farmed Tilapia (GIFT) strain from Malaysia and the Abbassa strain from Egypt]. Over 10 000 SNPs were polymorphic in either strain, and 2985 and 3087 showed strain-specific polymorphisms for the GIFT and Abbassa strains respectively. We demonstrate the potential utility of these markers for rapid genomic screening and use in breeding programs.
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Cíclidos/genética , Genómica , Análisis de Secuencia por Matrices de Oligonucleótidos/veterinaria , Polimorfismo de Nucleótido Simple , Animales , Cruzamiento , Marcadores Genéticos , Genotipo , Análisis de Secuencia de ADN/veterinariaRESUMEN
BACKGROUND AND AIMS: Dessert and cooking bananas are vegetatively propagated crops of great importance for both the subsistence and the livelihood of people in developing countries. A wide diversity of diploid and triploid cultivars including AA, AB, AS, AT, AAA, AAB, ABB, AAS and AAT genomic constitutions exists. Within each of this genome groups, cultivars are classified into subgroups that are reported to correspond to varieties clonally derived from each other after a single sexual event. The number of those founding events at the basis of the diversity of bananas is a matter of debate. METHODS: We analysed a large panel of 575 accessions, 94 wild relatives and 481 cultivated accessions belonging to the section Musa with a set of 498 DArT markers previously developed. KEY RESULTS: DArT appeared successful and accurate to describe Musa diversity and help in the resolution of cultivated banana genome constitution and taxonomy, and highlighted discrepancies in the acknowledged classification of some accessions. This study also argues for at least two centres of domestication corresponding to South-East Asia and New Guinea, respectively. Banana domestication in New Guinea probably followed different schemes that those previously reported where hybridization underpins the emergence of edible banana. In addition, our results suggest that not all wild ancestors of bananas are known, especially in M. acuminata subspecies. We also estimate the extent of the two consecutive bottlenecks in edible bananas by evaluating the number of sexual founding events underlying our sets of edible diploids and triploids, respectively. CONCLUSIONS: The attribution of clone identity to each sample of the sets allowed the detection of subgroups represented by several sets of clones. Although morphological characterization of some of the accessions is needed to correct potentially erroneous classifications, some of the subgroups seem polyclonal.
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Genoma de Planta/genética , Musa/genética , Biodiversidad , Evolución Biológica , ADN de Plantas/genética , ADN de Plantas/aislamiento & purificación , Marcadores Genéticos/genética , Musa/clasificación , Análisis de Secuencia por Matrices de Oligonucleótidos , Fitomejoramiento , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: The functional outcome of surgically treated dislocated fractures of the distal radius is limited and does not correlate with radiographic results. Additional carpal lesions are assumed to be the cause. This study has evaluated which carpal lesions are associated with dislocated fractures of the distal radius. MATERIAL AND METHODS: A total of 104 consecutive patients with dislocated fractures of the distal radius were included in the study. The injured wrist was examined by radiography, computed tomography (CT) and magnetic resonance imaging (MRI) to determine additional carpal lesions. RESULTS: Radiographically 51 of the 104 fractures presented as type A according to the AO classification, 10 as type B and 39 as type C. The CT scan detected that only 5 of the 51 type A fractures were exclusively metaphyseal fractures. All type A fractures were associated with ligamental lesions in MRI. CONCLUSIONS: The results of the study confirm the hypothesis that every dislocated fracture of the distal radius is a combined carpal trauma associated with additional osseous and/or ligamental lesions.
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Huesos del Carpo/lesiones , Fracturas Mal Unidas/diagnóstico , Imagen por Resonancia Magnética/métodos , Traumatismo Múltiple/diagnóstico , Fracturas del Radio/diagnóstico , Tomografía Computarizada por Rayos X/métodos , Traumatismos de la Muñeca/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Huesos del Carpo/patología , Huesos del Carpo/cirugía , Femenino , Curación de Fractura , Fracturas Mal Unidas/cirugía , Humanos , Masculino , Tamizaje Masivo/métodos , Persona de Mediana Edad , Traumatismo Múltiple/cirugía , Cuidados Preoperatorios/métodos , Fracturas del Radio/cirugía , Recuperación de la Función , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Traumatismos de la Muñeca/cirugía , Adulto JovenRESUMEN
OBJECTIVE: To investigate individual changes in fetal lung volume (FLV) in fetuses with isolated congenital diaphragmatic hernia (CDH) and to calculate weekly growth rates of the FLV using serial MR examinations during pregnancy. METHODS: MR-FLV was measured in 89 fetuses with CDH. All fetuses received two MRIs. A mean weekly growth rate of the FLV was determined for each fetus and compared with the growth rate of healthy fetuses. RESULTS: Mean observed-to-expected MR-FLV (o/e MR-FLV) measured at the first MRI was 33.3 ± 12.2% and 29.5 ± 10.9% at the second MRI. In 61% of all fetuses (54/89) the o/e MR-FLV decreased during pregnancy, 26% (23/89) showed an increase in the o/e MR-FLV and 13 % (12/89) had stable values. First and last o/e MR-FLV values were significantly associated with mortality and neonatal extracorporeal membrane oxygenation (ECMO) requirement with a higher prognostic accuracy of MR-FLV measurements near delivery. Patients with CDH had lower weekly lung growth rates than healthy fetuses. There was a significant difference in the mean weekly growth rate between survivors and non-survivors and patients with and without ECMO requirement. CONCLUSION: Individual development of FLV in patients with CDH during pregnancy is extremely variable. Follow-up MR-FLV measurements are advisable before deciding upon pre- and postnatal therapeutic options. KEY POINTS: ⢠Lung development in congenital diaphragmatic hernia (CDH) during pregnancy is extremely variable. ⢠MRI demonstrates that lung growth rate is reduced in fetuses with CDH. ⢠The final observed-to-expected fetal lung volume provides the best prognostic information. ⢠Follow-up measurements are advisable before deciding upon therapeutic options.
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Anomalías Múltiples/diagnóstico , Enfermedades Fetales/diagnóstico , Hernias Diafragmáticas Congénitas , Pulmón/embriología , Imagen por Resonancia Magnética/métodos , Diagnóstico Prenatal/métodos , Anomalías Múltiples/embriología , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Hernia Diafragmática/diagnóstico , Hernia Diafragmática/embriología , Humanos , Recién Nacido , Pulmón/anomalías , Mediciones del Volumen Pulmonar , Masculino , Embarazo , Resultado del Embarazo , Pronóstico , Reproducibilidad de los Resultados , Estudios RetrospectivosRESUMEN
BACKGROUND: Bungoma District Hospital Laboratory (BDHL), which supports a 200-bed referral facility, began its Strengthening Laboratory Management Toward Accreditation (SLMTA) journey in 2011 together with eight other laboratories in the second round of SLMTA rollout in Kenya. OBJECTIVES: To describe how the SLMTA programme and enhanced quality interventions changed the culture and management style at BDHL and instilled a quality system designed to sustain progress for years to come. METHODS: SLMTA implementation followed the standard three-workshop series, mentorship site visits and audits. In order to build sustainability of progress, BDHL integrated quality improvement processes into its daily operations. The lab undertook a process of changing its internal culture to align all hospital stakeholders - including upper management, clinicians, laboratory staff and maintenance staff - to the mission of sustainable quality practices at BDHL. RESULTS: After 16 months in the SLMTA programme, BDHL improved from zero stars (38%) to four stars (89%). Over a period of two to three years, external quality assessment results improved from 47% to 87%; staff punctuality increased from 49% to 82%; clinician complaints decreased from 83% to 16; rejection rates decreased from 12% to 3%; and annual equipment repairs decreased from 40 to 15. Twelve months later the laboratory scored three stars (81%) in an external surveillance audit conducted by Kenya Accreditation Service (KENAS). CONCLUSION: Management buy-in, staff participation, use of progress-monitoring tools and feedback systems, as well as incorporation of improvement processes into routine daily activities, were vital in developing and sustaining a culture of quality improvement.
