Análisis in silico e interrupción del gen no codificante ter84 y estudio de ter63: efectos sobre el potencial replicativo y la longitud del telómero de Ustilago maydis

"Los RNAs largos no codificantes (lncRNAs) son una clase importante de transcritos que están implicados en una amplia variedad de funciones biológicas, los cuales son capaces de reconocer secuencias complementarias, así como de plegarse en estructuras secundarias termodinámicamente estables, que pueden servir como señales, guías, señuelos y sitios de andamiaje para proteínas involucradas en diversos procesos funcionales y regulatorios en la célula, lo que permite regular el silenciamiento transcripcional, remodelamiento de la cromatina, trafico nuclear y citoplasmático, splicing y traducción. Por otra parte, la telomerasa es un complejo enzimático ribonucleproteico que cataliza la síntesis del repetido telomérico, permitiendo mantener la integridad de los telómeros en los extremos de los cromosomas lineales de las células eucariotas, evitando que estos sean reconocidos como rupturas de doble cadena, previendo de esta forma la fusión de los extremos y eventos de degradación y recombinación, promovidos por la maquinaria de reparación del ADN celular.

Global Gene Expression of Post-Senescent Telomerase-Negative <i>ter1</i>Δ Strain of <i>Ustilago maydis</i>

We analyzed the global expression patterns of telomerase-negative mutants from haploid cells of Ustilago maydis to identify the gene network required for cell survival in the absence of telomerase. Mutations in either of the telomerase core subunits (trt1 and ter1) of the dimorphic fungus U. maydis cause deficiencies in teliospore formation. We report the global transcriptome analysis of two ter1Δ survivor strains of U. maydis, revealing the deregulation of telomerase-deleted responses (TDR) genes, such as DNA-damage response, stress response, cell cycle, subtelomeric, and proximal telomere genes. Other differentially expressed genes (DEGs) found in the ter1Δ survivor strains were related to pathogenic lifestyle factors, plant–pathogen crosstalk, iron uptake, meiosis, and melanin synthesis. The two ter1Δ survivors were phenotypically comparable, yet DEGs were identified when comparing these strains. Our findings suggest that teliospore formation in U. maydis is controlled by key pathogenic lifestyle and meiosis genes

Telomerase RNA plays a major role in the completion of the life cycle in Ustilago maydis and shares conserved domains with other Ustilaginales

The RNA subunit of telomerase is an essential component whose primary sequence and length are poorly conserved among eukaryotic organisms. The phytopathogen Ustilago maydis is a dimorphic fungus of the order Ustilaginales. We analyzed several species of Ustilaginales to computationally identify the TElomere RNA (TER) gene ter1. To confirm the identity of the TER gene, we disrupted the gene and characterized telomerase-negative mutants. Similar to catalytic TERT mutants, ter1Δ mutants exhibit phenotypes of growth delay, telomere shortening and low replicative potential. ter1-disrupted mutants were unable to infect maize seedlings in heterozygous crosses and showed defects such as cell cycle arrest and segregation failure. We concluded that ter1, which encodes the TER subunit of the telomerase of U. maydis, have similar and perhaps more extensive functions than trt1

Telomerase RNA plays a major role in the completion of the life cycle in Ustilago maydis and shares conserved domains with other Ustilaginales.

The RNA subunit of telomerase is an essential component whose primary sequence and length are poorly conserved among eukaryotic organisms. The phytopathogen Ustilago maydis is a dimorphic fungus of the order Ustilaginales. We analyzed several species of Ustilaginales to computationally identify the TElomere RNA (TER) gene ter1. To confirm the identity of the TER gene, we disrupted the gene and characterized telomerase-negative mutants. Similar to catalytic TERT mutants, ter1Δ mutants exhibit phenotypes of growth delay, telomere shortening and low replicative potential. ter1-disrupted mutants were unable to infect maize seedlings in heterozygous crosses and showed defects such as cell cycle arrest and segregation failure. We concluded that ter1, which encodes the TER subunit of the telomerase of U. maydis, have similar and perhaps more extensive functions than trt1