Loss of heterozygosity by mitotic recombination in diploid strain of Aspergillus nidulans in response to castor oil plant detergent

Abstract

Somatic recombination in heterozygous diploid cells may be a promotional agent of neoplasms by inducing homozygosity of defective genes. Tumor suppressor genes may in this way be completely suppressed in recombinant cells. In this work, the genotoxic effects of detergent derived from the castor oil plant (Ricinus communis) in heterozygous diploid cells of Aspergillus nidulans are evaluated. Previous studies have evaluated the application of this substance in endodontic treatments as an irrigating solution. The recombinogenic potential of the compound has been studied through the production of homozygous cells for nutritional markers riboA1, pabaA124, biA1, methA17, and pyroA4. Detergent was diluted to 1:10, 1:20, and 1:40, and morphologic alterations, delay in conidiophore development, and mitotic recombination occurrence were reported for the three dilutions. Although past studies have demonstrated the antimicrobial action of the detergent under analysis, our results revealed its cytotoxic effects and recombinogenic potential.

Chlorhexidine digluconate induces mitotic recombination in diploid cells of Aspergillus nidulans

“…Mitotic recombination leads the expression of recessive genes in heterozygous cells. Since tumor suppressor genes may be completely suppressed in recombinant cells, studies have been performed to identify the recombinogenic potential of several chemical agents (Chiuchetta and Castro‐Prado, 2002b; Souza‐Júnior et al , 2004). Thus, the determination of mitotic crossing‐over frequency induced by chemical substances constitutes a very important method for studying carcinogenic agents (Wang et al , 1988).…”

Review of current and “omics” methods for assessing the toxicity (genotoxicity, teratogenicity and nephrotoxicity) of herbal medicines and mushrooms

“…Eukaryotic organisms: Aspergillus nidulans. Because of its parasexual cycle, the filamentous fungus Aspergillus nidulans constitutes an excellent system for studying mitotic crossingover, since its cells spend a substantial part of their cell cycle in the G2 phase during the germination period; two copies of each chromosome during that period of the cell cycle significantly favors a mitotic recombination event, visually detected by simple plating tests (Osman et al, 1993;Souza-Júnior et al, 2004).…”

Inibição do desenvolvimento de fungos fitopatogênicos por detergente derivado de óleo da mamona (Ricinus communis)

“…No fungo filamentoso Aspergillus nidulans, o detergente derivado do óleo da mamona induziu alterações morfológicas nas colônias e nos conidióforos, atraso na produção de conídios e aumento nas freqüências de recombinação mitótica na linhagem diplóide UT448//UT196 (SOUZA-JÚNIOR et al, 2004).…”

“…As concentrações de DOM que induziram más-formações nos conidióforos e atraso na conidiogênese em A. nidulans (SOUZA-JÚNIOR et al, 2004) foram tomadas como referência no presente trabalho.…”