Cot-based sequence discovery represents a powerful means by which both low-copy and repetitive sequences can be selectively and efficiently fractionated, cloned, and characterized. Based upon the results of a Cot analysis, hydroxyapatite chromatography was used to fractionate sorghum (Sorghum bicolor) genomic DNA into highly repetitive (HR), moderately repetitive (MR), and single/low-copy (SL) sequence components that were consequently cloned to produce HRCot, MRCot, and SLCot genomic libraries. Filter hybridization (blotting) and sequence analysis both show that the HRCot library is enriched in sequences traditionally found in high-copy number (e.g., retroelements, rDNA, centromeric repeats), the SLCot library is enriched in low-copy sequences (e.g., genes and “nonrepetitive ESTs”), and the MRCot library contains sequences of moderate redundancy. The Cot analysis suggests that the sorghum genome is approximately 700 Mb (in agreement with previous estimates) and that HR, MR, and SL components comprise 15%, 41%, and 24% of sorghum DNA, respectively. Unlike previously described techniques to sequence the low-copy components of genomes, sequencing of Cot components is independent of expression and methylation patterns that vary widely among DNA elements, developmental stages, and taxa. High-throughput sequencing of Cot clones may be a means of “capturing” the sequence complexity of eukaryotic genomes at unprecedented efficiency

A SARS-CoV-2 surrogate virus neutralization test based on antibody-mediated blockage of ACE2-spike proteinprotein interaction.

No abstract

word count 48 11 Chickens, turkeys, ducks, quail and geese were challenged with SARS-CoV-2 or MERS-12 CoV. No disease was observed, no virus replication was detected, and antibodies were not 13 detected in serum. Neither virus replicated in embryonating chicken's eggs. Poultry are unlikely 14 to serve a role in the maintenance of either virus. 15 Text-word count 766 16 Coronaviruses (CoV) of animals periodically transmit to humans (1) as recently occurred with 17 SARS-CoV-2. SARS-CoV-2 was first recognized in December of 2019 with cases of atypical 18 pneumonia in hospitalized patients in Wuhan, China. The virus is a novel beta-coronavirus, 19 related to the now eradicated, severe acute respiratory syndrome (SARS) CoV from 2003 with