263 research outputs found

    A small XY chromosomal region explains sex determination in wild dioecious V. vinifera and the reversal to hermaphroditism in domesticated grapevines

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    Publis014-agap-029Background In Vitis vinifera L., domestication induced a dramatic change in flower morphology: the wild sylvestris subspecies is dioecious while hermaphroditism is largely predominant in the domesticated subsp. V. v. vinifera. The characterisation of polymorphisms in genes underlying the sex-determining chromosomal region may help clarify the history of domestication in grapevine and the evolution of sex chromosomes in plants. In the genus Vitis, sex determination is putatively controlled by one major locus with three alleles, male M, hermaphrodite H and female F, with an allelic dominance M > H > F. Previous genetic studies located the sex locus on chromosome 2. We used DNA polymorphisms of geographically diverse V. vinifera genotypes to confirm the position of this locus, to characterise the genetic diversity and traces of selection in candidate genes, and to explore the origin of hermaphroditism. Results In V. v. sylvestris, a sex-determining region of 154.8 kb, also present in other Vitis species, spans less than 1% of chromosome 2. It displays haplotype diversity, linkage disequilibrium and differentiation that typically correspond to a small XY sex-determining region with XY males and XX females. In male alleles, traces of purifying selection were found for a trehalose phosphatase, an exostosin and a WRKY transcription factor, with strikingly low polymorphism levels between distant geographic regions. Both diversity and network analysis revealed that H alleles are more closely related to M than to F alleles. Conclusions Hermaphrodite alleles appear to derive from male alleles of wild grapevines, with successive recombination events allowing import of diversity from the X into the Y chromosomal region and slowing down the expansion of the region into a full heteromorphic chromosome. Our data are consistent with multiple domestication events and show traces of introgression from other Asian Vitis species into the cultivated grapevine gene pool. La vigne domestiquée, Vitis vinifera ssp. vinifera, cultivée pour la production de fruit et de vin à travers le monde, dérive de la vigne sauvage, Vitis vinifera ssp. sylvestris, sous-espèce endémique de l'Eurasie. Au cours de la domestication, le système de reproduction a évolué de la diécie à l'hermaphrodisme. Nous montrons que la région du sexe est sous le contrôle d'une région chromosomique qui couvre au maximum 154kpbp, moins de 1% du chromosome 2. La caractérisation de ce locus en terme de diversité haplotypique, de signature de sélection et de déséquilibre de liaison a permis de révéler un système de détermination sexuelle de type XY. La petite taille de cette région chromosomique semble indiquer un stade très précoce dans l'évolution de chromosomes sexuels, malgré que la diécie soit le trait ancestral chez toutes les espèces de Vitis, ayant divergé du sous-genre Muscadinia il y a plusieurs millions d'années. L'analyse des distances génétiques entre haplotypes dans le locus du sexe a révélé que l'hermaphrodisme observé chez la vigne domestiquée résulte de la mutation de l'allèle mâle présent chez la vigne sauvage. Le réseau d'haplotypes a montré qu'en plus de la contribution de V. sylvestris, une autre espèce de Vitis asiatique a pu contribuer à la constitution du génome actuel de la vigne cultivée moderne. Ces travaux résultent d'une collaboration entre l'équipe DAAV d'AGAP et l'UMR CBAE (Montpellier)

    The discovery of wild date palms in oman reveals a complex domestication history involving centers in the middle east and africa

