Small regulatory noncoding RNAs in Drosophila melanogaster: biogenesis and biological functions

Abstract

RNA interference (RNAi) is an important phenomenon that has diverse genetic regulatory functions at the pre- and posttranscriptional levels. The major trigger for the RNAi pathway is double-stranded RNA (dsRNA). dsRNA is processed to generate various types of major small noncoding RNAs (ncRNAs) that include microRNAs (miRNAs), small interfering RNAs (siRNAs) and PIWI-interacting RNAs (piRNAs) in Drosophila melanogaster (D. melanogaster). Functionally, these small ncRNAs play critical roles in virtually all biological systems and developmental pathways. Identification and processing of dsRNAs and activation of RNAi machinery are the three major academic interests that surround RNAi research. Mechanistically, some of the important biological functions of RNAi are achieved through: (i) supporting genomic stability via degradation of foreign viral genomes; (ii) suppressing the movement of transposable elements and, most importantly, (iii) post-transcriptional regulation of gene expression by miRNAs that contribute to regulation of epigenetic modifications such as heterochromatin formation and genome imprinting. Here, we review various routes of small ncRNA biogenesis, as well as different RNAi-mediated pathways in D. melanogaster with a particular focus on signaling pathways. In addition, a critical discussion of the most relevant and latest findings that concern the significant contribution of small ncRNAs to the regulation of D. melanogaster physiology and pathophysiology is presented.

Functional role of piRNAs in animal models and its prospects in aquaculture

“…Later, the primary piRNA binds to the transposable element mRNA sequences and causes post-transcriptional silencing of transposons. Some of the trigger sequences binding to the precursor piRNA are NXF1 and NXT1 (Soleimani et al 2020), which help to transport the piRNA precursor to the cytoplasm. Co-chaperone Hsp70-Hsp90 is another essential protein studied to be involved in the primary biogenesis process and help maintain the genomic integrity by silencing transposons.…”

Non-coding RNAs in Regulating Tumor Angiogenesis

“…This amplification cycle continues with the continuous expression of Aub and AGO3, thereby causing a large amount of piRNA in the cell to be amplified. This phenomenon is called the “Ping-Pong” cycle ( Soleimani et al, 2020 ). PiRNA mainly binds with PIWI or AGO3 protein, a member of the PIWI subfamily, to maintain genome stability by silencing transposable elements and regulating coding mRNA ( Ng et al, 2016 ).…”

Diverse Defenses: A Perspective Comparing Dipteran Piwi-piRNA Pathways

“…Several other reviews have comprehensively covered the complex biogenesis mechanism of piRNAs that are clearly distinct from miRNA and siRNA biogenesis [ 34 , 43 , 118 , 160 , 161 , 162 ]. We summarize here the two key facets of piRNA biogenesis mechanisms that were first determined with Drosophila mutants and deep sequencing small RNA profiling [ 29 , 35 , 163 ] in order to then highlight one extraordinary aspect of mosquito piRNA biogenesis [ 46 ].…”