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Aegilops sharonensis (Sharon goatgrass), a diploid wheat relative, is known to be a rich source of disease resistance genes for wheat improvement. To facilitate the transfer of these genes into wheat, information on their chromosomal location is important. A genetic linkage map of Ae. sharonensis was constructed based on 179 F2 plants derived from a cross between accessions resistant (1644) and susceptible (1193) to wheat leaf rust. The linkage map was based on 389 markers (377 Diversity Arrays Technology (DArT) and 12 simple sequence repeat (SSR) loci) and was comprised of 10 linkage groups, ranging from 2.3 to 124.6 cM. The total genetic length of the map was 818.0 cM, with an average interval distance between markers of 3.63 cM. Based on the chromosomal location of 115 markers previously mapped in wheat, the four linkage groups of A, B, C, and E were assigned to Ae. sharonensis (S(sh)) and homoeologous wheat chromosomes 6, 1, 3, and 2. The single dominant gene (designated LrAeSh1644) conferring resistance to leaf rust race THBJ in accession 1644 was positioned on linkage group A (chromosome 6S(sh)) and was flanked by DArT markers wpt-9881 (at 1.9 cM distal from the gene) and wpt-6925 (4.5 cM proximal). This study clearly demonstrates the utility of DArT for genotyping uncharacterized species and tagging resistance genes where pertinent genomic information is lacking.
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Basidiomycota/patogenicidad , Mapeo Cromosómico/métodos , Cromosomas de las Plantas/genética , Genes de Plantas , Enfermedades de las Plantas/genética , Poaceae/genética , Poaceae/microbiología , Cruzamientos Genéticos , Resistencia a la Enfermedad/genética , Ligamiento Genético , Marcadores Genéticos , Genoma de Planta , Genotipo , Repeticiones de Microsatélite , Hojas de la Planta/microbiologíaRESUMEN
Since the dawn of wheat cytogenetics, chromosome 3B has been known to harbor a gene(s) that, when removed, causes chromosome desynapsis and gametic sterility. The lack of natural genetic diversity for this gene(s) has prevented any attempt to fine map and further characterize it. Here, gamma radiation treatment was used to create artificial diversity for this locus. A total of 696 radiation hybrid lines were genotyped with a custom mini array of 140 DArT markers, selected to evenly span the whole 3B chromosome. The resulting map spanned 2,852 centi Ray with a calculated resolution of 0.384 Mb. Phenotyping for the occurrence of meiotic desynapsis was conducted by measuring the level of gametic sterility as seeds produced per spikelet and pollen viability at booting. Composite interval mapping revealed a single QTL with LOD of 16.2 and r (2) of 25.6 % between markers wmc326 and wPt-8983 on the long arm of chromosome 3B. By independent analysis, the location of the QTL was confirmed to be within the deletion bin 3BL7-0.63-1.00 and to correspond to a single gene located ~1.4 Mb away from wPt-8983. The meiotic behavior of lines lacking this gene was characterized cytogenetically to reveal striking similarities with mutants for the dy locus, located on the syntenic chromosome 3 of maize. This represents the first example to date of employing radiation hybrids for QTL analysis. The success achieved by this approach provides an ideal starting point for the final cloning of this interesting gene involved in meiosis of cereals.
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Infertilidad Vegetal/genética , Infertilidad Vegetal/efectos de la radiación , Mapeo de Híbrido por Radiación , Triticum/genética , Triticum/efectos de la radiación , Cromosomas de las Plantas/genética , Variación Genética/efectos de la radiación , Genotipo , Meiosis/genética , Plantas Modificadas Genéticamente/efectos de la radiación , Semillas/genética , Semillas/efectos de la radiación , Eliminación de Secuencia/genética , Eliminación de Secuencia/efectos de la radiaciónRESUMEN
PURPOSE: To assess whether chronic lung disease (CLD) in surviving infants with congenital diaphragmatic hernia (CDH) is associated with lung hypoplasia on the basis of the results of antenatal observed-to-expected fetal lung volume (FLV) ratio measurement at magnetic resonance (MR) imaging. MATERIALS AND METHODS: The study received approval from the institutional review board, with waiver of informed consent for this retrospective review from patients who had previously given informed consent for prospective studies. The ratio of observed to expected FLV at MR imaging was calculated in 172 fetuses with CDH. At postpartum day 28, the need for supplemental oxygen implicated the diagnosis of CLD. At day 56, patients with CLD were assigned to one of three groups-those with mild, moderate, or severe CLD-according to their demand for oxygen. Logistic regression analysis was used to assess the prognostic value of the individual observed-to-expected FLV ratio for association with postnatal development of CLD. RESULTS: Children with CLD were found to have significantly smaller observed-to-expected FLV ratios at MR imaging than infants without CLD (P < .001). Grading of CLD revealed significant differences in observed-to-expected FLV ratio between patients with mild CLD and those with moderate (P = .012) or severe (P = .007) CLD. For an observed-to-expected FLV ratio of 5%, 99% of patients with CDH developed CLD, compared with less than 5% of fetuses with an observed-to-expected FLV ratio of 50%. Perinatally, development and grade of CLD were further influenced by the need for extracorporeal membrane oxygenation (ECMO) (P < .001) and gestational age at delivery (P = .009). CONCLUSION: Manifestation of CLD in surviving infants with CDH is associated with the prenatally determined observed-to-expected FLV ratio. Early neonatal therapeutic decisions can additionally be based on this ratio. Perinatally, ECMO requirement and gestational age at delivery are useful in further improving the estimated probability of CLD.
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Hernia Diafragmática/epidemiología , Hernia Diafragmática/patología , Lesión Pulmonar/epidemiología , Lesión Pulmonar/patología , Mediciones del Volumen Pulmonar , Imagen por Resonancia Magnética/estadística & datos numéricos , Diagnóstico Prenatal/métodos , Comorbilidad , Femenino , Alemania/epidemiología , Hernias Diafragmáticas Congénitas , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Prevalencia , Pronóstico , Factores de Riesgo , Sensibilidad y EspecificidadAsunto(s)
Anomalías Múltiples/diagnóstico , Arteria Femoral/anomalías , Síndrome de Kasabach-Merritt/diagnóstico , Púrpura/etiología , Sepsis/diagnóstico , Esclerosis Tuberosa/diagnóstico , Malformaciones Vasculares/diagnóstico , Diagnóstico Diferencial , Humanos , Recién Nacido , Síndrome de Kasabach-Merritt/etiología , Masculino , Esclerosis Tuberosa/complicaciones , Malformaciones Vasculares/complicacionesRESUMEN
Diversity arrays technology (DArT) genomic libraries were developed from H. chilense accessions to support robust genotyping of this species and a novel crop comprising H. chilense genome (e.g., tritordeums). Over 11,000 DArT clones were obtained using two complexity reduction methods. A subset of 2,209 DArT markers was identified on the arrays containing these clones as polymorphic between parents and segregating in a population of 92 recombinant inbred lines (RIL) developed from the cross between H. chilense accessions H1 and H7. Using the segregation data a high-density map of 1,503 cM was constructed with average inter-bin density of 2.33 cM. A subset of DArT markers was also mapped physically using a set of wheat-H. chilense chromosome addition lines. It allowed the unambiguous assignment of linkage groups to chromosomes. Four segregation distortion regions (SDRs) were found on the chromosomes 2H(ch), 3H(ch) and 5H(ch) in agreement with previous findings in barley. The new map improves the genome coverage of previous H. chilense maps. H. chilense-derived DArT markers will enable further genetic studies in ongoing projects on hybrid wheat, seed carotenoid content improvement or tritordeum breeding program. Besides, the genetic map reported here will be very useful as the basis to develop comparative genomics studies with barley and model species.
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Mapeo Cromosómico , Cromosomas de las Plantas/genética , Marcadores Genéticos/genética , Hordeum/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , ADN de Plantas/genética , Ligamiento Genético , Variación Genética , Genoma de PlantaRESUMEN
We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines 'Lynx-037DH' and 'Monty-028DH'. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.
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Brassica napus/genética , Brassica rapa/genética , Ligamiento Genético , Polimorfismo Genético , Brassica napus/clasificación , Brassica rapa/clasificación , Variaciones en el Número de Copia de ADN , Marcadores Genéticos , Genoma de Planta , Genotipo , Repeticiones de Microsatélite , FilogeniaRESUMEN
Nutritional benefits of cultivated oat (Avena sativa L., 2n = 6x = 42, AACCDD) are well recognized; however, seed protein levels are modest and resources for genetic improvement are scarce. The wild tetraploid, A. magna Murphy et Terrell (syn A. maroccana Gdgr., 2n = 4x = 28, CCDD), which contains approximately 31% seed protein, was hybridized with cultivated oat to produce a domesticated A. magna. Wild and cultivated accessions were crossed to generate a recombinant inbred line (RIL) population. Although these materials could be used to develop domesticated, high-protein oat, mapping and quantitative trait loci introgression is hindered by a near absence of genetic markers. Objectives of this study were to develop high-throughput, A. magna-specific markers; generate a genetic linkage map based on the A. magna RIL population; and map genes controlling oat domestication. A Diversity Arrays Technology (DArT) array derived from 10 A. magna genotypes was used to generate 2,688 genome-specific probes. These, with 12,672 additional oat clones, produced 2,349 polymorphic markers, including 498 (21.2%) from A. magna arrays and 1,851 (78.8%) from other Avena libraries. Linkage analysis included 974 DArT markers, 26 microsatellites, 13 SNPs, and 4 phenotypic markers, and resulted in a 14-linkage-group map. Marker-to-marker correlation coefficient analysis allowed classification of shared markers as unique or redundant, and putative linkage-group-to-genome anchoring. Results of this study provide for the first time a collection of high-throughput tetraploid oat markers and a comprehensive map of the genome, providing insights to the genome ancestry of oat and affording a resource for study of oat domestication, gene transfer, and comparative genomics.
