Identification And Functional Analysis Of CircRNAs In Spores And Hyphae Of Trichophyton Rubrum

CircRNA is a non-coding RNA.CircRNA has high abundance and is not easily degraded by a series of enzymes.Some circRNAs only functions in specific cells,and circRNAs have a very important relationship with clinical diseases,so circRNA can become a medical diagnosis and treatment of various diseases in the future.The function and regulation of circRNA have been extensively studied in animals and plants,but the research in fungi needs to be followed up.Trichophyton rubrum is an important model organism,used to explore the mechanism of pathogenic bacteria and superficial pathogenic fungi.This article focuses on identifying the circRNA of T.rubrum at the spore and hyphae stage,and analyzes the biological pathways of circRNA regulating gene expression in the above two important growth stages,and its influence on the growth and development of T.rubrum.High-throughput sequencing of the transcriptome of the two important growth stages of T.rubrum revealed 4254 circRNAs,3980 circRNAs and 778 circRNAs were found from spores and hyphae respectively.Using the circ-AS tool to study the mechanism of circRNA production,it was found that there are 4 variable splicing modes in T.rubrum:exon skipping(ES),intron retention(IR),and 5'Splice site(A5SS)and 3'splice site(A3SS).The same host gene generates various circRNAs through the circ-AS pattern,including 94 and 10 circ-AS patterns for spores and hyphae respectively.In both spores and hyphae,circRNA showed specific expression.The number specifically produced only in spores was 3476,and 274 in hyphae.Among differentially expressed 940 circRNAs,930 circRNAs were up-regulated in spores,and 10 circRNAs were down-regulated.Seven randomly selected significantly differentially expressed circRANs used convergent primers and divergent primers for PCR,which confirmed the circular structure of circRAN and confirmed the high accuracy of the sequencing results.The prediction is based on competitive endogenous RNA(ceRNA)(circRNA-miRNA-mRNA).Among them,661 DE-circRNAs can adsorb 140 miRNAs and regulate 2753 target genes.In the circRNA-miRNA-mRNA regulatory network,the expression regulation direction of circRNA and mRNA is the same,and the direction of expression regulation is opposite to that of miRNA.This result suggests that circRNA and miRNA may participate in gene expression regulation through ceRNA mechanism in T.rubrum.The functional analysis of the 2753 target genes GO and KEGG found that these target genes are mainly involved in the processes related to the synthesis,processing and metabolism of RNA and ribosomes,as well as some small molecule metabolism,such as the biogenesis of ribonucleoprotein complexes,rRN A metabolic processes and RNA metabolism process,RNA degradation,ribosome synthesis,small molecule catabolism process and carboxylic acid metabolism process.Through the analysis of the conservation of circRNA,it was found that the circRNA of T.rubrum was highly conserved in 11 closely related superficial infection fungi,but was less conserved in 6 distant plant,animal and nematode model organisms.However,there is a special circRNA(Tru_circ07138₀01),which is conserved among 11 superficially infected fungi,and the sequence homology among the distant species chicken,nematode and cotton is as high as 81.08%,94.30%and 81.82,respectively.Among them,the corresponding protein sequences in T.rubrum,chickens and nematodes share more than 90%homology.They all belong to the polyubiquitin-related gene family and participate in the proteolysis of damaged proteins.The circRNA of T.rubrum was identified for the first time at the whole genome level,and the characteristics,functions,production and regulation mechanisms of the identified circRNA were studied.At the same time,the conservation of circRNA in near and distant organisms was studied.In addition,the relationship between the changes in circRNA levels in spores and hyphae and the changes in mRNA expression levels of the genes was analyzed.The results of this article lay the foundation for the in-depth study of the regulation mechanism of circRNA in T.rubrum and the role of circRNA in the growth and development of T.rubrum,and also for further research on the biology of T.rubrum and other homologous fungi Features provide beneficial clues.