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    For many crops, wild relatives constitute an extraordinary resource for cultivar improvement [1, 2] and also help to better understand the history of their domestication [3]. However, the wild ancestor species of several perennial crops have not yet been identified. Perennial crops generally present a weak domestication syndrome allowing cultivated individuals to establish feral populations difficult to distinguish from truly wild populations, and there is frequently ongoing gene flow between wild relatives and the crop that might erode most genetic differences [4]. Here we report the discovery of populations of the wild ancestor species of the date palm (Phoenix dactylifera L.), one of the oldest and most important cultivated fruit plants in hot and arid regions of the Old World. We discovered these wild individuals in remote and isolated mountainous locations of Oman. They are genetically more diverse than and distinct from a representative sample of Middle Eastern cultivated date palms and exhibit rounded seed shapes resembling those of a close sister species and archeological samples, but not modern cultivars. Whole-genome sequencing of several wild and cultivated individuals revealed a complex domestication history involving the contribution of at least two wild sources to African cultivated date palms. The discovery of wild date palms offers a unique chance to further elucidate the history of this iconic crop that has constituted the cornerstone of traditional oasis polyculture systems for several thousand years [5]

    Leveraging the potential of charred archaeological seeds for reconstructing the history of date palm

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    The analysis of seeds from archaeobotanical assemblages is essential for understanding the history of crop cultivation. However, the majority of these seeds are typically found charred, a condition that not only degrades DNA, which hinders genetic studies, but also distorts their morphological features, which may bias comparisons with uncharred modern samples. While the effects of charring on several other crop seeds or fruits are well- documented, date palm seeds remain largely unexamined, limiting our ability to use charred seeds effectively to document the agrobiodiversity dynamic of this crop. In this study, we assessed the morphological changes induced by the charring of 1375 Phoenix seeds under varied conditions, including charring temperatures of 200–600 ◦ C, exposure durations from 10 to 120 min, and oxidizing/reducing conditions. By comparing charred samples with a modern reference collection of 6991 seeds, we evaluated the extent to which charring affects the ability to discriminate between groups of interest, particularly between wild and domesticated specimens. Our study identified a significant shrinkage in Phoenix seeds, up to 25%, as a result of charring, with the extent of deformation influenced by the conditions of exposure. The shrinkage displayed an isometric pattern, keeping the proportions between seed dimensions consistent, thereby validating size ratios as a dependable metric for studying Phoenix agrobiodiversity even when dealing with charred material. Moreover, seed outlines stay pre- dominantly unchanged, further endorsing their utility in morphometric studies. Using our results to examine 13 charred seeds from Shahi Tump and Miri Qalat, two Protohistoric settlements (5th-3rd millennia BCE) located in the Kech-Makran district of southwestern Pakistan, we deduced a predominance of wild resource utilization over the cultivation of date palms. This research sheds light on the impact of charring on seed morphology and underscores its potential in differentiating between species and groups. It moreover confirms the value of charred seeds as a crucial resource for unraveling the complex history of crop cultivation, offering a detailed framework for future studies in this domain

    L'intégration de l'ethnobotanique et de la génétique des populations met en évidence l'agrobiodiversité des palmiers dattiers de l'oasis de Siwa (Égypte) et leur importance pour l'histoire évolutive de l'espèce.

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    Crop diversity is shaped by biological and social processes interacting at different spatiotemporal scales. Here we combined population genetics and ethnobotany to investigate date palm (Phoenix dactylifera L.) diversity in Siwa Oasis, Egypt. Based on interviews with farmers and observation of practices in the field, we collected 149 date palms from Siwa Oasis and 27 uncultivated date palms from abandoned oases in the surrounding desert. Using genotyping data from 18 nuclear and plastid microsatellite loci, we confirmed that some named types each constitute a clonal line, i.e. a true-to-type cultivar. We also found that others are collections of clonal lines, i.e. ethnovarieties, or even unrelated samples, i.e. local categories. This alters current assessments of agrobiodiversity, which are visibly underestimated, and uncovers the impact of low-intensity, but highly effective, farming practices on biodiversity. These hardly observable practices, hypothesized by ethnographic survey and confirmed by genetic analysis, are enabled by the way Isiwans conceive and classify living beings in their oasis, which do not quite match the way biologists do: a classic disparity of etic vs. emic categorizations. In addition, we established that Siwa date palms represent a unique and highly diverse genetic cluster, rather than a subset of North African and Middle Eastern palm diversity. As previously shown, North African date palms display evidence of introgression by the wild relative Phoenix theophrasti, and we found that the uncultivated date palms from the abandoned oases share even more alleles with this species than cultivated palms in this region. The study of Siwa date palms could hence be a key to the understanding of date palm diversification in North Africa. Integration of ethnography and population genetics promoted the understanding of the interplay between diversity management in the oasis (short-time scale), and the origins and dynamic of diversity through domestication and diversification (long-time scale)

