This study reports complete plastome sequences for six species of Neotropical Cranichideae and focuses on identification of the most variable regions (hotspots) in this group of orchids. These structure of these six plastomes is relatively conserved, exhibiting lengths ranging between 142,599 to 154,562 bp with 36.7% GC on average and exhibiting typical quadripartite arrangement (LSC, SSC and two IRs). Variation detected in the LSC/IR and SSC/IR junctions is explained by the loss of ndhF and ycf1 length variation. For the two genera of epiphytic clade in Spiranthinae, almost whole sets of the ndh-gene family were missing. Eight mutation hotspots were identified based on nucleotide diversity, sequence variability and parsimony-informative sites. Three of them (rps16-trnQ, trnT-trnL, rpl32-trnL) seem to be universal hotspots in the family, and the other five (trnG-trnR, trnR-atpA, trnP-psaJ, rpl32-infA, and rps15-ycf1) are described for the first time as orchid molecular hotspots. These regions have much more variation than all those used previously in phylogenetics of the group and offer useful plastid markers for phylogenetic, barcoding and population genetic studies. The use of whole plastomes or exclusive no-gap matrices also positioned with high support the holomycotrophic Rhizanthella among Orchidoideae plastomes in model-based analyses, showing the utility of plastomes for phylogenetic placement of this unusual genus.

Background : The COVID-19 pandemic has caused significant supply shortages worldwide for SARS-CoV-2 molecular diagnosis, like RNA extraction kits. Objective : The aim of our study was to evaluate the clinical performance and analytical sensitivity of a simple SARS-CoV-2 diagnosis protocol based on heat shock without RNA extraction using both "CDC" (N gene) and "Charite" (E gene) RT-qPCR protocols. Results : 1,036 nasopharyngeal samples, 543 of them SARS-CoV-2 positive, were analyzed. The heat shock method correctly identified 68,8% (232/337) and 89.4% (202/226) SARS-CoV-2 positive samples for N gene and E gene, respectively. Analytical sensitivity was assessed for heat shock method using the CDC RT-qPCR protocol, obtaining sensitivity values of 98,6%, 93,3% and 84,8% for limit of detection of 100.000, 50.000 and 20.000 viral RNA copies/mL of sample. Conclusions : Our findings show that a simple heat shock SARS-CoV-2 RT-qPCR diagnosis method without RNA extraction is a reliable alternative for potentially infectious SARS-CoV-2 positive patients. This affordable protocol can help to overcome the cost and supply shortages for SARS-CoV-2 diagnosis, especially in developing countries. In Ecuador, it has been used already by laboratories in the public health system for more than 100.000 specimens.

On January 5 2021, Ecuadorian COVID-19 genomic surveillance program detected a suspicious case of the B.1.1.7 lineage (alpha variant) of SARS-CoV-2 in Los Rios province, later confirmed by genome sequencing. The patient travelled from the UK by the end of December 2020. By contact tracing, several new cases were detected confirming B.1.1.7 transmission and spreading in Ecuador.

Ecuador was an early COVID-19 hotspot with substantial COVID-19-mortality. In developed countries, low socioeconomic status is associated with COVID-19 infection and low compliance with non-pharmaceutical interventions (NPIs). However, if NPI were successful in resource-limited settings with high human mobility and informal labour is still unclear. We performed a retrospective observational molecular and serological study of Ecuador’s reference laboratory. We tested 1,950 respiratory samples from COVID-19 surveillance for SARS-CoV-2 and 12 respiratory viruses using RT-PCR, characterized 642 SARS-CoV-2 genomes, and examined SARS-CoV-2 seroprevalence in 1,967 samples from patients with fever in Ecuador’s reference laboratory during 2020-2021. Molecular and serological data were compared to NPI stringency in Bayesian, maximum-likelihood and modelling frameworks.SARS-CoV-2 (Pearson correlation test; r=-0.74; p=0.01) and other respiratory viruses (r=-0.68; p=0.02) detection correlated negatively with NPI stringency. SARS-CoV-2 seroprevalence increased from <1% during February-March 2020 to 50% within 6 weeks and plateaued after NPI implementation. Decrease of effective reproduction number <1 and antibody reactivity over time suggested intense SARS-CoV-2 transmission during pandemic onset, subsequently limited by NPIs. Phylogeographic analyses revealed that travel restrictions were implemented late not preventing 100 near-parallel SARS-CoV-2 introductions, and implementation of NPIs modified SARS-CoV-2 geographic spread by restricting recreational activity. NPIs stringency correlated negatively with the number of circulating SARS-CoV-2 lineages (r=-0.69; p=0.02). Virological evidence supports NPIs restricting human movement as an effective public health tool to control the spread of respiratory pathogens in resource-limited settings, providing a template for emerging SARS-CoV-2 variants and future epidemics.

Changes in telomere length are increasingly used to indicate species’ response to environmental stress across diverse taxa. Despite this broad use, few studies have explored telomere length in plants. However, rapid advances in sequencing approaches and bioinformatic tools now allow estimation of telomere length using whole genome sequencing (WGS) data. Thus, evaluation of new approaches for measuring telomere length in plants are needed. Traditionally, telomere length has been quantified using quantitative polymerase chain reaction (qPCR). While WGS has been extensively used in humans, no study to date has compared the effectiveness of WGS in estimating telomere length in plants relative to traditional qPCR approaches. In this study, we use one hundred Populus clones re-sequenced using short-read Illumina sequencing to quantify telomere length using three different bioinformatic approaches, Computel, K-seek, and TRIP, in addition to qPCR. Overall, telomere length estimates varied across different bioinformatic approaches, but were highly correlated across methods for individual genotypes. A positive correlation was observed between WGS estimates and qPCR, however, Computel estimates exhibited the greatest correlation. Computel incorporates genome coverage into telomere length calculations, suggesting that genome coverage is likely important to telomere length quantification when using WGS data. Overall, telomere estimates from WGS provided greater precision and accuracy of telomere length estimates relative to qPCR. The findings suggest WGS is a promising approach for assessing telomere length, and as the field of telomere ecology evolves may provide added value to assaying response to biotic and abiotic environments for plants needed to accelerate plant breeding and conservation management.