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Avena/genética , Ligamiento Genético , Alelos , Mapeo Cromosómico/métodos , Cromosomas de las Plantas , Genes de Plantas , Técnicas Genéticas , Variación Genética , Repeticiones de Microsatélite , Modelos Genéticos , Fenotipo , Ploidias , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Análisis de Secuencia de ADN , TetraploidíaRESUMEN
A set of 90 doubled haploid (DH) lines derived from F(1) plants that originated from a cross between × Triticosecale Wittm. 'Saka3006' and ×Triticosecale Wittm. 'Modus', via wide crossing with maize, were used to create a genetic linkage map of triticale. The map has 21 linkage groups assigned to the A, B, and R genomes including 155 simple sequence repeat (SSR), 1385 diversity array technology (DArT), and 28 amplified fragment length polymorphism (AFLP) markers covering 2397 cM with a mean distance between two markers of 4.1 cM. Comparative analysis with wheat consensus maps revealed that triticale chromosomes of the A and B genomes were represented by 15 chromosomes, including combinations of 2AS.2AL#, 2AL#2BL, 6AS.6AL#, and 2BS.6AL# instead of 2A, 2B, and 6A. In respect to published maps of rye, substantial rearrangements were found also for chromosomes 1R, 2R, and 3R of the rye genome. Chromosomes 1R and 2R were truncated and the latter was linked with 3R. A nonhomogeneous distribution of markers across the triticale genome was observed with evident bias (48%) towards the rye genome. This genetic map may serve as a reference linkage map of triticale for efficient studies of structural rearrangements, gene mapping, and marker-assisted selection.
Asunto(s)
Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Mapeo Cromosómico , Grano Comestible/genética , Marcadores Genéticos/genética , Repeticiones de Microsatélite , Segregación Cromosómica/genética , Cromosomas de las Plantas/genética , Reordenamiento Génico/genética , Ligamiento Genético/genética , Genoma de Planta/genéticaRESUMEN
Pearl millet is an important component of food security in the semi-arid tropics and is assuming greater importance in the context of changing climate and increasing demand for highly nutritious food and feed. Molecular tools have been developed and applied for pearl millet on a limited scale. However, the existing tool kit needs to be strengthened further for its routine use in applied breeding programs. Here, we report enrichment of the pearl millet molecular linkage map by exploiting low-cost and high-throughput Diversity Arrays Technology (DArT) markers. Genomic representation from 95 diverse genotypes was used to develop a DArT array with circa 7,000 clones following PstI/BanII complexity reduction. This array was used to genotype a set of 24 diverse pearl millet inbreds and 574 polymorphic DArT markers were identified. The genetic relationships among the inbred lines as revealed by DArT genotyping were in complete agreement with the available pedigree data. Further, a mapping population of 140 F(7) Recombinant Inbred Lines (RILs) from cross H 77/833-2 × PRLT 2/89-33 was genotyped and an improved linkage map was constructed by integrating DArT and SSR marker data. This map contains 321 loci (258 DArTs and 63 SSRs) and spans 1148 cM with an average adjacent-marker interval length of 3.7 cM. The length of individual linkage groups (LGs) ranged from 78 cM (LG 3) to 370 cM (LG 2). This better-saturated map provides improved genome coverage and will be useful for genetic analyses of important quantitative traits. This DArT platform will also permit cost-effective background selection in marker-assisted backcrossing programs as well as facilitate comparative genomics and genome organization studies once DNA sequences of polymorphic DArT clones are available.