The newly identified SARS CoV2 has become a global pandemic since December 2019. Various researchers are trying to design a vaccine candidate against the virus. On the other hand, another group is focussing on repurposing approved or clinically tested drugs for treatment. However, there is always a search for alternative therapies. Thus, we propose an alternative approach apart from chemotherapy that is the usage of miRNA as novel antisense therapy to cure SARS CoV2 infected patients. To address the objective, miRNAs have been designed by targeting the genome of SARS CoV2 (Indian isolate). First, the open reading frames in the viral genome have been identified, and the proteins encoded by those open reading frames have been predicted. Using computational biology, several miRNAs have been designed and their probability to bind to a viral gene has been predicted. In addition, miRNA target mining in the host cell has been done to rule out the possibility of non-specific binding of the miRNAs. The miRNAs having the highest chances to bind to the viral genome have been converted into pre-miRNAs, and their interaction with dicer endoribonuclease has been studied by molecular docking. Results revealed that the pre-miRNAs interact with the RNAse III 2 domain of dicer. Thus, it is predicted that the pre-miRNAs after delivery to the infected host cell will be processed by dicer to generate mature miRNAs that will target the SARS CoV2 viral genome. Therefore, miRNA therapy can be an alternative approach for the treatment of SARS CoV2 infection.

Since 2007, the annual green tide disaster in the Yellow Sea has brought serious economic losses to China. There is no research on the genetic similarities of four constituent species of green tide algae at the genomic level. We previously determined the mitochondrial genomes of Ulva prolifera, Ulva linza and Ulva flexuosa. In the present work, the mitochondrial genome of another green tide (Ulva compressa) was sequenced and analyzed. With the length of 62,311 bp, it contained 29 encoding genes, 26 tRNAs and 10 open reading frames. By comparing these four mitochondrial genomes, we found that U. compressa was quite different from the other three types of Ulva species. However, there were similarities between U. prolifera and U. linza in the number, distribution and homology of open reading frames, evolutionary and codon variation of tRNA, evolutionary relationship and selection pressure of coding genes. Repetitive sequence analysis of simple sequence repeats, tandem repeat and forward repeats further supposed that they have evolved from the same origin. In addition, we directly analyzed gene homologies and translocation of four green tide algae by Mauve alignment. There were gene order rearrangements among them. With fast-evolving genomes, these four green algal mitochondria have both conservatism and variation, thus opening another window for the understanding of origin and evolution of Ulva.