Biology subjects

Flores, B.

Publications and source records attributed to Flores, B..

2 recordsLinked to original sources

bioRxiv2025

Population structure of Phytophthora infestans collected from potatoes in Guatemala and Honduras

Phytophthora infestans, the causal agent of late blight, remains a major constraint to potato production worldwide. In Central America, particularly in Guatemala and Honduras, information on the pathogen's population structure is limited despite its economic importance and reliance on imported seed potatoes. This study characterized the population structure of P. infestans in potato fields in Guatemala and Honduras using microsatellite markers, mitochondrial haplotypes, and mating type analyses. Four SSR-defined groups were identified, three corresponding to the previously described clonal lineages EU13A2, NI_1, and US8A2, and one putative group designated CeA (Central America). The detection of EU13A2, a lineage first reported in Europe and subsequently in Asia, indicates its establishment in Central America. All successfully characterized isolates exhibited the Ia mitochondrial haplotype, indicating limited mitochondrial diversity despite substantial nuclear SSR variation. AMOVA revealed significant genetic differentiation between Honduras and Guatemala, accounting for 24.43% of the total SSR variation (p = 0.022). Significant linkage disequilibrium was detected within the analyzed populations. The occurrence of genetically distinct P. infestans groups across the study area highlights the importance of monitoring transboundary pathogen movement in Central America.

pathology↗

bioRxiv2020

A Rare Deletion in SARS-CoV-2 ORF6 Dramatically Alters the Predicted Three-Dimensional Structure of the Resultant Protein

The function of the SARS-CoV-2 accessory protein p6, encoded by ORF6, is not fully known. Based upon its similarity to p6 from SARS-CoV, it may play a similar role, namely as an antagonist of type I interferon (IFN) signaling. Here we report the sequencing of a SARS-CoV-2 strain passaged six times after original isolation from a clinical patient in Hong Kong. The genome sequence shows a 27 nt in-frame deletion ({Delta}27,264-27,290) within ORF6, predicted to result in a 9 aa deletion ({Delta}FKVSIWNLD) from the central portion of p6. This deletion is predicted to result in a dramatic alteration in the three-dimensional structure of the resultant protein (p6{Delta}22-30), possibly with significant functional implications. Analysis of the original clinical sample indicates that the deletion was not present, while sequencing of subsequent passages of the strain identifies the deletion as a majority variant. This suggests that the deletion originated ab initio during passaging and subsequently propagated into the majority, possibly due to the removal of selective pressure through the IFN-deficient Vero E6 cell line. The specific function of the SARS-CoV-2 p6 N-terminus, if any, has not yet been determined. However, this deletion is predicted to cause a shift from N-endo to N-ecto in the transmembrane localization of the SARS-CoV-2 p6{Delta}22-30 N-terminus, possibly leading to the ablation of its native function.

genomics↗