The repeatome is composed of diverse families of repetitive DNA that keep signatures on the historical events that shaped the evolution of their hosting species. The cold seasonal Loliinae subtribe ...includes worldwide distributed taxa, some of which are the most important forage and lawn species (fescues and ray-grasses). The Loliinae are prone to hybridization and polyploidization. It has been observed a striking two-fold difference in genome size between the broad-leaved (BL) and fine-leaved (FL) Loliinae diploids and a general trend of genome reduction of some high polyploids. We have used genome skimming data to uncover the composition, abundance, and potential phylogenetic signal of repetitive elements across 47 representatives of the main Loliinae lineages. Independent and comparative analyses of repetitive sequences and of 5S rDNA loci were performed for all taxa under study and for four evolutionary Loliinae groups Loliinae, Broad-leaved (BL), Fine-leaved (FL), and Schedonorus lineages. Our data showed that the proportion of the genome covered by the repeatome in the Loliinae species was relatively high (average ∼ 51.8%), ranging from high percentages in some diploids (68.7%) to low percentages in some high-polyploids (30.7%), and that changes in their genome sizes were likely caused by gains or losses in their repeat elements. Ty3-gypsy Retand and Ty1-copia Angela retrotransposons were the most frequent repeat families in the Loliinae although the relatively more conservative Angela repeats presented the highest correlation of repeat content with genome size variation and the highest phylogenetic signal of the whole repeatome. By contrast, Athila retrotransposons presented evidence of recent proliferations almost exclusively in the
Lolium
clade. The repeatome evolutionary networks showed an overall topological congruence with the nuclear 35S rDNA phylogeny and a geographic-based structure for some lineages. The evolution of the Loliinae repeatome suggests a plausible scenario of recurrent allopolyploidizations followed by diploidizations that generated the large genome sizes of BL diploids as well as large genomic rearrangements in highly hybridogenous lineages that caused massive repeatome and genome contractions in the Schedonorus and Aulaxyper polyploids. Our study has contributed to disentangling the impact of the repeatome dynamics on the genome diversification and evolution of the Loliinae grasses.
Oceanic islands constitute natural laboratories to study plant speciation and biogeographic patterns of island endemics. Juan Fernandez is a southern Pacific archipelago consisting of three small ...oceanic islands located 600-700 km west of the Chilean coastline. Exposed to current cold seasonal oceanic climate, these 5.8-1 Ma old islands harbor a remarkable endemic flora. All known Fernandezian endemic grass species belong to two genera,
and
, of uncertain taxonomic adscription. Classical and modern classifications have placed them either in Bromeae (
), Duthieinae, Aveneae/Poeae, or Loliinae (fine-leaved
); however, none of them have clarified their evolutionary relationships with respect to their closest
relatives.
includes four species, which are endemic to Masatierra (Robinson Crusoe island) (
and
) and to Masafuera (Alejandro Selkirk island) (
and
). The monotypic
is a rare endemic species to Masatierra which is only known from its type locality and is currently considered extinct. We have used museomic approaches to uncover the challenging evolutionary history of these endemic grasses and to infer the divergence and dispersal patterns from their ancestors. Genome skimming data were produced from herbarium samples of
and
, and the 164 years old type specimen of
, as well as for a collection of 33 species representing the main broad- and fine-leaved Loliinae lineages. Paired-end reads were successfully mapped to plastomes and nuclear ribosomal cistrons of reference
species and used to reconstruct phylogenetic trees. Filtered ITS and
TLF sequences from these genomes were further combined with our large Loliinae data sets for accurate biogeographic reconstruction. Nuclear and plastome data recovered a strongly supported fine-leaved Fernandezian clade where
was resolved as sister to
. Bayesian divergence dating and dispersal-extinction-cladogenesis range evolution analyses estimated the split of the Fernandezian clade from its ancestral southern American Pampas-Ventanian Loliinae lineage in the Miocene-Pliocene transition, following a long distance dispersal from the continent to the uplifted volcanic palaeo-island of Santa Clara-Masatierra. Consecutive Pliocene-Pleistocene splits and a Masatierra-to-Masafuera dispersal paved the way for
speciation of
and
taxa.