    Rheumatoid arthritis - treatment: 180. Utility of Body Weight Classified Low-Dose Leflunomide in Japanese Rheumatoid Arthritis

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    Background: In Japan, more than 20 rheumatoid arthritis (RA) patients died of interstitial pneumonia (IP) caused by leflunomide (LEF) were reported, but many of them were considered as the victims of opportunistic infection currently. In this paper, efficacy and safety of low-dose LEF classified by body weight (BW) were studied. Methods: Fifty-nine RA patients were started to administrate LEF from July 2007 to July 2009. Among them, 25 patients were excluded because of the combination with tacrolimus, and medication modification within 3 months before LEF. Remaining 34 RA patients administered 20 to 50 mg/week of LEF were followed up for 1 year and enrolled in this study. Dose of LEF was classified by BW (50 mg/week for over 50 kg, 40 mg/week for 40 to 50 kg and 20 to 30 mg/week for under 40 kg). The average age and RA duration of enrolled patients were 55.5 years old and 10.2 years. Prednisolone (PSL), methotrexate (MTX) and etanercept were used in 23, 28 and 2 patients, respectively. In case of insufficient response or adverse effect, dosage change or discontinuance of LEF were considered. Failure was defined as dosages up of PSL and MTX, or dosages down or discontinuance of LEF. Last observation carried forward method was used for the evaluation of failed patients at 1 year. Results: At 1 year after LEF start, good/ moderate/ no response assessed by the European League Against Rheumatism (EULAR) response criteria using Disease Activity Score, including a 28-joint count (DAS28)-C reactive protein (CRP) were showed in 14/ 10/ 10 patients, respectively. The dosage changes of LEF at 1 year were dosage up: 10, same dosage: 5, dosage down: 8 and discontinuance: 11 patients. The survival rate of patients in this study was 23.5% (24 patients failed) but actual LEF continuous rate was 67.6% (11 patients discontinued) at 1 year. The major reason of failure was liver dysfunction, and pneumocystis pneumonia was occurred in 1 patient resulted in full recovery. One patient died of sepsis caused by decubitus ulcer infection. DAS28-CRP score was decreased from 3.9 to 2.7 significantly. Although CRP was decreased from 1.50 to 0.93 mg/dl, it wasn't significant. Matrix metalloproteinase (MMP)-3 was decreased from 220.0 to 174.2 ng/ml significantly. Glutamate pyruvate transaminase (GPT) was increased from 19 to 35 U/l and number of leukocyte was decreased from 7832 to 6271 significantly. DAS28-CRP, CRP, and MMP-3 were improved significantly with MTX, although they weren't without MTX. Increase of GPT and leukopenia were seen significantly with MTX, although they weren't without MTX. Conclusions: It was reported that the risks of IP caused by LEF in Japanese RA patients were past IP history, loading dose administration and low BW. Addition of low-dose LEF is a potent safe alternative for the patients showing unsatisfactory response to current medicines, but need to pay attention for liver function and infection caused by leukopenia, especially with MTX. Disclosure statement: The authors have declared no conflicts of interes

    Genomics and morphometry of herbarium specimens elucidate the origin of the Cape Verde date palm (Phoenix atlantica A.Chev.) and highlight its agronomic potential

