Neurospora crassa transcriptomics reveals oxidative stress and plasma membrane homeostasis biology genes as key targets in response to chitosan

Chitosan is a natural polymer with antimicrobial activity. Chitosan causes plasma membrane permeabilization and induction of intracellular reactive oxygen species (ROS) in Neurospora crassa. We have determined the transcriptional profile of N. crassa to chitosan and identified the main gene targets involved in the cellular response to this compound. Global network analyses showed membrane, transport and oxidoreductase activity as key nodes affected by chitosan. Activation of oxidative metabolism indicates the importance of ROS and cell energy together with plasma membrane homeostasis in N. crassa response to chitosan. Deletion strain analysis of chitosan susceptibility pointed NCU03639 encoding a class 3 lipase, involved in plasma membrane repair by lipid replacement, and NCU04537 a MFS monosaccharide transporter related to assimilation of simple sugars, as main gene targets of chitosan. NCU10521, a glutathione S-transferase-4 involved in the generation of reducing power for scavenging intracellular ROS is also a determinant chitosan gene target. Ca2+ increased tolerance to chitosan in N. crassa. Growth of NCU10610 (fig 1 domain) and SYT1 (a synaptotagmin) deletion strains was significantly increased by Ca2+ in the presence of chitosan. Both genes play a determinant role in N. crassa membrane homeostasis. Our results are of paramount importance for developing chitosan as an antifungal.

Anglicisms and calques in upper social class in pre-revolutionary Cuba (1930–1959): A sociolinguistic analysis

The geographical proximity and socioeconomic dependence on the United States brought about a deep rooted anglicization of the Cuban Spanish lexis and social strata, especially throughout the Neocolonial period (1902–1959). This study is based on the revision of a renowned newspaper of that time, Diario de la Marina, and the corresponding elaboration of a corpus of English-induced loanwords. Diario de la Marina particularly targeted upper social class, and only crónicas sociales (society pages’ columns) and print advertising were revised because of their fully descriptive texts, which encoded the ruling class ideology and consumerism. The findings show that there existed a high number of lexical and cultural anglicisms in the sociolect in question, and that the sociolinguistic anglicization was openly embraced by the upper socioeconomic stratum, entailing a differentiating sign of sophistication and social stratification. Likewise, a number of the anglicisms collected, particularly those related with social events, are unused in contemporary Cuban Spanish, which suggests a major semantic shifting in this sociolect after 1959.