Biology subjects

Torres, G. A.

Publications and source records attributed to Torres, G. A..

2 recordsLinked to original sources

bioRxiv2025

Cenchrus purpureus and Cenchrus americanus repeatome provide chromosomal markers to distinguish subgenomes

Cenchrus L. is an important genus within the Poaceae family, comprising several species of high agronomic significance, such as Cenchrus purpureus and Cenchrus americanus, for production of forage and grains, respectively. Cenchrus americanus is a diploid species (2n = 2x = 14, AA genome), while Cenchrus purpureus is an allotetraploid (2n = 4x = 28, AABB genome). The A subgenome is believed to be homeologous to and possibly derived from the A subgenome, while the origin of the B subgenome remains undefined. Despite their distinct subgenomic compositions, both species exhibit a high level of genome homology. The objective of the present work was the in silico characterization and comparative analysis of the repetitive fraction of the genomes of Cenchrus purpureus and Cenchrus americanus using genome skimming and a graph-based clustering approach, as well as the in situ hybridization of specific satellite DNA clusters into the chromosomes of both species. The repetitive fraction of the genome of C. purpureus and C. americanus corresponds to 52.23% and 76.82%, respectively. The most abundant repetitive elements in both species are the LTR retrotransposons. Satellite DNA sequences correspond to 2.55% and 4.17% of the genome of each species, respectively. Four new satellite sequences were identified as subgenome-specific sequences for both species, along with new centromeric variants. The ancestral relationship and the polyploidization-diploidization cycles played a fundamental role in the composition of their repetitive fraction. These cycles led Cenchrus americanus, a possible paleopolyploid, to a greater abundance of transposable elements compared to Cenchrus purpureus, a recent allopolyploid.

genomics↗

bioRxiv2021

Comparing Expression of OAS-RNaseL Pathway-Related Genes in SARS-CoV-2 and Similar Viruses

The COVID-19 pandemic, caused by the virus SARS-CoV-2, has been a major public health emergency and has caused millions of deaths worldwide to date. Due to the novel nature of the virus, efforts across the world are underway to better understand the molecular pathogenesis of SARS-CoV-2 and how it interacts with host immune responses. One important branch of the innate immune response, the interferon system, triggers the expression of many effector mechanisms known to be powerful antagonists against many pathogenic viruses. One such interferon stimulated mechanism is the OAS-RNaseL pathway, which is known to trigger the degradation of viral RNA in infected host cells. Our study seeks to utilize publicly available transcriptomic data to analyze the host cell OAS-RNaseL pathway to SARS-CoV-2 infection. We hoped to gain an understanding of the importance of the pathway in controlling SARS-CoV-2 infection and whether or not the pathway could be exploited therapeutically. Our findings demonstrated that upregulation of OAS-RNaseL pathway genes in response to SARS-CoV-2 infection varies based on cell type and appeared to correlate with ACE2 receptor expression. Pathway responses to other viruses like SARS-CoV and MERS-CoV were found to parallel those to SARS-CoV-2, suggesting common response patterns by the pathway to these viruses. Overall, these results demonstrate that the OAS-RNaseL pathway could contribute to control of SARS-CoV-2 infection. Further studies on various mechanistic actions by the pathway would need to be conducted to fully understand its role in host defense and therapy.

immunology↗