One major goal in plant evolutionary ecology is to address how and why tritrophic interactions mediated by phytochemical plant defences vary across species, space, and time. In this study, we tested ...three classical hypotheses about plant defences: (i) the resource-availability hypothesis, (ii) the altitudinal/elevational gradient hypothesis and (iii) the defence escalation hypothesis. For this purpose, predatory soil nematodes were challenged to hunt for root herbivores based on volatile cues from damaged or intact roots of 18 Alpine Festuca grass species adapted to distinct climatic niches spanning 2000 meters of elevation. We found that adaptation into harsh, nutrient-limited alpine environments coincided with the production of specific blends of volatiles, highly attractive for nematodes. We also found that recently-diverged taxa exposed to herbivores released higher amounts of volatiles than ancestrally-diverged species. Therefore, our model provides evidence that belowground indirect plant defences associated with tritrophic interactions have evolved under two classical hypotheses in plant ecology. While phylogenetic drivers of volatile emissions point to the defence-escalation hypothesis, plant local adaptation of indirect defences is in line with the resource availability hypothesis.
Allopolyploidy is considered a driver of diversity in subtribe Loliinae. We investigate the evolution and systematics of the poorly studied Mesoamerican and South American polyploid broad-leaved ...Festuca L. species of uncertain origin and unclear taxonomy. A taxonomic study of seven diagnostic morphological traits was conducted on a representation of 22 species. Phylogenomic analyses were performed on a representation of these supraspecific taxa and all other Loliinae lineages using separate data from the entire plastome, nuclear rDNA 45S and 5S genes, and repetitive DNA elements. F. subgen. Mallopetalon falls within the fine-leaved (FL) Loliinae clade, whereas the remaining taxa are nested within the broad-leaved (BL) Loliinae clade forming two separate Mexico–Central–South American (MCSAI, MCSAII) lineages. MCSAI includes representatives of F. sect. Glabricarpae and F. subgen. Asperifolia plus F. superba, and MCSAII of F. subgen. Erosiflorae and F. sect. Ruprechtia plus F. argentina. MCSAII likely had a BL Leucopoa paternal ancestor, MCSAI and MCSAII a BL Meso-South American maternal ancestor, and Mallopetalon FL, American I–II ancestors. Plastome vs. nuclear topological discordances corroborated the hybrid allopolyploid origins of these taxa, some of which probably originated from Northern Hemisphere ancestors. The observed data indicate rapid reticulate radiations in the Central–South American subcontinent. Our systematic study supports the reclassification of some studied taxa in different supraspecific Festuca ranks.
Locomotion speed changes appear following hippocampal injury. We used a hippocampal penetrating brain injury mouse model to analyze other kinematic changes. We found a significant decrease in ...locomotion speed in both the open field and tunnel walk tests. We described a new quantitative method that allows us to analyze and compare the displacement curves between mice steps. In the tunnel walk, we marked mice with indelible ink on the knee, ankle, and metatarsus of the left and right hindlimbs to evaluate both in every step. Animals with hippocampal damage exhibit slower locomotion speed in both hindlimbs. In contrast, in the cortical injured group, we observed significant speed decrease only in the right hindlimb. We found changes in the displacement patterns after hippocampal injury. Mesenchymal stem cells-derived extracellular vesicles had been used for the treatment of several diseases in animal models. This study evaluated the effects of intranasal administration of endometrial mesenchymal stem cells-derived extracellular vesicles on the outcome after the hippocampal injury. We report the presence of VEGF, GM-CSF, and IL-6 in these vesicles. We observed locomotion speed and displacement pattern preservation in mice after vesicle treatment. These mice had lower pyknotic cells percentage and a smaller damaged area in comparison with the non-treated group, probably due to angiogenesis, wound repair, and inflammation decrease. Our results build upon the evidence of the hippocampal role in walk control and suggest that the extracellular vesicles confer neuroprotection to the damaged hippocampus.
Allopolyploidy is considered a driver of diversity in subtribe Loliinae. We investigate the evolution and systematics of the poorly studied Mesoamerican and South American polyploid broad-leaved ...Festuca L. species of uncertain origin and unclear taxonomy. A taxonomic study of seven diagnostic morphological traits was conducted on a representation of 22 species. Phylogenomic analyses were performed on a representation of these supraspecific taxa and all other Loliinae lineages using separate data from the entire plastome, nuclear rDNA 45S and 5S genes, and repetitive DNA elements. F. subgen. Mallopetalon falls within the fine-leaved (FL) Loliinae clade, whereas the remaining taxa are nested within the broad-leaved (BL) Loliinae clade forming two separate Mexico–Central–South American (MCSAI, MCSAII) lineages. MCSAI includes representatives of F. sect. Glabricarpae and F. subgen. Asperifolia plus F. superba, and MCSAII of F. subgen. Erosiflorae and F. sect. Ruprechtia plus F. argentina. MCSAII likely had a BL Leucopoa paternal ancestor, MCSAI and MCSAII a BL Meso-South American maternal ancestor, and Mallopetalon FL, American I–II ancestors. Plastome vs. nuclear topological discordances corroborated the hybrid allopolyploid origins of these taxa, some of which probably originated from Northern Hemisphere ancestors. The observed data indicate rapid reticulate radiations in the Central–South American subcontinent. Our systematic study supports the reclassification of some studied taxa in different supraspecific Festuca ranks.
Diabetic peripheral neuropathy (DPN) is the most common complication of type 2 diabetes mellitus (T2DM); its diagnosis and treatment are based on symptomatic improvement. However, as pharmacological ...therapy causes multiple adverse effects, the implementation of acupunctural techniques, such as electroacupuncture (EA) has been suggested as an alternative treatment. Nonetheless, there is a lack of scientific evidence, and its mechanisms are still unclear. We present the design and methodology of a new clinical randomized trial, that investigates the effectiveness of EA for the treatment of DPN.
This study is a four-armed, randomized, controlled, multicenter clinical trial (20-week intervention period, plus 12 weeks of follow-up after concluding intervention). A total of 48 T2DM patients with clinical signs and symptoms of DPN; and electrophysiological signs in the Nerve Conduction Study (NCS); will be treated by acupuncture specialists in outpatient units in Mexico City. Patients will be randomized in a 1:1 ratio to one of the following four groups: (a) short fibre DPN with EA, (b) short fibre DPN with sham EA, (c) axonal DPN with EA and (d) axonal DPN with sham EA treatment. The intervention will consist of 32 sessions, 20 min each, per patient over two cycles of intervention of 8 weeks each and a mid-term rest period of 4 weeks. The primary outcome will be NCS parameters, and secondary outcomes will include DPN-related symptoms and pain by Michigan Neuropathy Screening Instrument (MNSI), Michigan Diabetic Neuropathy Score (MDNS), Dolour Neuropatique Score (DN-4), Semmes-Westein monofilament, Numerical Rating Scale (NRS) for pain assessment, and the 36-item Short Form Health Survey (SF-36). To measure quality of life and improve oxidative stress, the inflammatory response; and genetic expression; will be analysed at the beginning and at the end of treatment.
This study will be conducted to compare the efficacy of EA versus sham EA combined with conventional diabetic and neuropathic treatments if needed. EA may improve NCS, neuropathic pain and symptoms, oxidative stress, inflammatory response, and genetic expression, and it could be considered a potential coadjutant treatment for the management of DPN with a possible remyelinating effect.
ClinicalTrials.gov. NCT05521737 Registered on 30 August 2022. International Clinical Trials Registry Platform (ICTRP) ISRCTN97391213 Registered on 26 September 2022 2b.
To describe the primary cancer sites and clinical features of choroidal metastasis in Mexican patients.
This was a retrospective, observational, and multi-center study. Data were recollected from 6 ...ophthalmological hospitals in Mexico from patients with choroidal metastasis diagnosed from 2000 to 2018.
Seventy-eight patients were studied: 43 were female and 35 were male. Mean age at presentation was 57.6 years. Overall, primary cancer sites were: 1) breast: 27 cases (34.6%); 2) lung: 19 cases (24.3%); 3) unknown: 8 cases (10.2%); 4) gastrointestinal: 7 cases (8.9%); 5) renal: 5 cases (6.4%); 6) testicular: 3 cases (3.8%); 7) ovary: 3 Cases (3.8%); 8) prostate: 2 cases (2.5%); 9) thyroid: 2 cases (2.5%); 10) carcinoid: 1 case (1.2%); and 11) multiple myeloma: 1 case (1.2%). Divided by gender, for women, the main three sites were: breast, unknown, and ovary. For men, the main three sites were: lung, gastrointestinal, and testicular. Oldest cases were breast cancer (87 and 85 years); youngest cases were testicular (23 and 25 years). Solitary lesions were observed in 56 cases (71.7%); multiple lesions were observed in 22 cases (28.2%). Forty-two cases had a white or yellowish color, while 6 cases presented an orange color.
Primary cancer sites and clinical features of choroidal metastasis in Mexican patients show important differences from other populations previously studied, mainly the presence of a higher proportion of gastrointestinal and renal cancer, as well as higher incidence of ovarian and testicular cancer. These types of cancer, although not as common as breast or lung, need to be taken into account when studying Mexican patients living abroad.
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