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    Societal Impact Statement: As climate change accelerates, breeding resilient crops is urgent. The date palm (Phoenix dactylifera L.), a crucial 18 billion USD fruit crop, underpins North African and West Asian oasis agroecosystems. This study investigates the genetics and morphology of its closest wild relative, the endemic and endangered Cape Verde date palm (Phoenix atlantica A.Chev.). We reveal that the latter originated through a feralisation process from domesticated date palms, evolving back into a wild state with unique genetic diversity. This highlights the need to protect its distinctiveness and opens the possibility of enhancing date palm resilience through its inclusion in breeding programs. Summary: The date palm (Phoenix dactylifera L.). is a major crop but its sustainability is threatened by climate change. This challenge could be mitigated by breeding with wild relatives or feral populations. The endangered and endemic Cape Verde date palm (Phoenix atlantica A.Chev.) is thought to be among the closest relatives of the date palm, but its origin and taxonomic status remain unclear, with studies having recovered it either as a separate species or a feral date palm. Better understanding the differentiation of P. atlantica and P. dactylifera is needed to fully unlock the potential of the Cape Verde date palm as a candidate for date palm improvement. In this study, we employ an integrative approach to clarify the origin of P. atlantica. Specifically, we investigate the phylogenetic placement, genetic structure, and seed morphology of P. atlantica by generating extensive genomic and seed morphology datasets from expert-verified historical and modern specimens of Phoenix, including the type specimen of P. atlantica. Our findings indicate that P. atlantica is monophyletic but nested within P. dactylifera. Its genetic diversity overlaps substantially but not completely with North African date palm varieties, and its seeds share characteristics with those of cultivated and feral date palms, notably elongation, a trait linked to domestication. These results suggest that P. atlantica may be an incipient species that originated from a date palm feralisation event. We emphasise the need for conserving its natural genetic variation and the traditional knowledge associated with its name to support breeding programs

    The Egyptian olive (<i>Olea europaea</i>subsp.<i>europaea</i>) in the later first millennium BC: origins and history using the morphometric analysis of olive stones

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    The authors examine a sample of olive stones from Egyptian contexts and show that from the first millennium BC, if not before, some of them relate to cultivars originating from the Levant. But equally prominent and just as early is another variety, of unknown origin and currently peculiar to Egypt. The method used is geometrical morphometric analysis – essentially classifying the olive stones by their shape.</jats:p

    Comparison of image acquisition techniques and morphometric methods to distinguish between Vitis vinifera subspecies and cultivars

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    International audienceFor decades, it has been known that the morphology of wild Vitis vinifera (grape) pips differ from domesticated ones. Based on these differences, computerised image analysis and morphometrics allow us to obtain excellent results to identify the domestication status of archaeological grape pips. However, various image analysis methodologies and morphometric methods have been applied in previous studies for this purpose. Our study has examined, for the first time, the different techniques of digital image acquisition (digital camera vs. scanner) of grape pips, with the aim of testing the identification performance using both traditional and geometric morphometric features to distinguish wild from domestic grape pips. The performance of different morphometric methods established that all image acquisition techniques and morphometric methods correctly distinguished between wild and domestic grapes. The use of the combined geometric morphometric features of both dorsal and lateral views of the pips provided the best accuracy in distinguishing individual cultivars

    Origins and insights into the historic Judean date palm based on genetic analysis of germinated ancient seeds and morphometric studies

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    Germination of 2000-year-old seeds of Phoenix dactylifera from Judean desert archaeological sites provides a unique opportunity to study the Judean date palm, described in antiquity for the quality, size, and medicinal properties of its fruit, but lost for centuries. Microsatellite genotyping of germinated seeds indicates that exchanges of genetic material occurred between the Middle East (eastern) and North Africa (western) date palm gene pools, with older seeds exhibiting a more eastern nuclear genome on a gradient from east to west of genetic contributions. Ancient seeds were significantly longer and wider than modern varieties, supporting historical records of the large size of the Judean date. These findings, in accord with the region’s location between east and west date palm gene pools, suggest that sophisticated agricultural practices may have contributed to the Judean date’s historical reputation. Given its exceptional storage potentialities, the date palm is a remarkable model for seed longevity research
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