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Non-coding RNA fragments (ncRFs) are small RNA fragments processed from non-coding RNAs (ncRNAs). ncRFs have various functions and are commonly tissue-specific, and their processing is altered by exposure to stress. Information about ncRFs in the brain is scarce. Recently, we reported the brain region-specific and sex-specific expression of ncRNAs and their processing into ncRFs. Here, we analyzed the expression of ncRFs in the frontal cortex (FC), hippocampus (HIP), and cerebellum (CER) of male and female rats exposed to scatter radiation. We found multiple brain region- and sex-specific changes in response to scatter radiation. Specifically, we observed decreased miRNA expression and the increased expression of ra-ncRNA reads in HIP and CER, as well as an increased number of mtR-NA-associated reads in HIP. We also observed the appearance of sense-intronic ncRNAs—in females, in HIP and FC, and in males, in CER. In this work, we also show that tRNA-GlyGCC and tRNA-GlyCCC are most frequently processed to tRFs, in CER in females, as compared to males. An analysis of the targeted pathways revealed that tRFs and snoRFs in scatter radiation samples mapped to genes in several pathways associated with various neuronal functions. While in HIP and CER these pathways were underrepresented, in FC, they were overrepresented. Such changes may play an important role in pathologies that develop in response to scatter radiation, the effect known as "radio-brain", and may in part explain the sex-specific differences observed in animals and humans exposed to radiation and scatter radiation. [ABSTRACT FROM AUTHOR]

Non-coding RNA fragments (ncRFs) are processed from various non-coding RNAs (ncRNAs), with the most abundant being those produced from tRNAs. ncRFs were reported in many animal and plant species. Many ncRFs exhibit tissue specificity or/and are affected by stress. There is, however, only a handful of reports that describe differential expression of ncRFs in the brain regions. In this work, we analyzed the abundance of ncRFs processed from four major ncRNAs, including tRNA (tRFs), snoRNA (snoRFs), snRNA (snRFs), and rRNA (rRFs) in the frontal cortex (FC), hippocampus (HIP), and cerebellum (CER) of male and female rats. We found brain-specific and sex-specific differences. Reads mapping to lincRNAs were significantly larger in CER as compared to HIP and CER, while those mapping to snRNAs and tRNA were smaller in HIP than in FC and CER. tRF reads were the most abundant among all ncRF reads, and FC had more reads than HIP and CER. Reads mapping to antisense ncRNAs were significantly larger in females than in males in FC. Additionally, males consistently had more tRF, snRF, and snoRF reads in all brain regions. rRFs were more abundant in males in FC and females in HIP. Several tRFs were significantly underrepresented, including tRF-ValCAC, tRF-ValACC, and tRF-LysCTT in all brain regions. We also found brain- and sex-specific differences in the number of brain function-related mRNA targets. To summarize, we found sex-specific differences in the expression of several ncRNA fragments in various brain regions of healthy rats. [ABSTRACT FROM AUTHOR]

Non-coding RNA fragments (ncRFs) are processed from various non-coding RNAs (ncRNAs), with the most abundant being those produced from tRNAs. ncRFs were reported in many animal and plant species. Many ncRFs exhibit tissue specificity or/and are affected by stress. There is, however, only a handful of reports that describe differential expression of ncRFs in the brain regions. In this work, we analyzed the abundance of ncRFs processed from four major ncRNAs, including tRNA (tRFs), snoRNA (snoRFs), snRNA (snRFs), and rRNA (rRFs) in the frontal cortex (FC), hippocampus (HIP), and cerebellum (CER) of male and female rats. We found brain-specific and sex-specific differences. Reads mapping to lincRNAs were significantly larger in CER as compared to HIP and CER, while those mapping to snRNAs and tRNA were smaller in HIP than in FC and CER. tRF reads were the most abundant among all ncRF reads, and FC had more reads than HIP and CER. Reads mapping to antisense ncRNAs were significantly larger in females than in males in FC. Additionally, males consistently had more tRF, snRF, and snoRF reads in all brain regions. rRFs were more abundant in males in FC and females in HIP. Several tRFs were significantly underrepresented, including tRF-ValCAC, tRF-ValACC, and tRF-LysCTT in all brain regions. We also found brain- and sex-specific differences in the number of brain function-related mRNA targets. To summarize, we found sex-specific differences in the expression of several ncRNA fragments in various brain regions of healthy rats.

Non-coding RNA fragments (ncRFs) represent a large spectrum of short ncRNAs processed from precursor ncRNAs such as tRNA, rRNA, snoRNA and several others. Several recent papers suggest that ncRFs are processed in a specific manner in different tissues or in response to stress. Here, we analyzed alterations in the expression of ncRFs in different Brassica rapa tissues in response to heat stress. Specifically, we analyzed the abundance of tRNA fragments (tRFs), rRNA fragments (rRFs), snoRNA fragments (snoRFs) and snRNA fragments (snRFs). The most significant changes in response to heat stress were observed in tRNA Glu and tRNA Asp . Whereas the number of reads mapping to the former one dropped drastically in all tissues but the apical meristem and pollen, the number of reads mapping to the latter significantly increased. Analysis of tRFs showed that three isoacceptors, tRF5′ Asp(GUC) , tRF Gly(UCC) and tRF Pseudo(UCC) were severely underrepresented in heat-stressed tissues. Heat also induced changes in the processing of ncRFs from precursor molecules; a bias towards the processing of ncRFs from the 3′ end was even more prominent after the heat stress application. The analysis of predicted targets of ncRFs revealed an enrichment in several groups of genes involved in the response to various stresses. To conclude, our work showed that heat stress results in tissue-specific changes in the expression of ncRFs in Brassica rapa and suggested a tissue-specific regulation of various mRNAs and pathways in response to heat. [ABSTRACT FROM AUTHOR]

Recently, a novel type of non-coding RNA (ncRNA), known as ncRNA fragments or ncRFs, has been characterised in various organisms, including plants. The biogenesis mechanism, function and abundance of ncRFs stemming from various ncRNAs are poorly understood, especially in plants. In this work, we have computationally analysed the composition of ncRNAs and the fragments that derive from them in various tissues of Brassica rapa plants, including leaves, meristem tissue, pollen, unfertilized and fertilized ova, embryo and endosperm. Detailed analysis of transfer RNA (tRNA) fragments (tRFs), ribosomal RNA (rRNA) fragments (rRFs), small nucleolar RNA (snoRNA) fragments (snoRFs) and small nuclear RNA (snRNA) fragments (snRFs) showed a predominance of tRFs, with the 26 nucleotides (nt) fraction being the largest. Mapping ncRF reads to full-length mature ncRNAs showed a strong bias for one or both termini. tRFs mapped predominantly to the 5' end, whereas snRFs mapped to the 3' end, suggesting that there may be specific biogenesis and retention mechanisms. In the case of tRFs, specific isoacceptors were enriched, including tRNA Gly(UCC) and tRF Asp(GUC) . The analysis showed that the processing of 26-nt tRF5' occurred by cleavage at the last unpaired nucleotide of the loop between the D arm and the anticodon arm. Further support for the functionality of ncRFs comes from the analysis of binding between ncRFs and their potential targets. A higher average percentage of binding at the first half of fragments was observed, with the highest percentage being at 2-6 nt. To summarise, our analysis showed that ncRFs in B. rapa are abundantly produced in a tissue-specific manner, with bias toward a terminus, the bias toward the size of generated fragments and the bias toward the targeting of specific biological processes.