Datos preliminares sobre el papel del venado cola blanca Odocoileus virginianus (Artiodactyla: Cervidae) como dispersor de semillas

El papel del venado cola blanca como dispersor endozoócoro de semillas se evaluó a través de la estimación del número de semillas y especies encontradas en las muestras fecales, y el análisis del efecto del paso por el tracto digestivo sobre el porcentaje y la velocidad de germinación en semillas de una especie focal (Acacia schaffneri). En total se encontraron 369 semillas en 98 grupos de pellets. La mayoría de las semillas se apreciaban dañadas o inmaduras, sólo 67 semillas (31 morfoespecies) germinaron. El porcentaje de germinación de semillas de A. schaffneri defecadas tendió a ser mayor que la germinación de semillas control. En nuestro estudio el venado figura como depredador de semillas y ocasionalmente como dispersor de semillas. Sin embargo, nuestros resultados con animales en cautiverio muestran que el venado puede incrementar el porcentaje de germinación de algunas especies.The role of white-tailed deer in endozoochorus seed dispersal was evaluated by estimating the number of seeds and seed species found in fecal samples and assessing the effect of gut passage on germination percentage and speed for a focal seed species (Acacia schaffneri). A total of 369 seeds were found in 98 pellet groups. Most seeds appeared to be damaged or immature, and only 67 seeds (31 morphospecies) germinated. Germination percentage of defecated seeds of A. schaffneri tended to be higher than germination of control seeds. In our study site white-tailed deer appears to be acting mainly as a seed predator for ingested seeds, and occasionally as a seed disperser. Nevertheless, our results using captive animals suggest that white-tailed deer may improve seed germination of particular plant species

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality