skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


This content will become publicly available on December 1, 2025

Title: MicroRNAs in the developmental toolbox — a comparative approach to understanding their role in regulating insect development
MicroRNAs are ubiquitous in the genomes of metazoans. Since their discovery during the late 20th century, our understanding of these small, noncoding RNAs has grown rapidly. However, there are still many unknowns about the functional significance of miRNAs — especially in non-model insects. Here I discuss the accumulating evidence that microRNAs are part of gene regulatory networks that determine not only the developmental outcome but also mediate transitions between stages and alternative developmental pathways. During the last 20 years, researchers have published a multitude of profiling studies that describe changes in miRNAs that may be important for development and catalog potential targets. Proof-of-principle studies document phenotypic changes that occur when candidate genes and/or miRNAs are inhibited or overexpressed. Studies that use both of these approaches, along with methods for confirming miRNA–mRNA interaction, demonstrate the necessary roles for miRNAs within gene networks. Together, all of these types of studies provide essential clues for understanding the function of miRNAs in the developmental toolbox.  more » « less
Award ID(s):
1755318
PAR ID:
10560599
Author(s) / Creator(s):
Publisher / Repository:
Elesevier
Date Published:
Journal Name:
Current Opinion in Insect Science
Volume:
66
Issue:
C
ISSN:
2214-5745
Page Range / eLocation ID:
101256
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Helmer-Citterich, Manuela (Ed.)
    MicroRNAs (miRNAs) play crucial roles in gene regulation. Most studies focus on mature miRNAs, which leaves many unknowns about primary miRNAs (pri-miRNAs). To fill the gap, we attempted to model the expression of pri-miRNAs in 1829 primary cell types, cell lines, and tissues in this study. We demonstrated that the expression of pri-miRNAs can be modeled well by the expression of specific sets of mRNAs, which we termed their associated mRNAs. These associated mRNAs differ from their corresponding target mRNAs and are enriched with specific functions. Most associated mRNAs of a miRNA are shared across conditions, while on average, about one-fifth of the associated mRNAs are condition-specific. Our study shed new light on understanding miRNA biogenesis and general gene transcriptional regulation. 
    more » « less
  2. MicroRNAs (miRNAs) are epigenetic markers with a key role in post-transcriptional gene regulation. Several studies have described the dysregulation of miRNAs in temperature and hypoxic stress responses of marine organisms, but their role in the response to acidification conditions has remained relatively underexplored. We investigated the differential expression of miRNAs in whole brain tissue of Arctic cod (Boregogadussaida) exposed to elevated aqueous CO2levels representative of future climate change predictions. We detected the expression of 17 miRNAs of interest that are either directly or indirectly associated with reduced auditory performance; 12 of the 17 miRNAs showed significant differential expression in high treatment vs. low (control) aqueous CO2conditions. Target gene predictions indicated that these miRNAs are likely involved with inner ear maintenance, hair cell degradation, age-related hearing loss, neural inflammation, and injury. The highest differential expression was observed in mir-135b, which is linked with increased neural inflammation and injury that may be associated with neurosensory dysfunction. Collectively, these results elucidate the contributions of miRNA mechanisms underlying CO2-induced sensory deficits in fishes facing abiotic environmental change and suggest strong potential for this approach to yield novel insights into the mechanistic effects of climate change on marine organisms. 
    more » « less
  3. Evolutionary transitions to a social lifestyle in insects are associated with lineage-specific changes in gene expression, but the key nodes that drive these regulatory changes are unknown. We examined the relationship between social organization and lineage-specific microRNAs (miRNAs). Genome scans across 12 bee species showed that miRNA copy-number is mostly conserved and not associated with sociality. However, deep sequencing of small RNAs in six bee species revealed a substantial proportion (20–35%) of detected miRNAs had lineage-specific expression in the brain, 24–72% of which did not have homologues in other species. Lineage-specific miRNAs disproportionately target lineage-specific genes, and have lower expression levels than shared miRNAs. The predicted targets of lineage-specific miRNAs are not enriched for genes with caste-biased expression or genes under positive selection in social species. Together, these results suggest that novel miRNAs may coevolve with novel genes, and thus contribute to lineage-specific patterns of evolution in bees, but do not appear to have significant influence on social evolution. Our analyses also support the hypothesis that many new miRNAs are purged by selection due to deleterious effects on mRNA targets, and suggest genome structure is not as influential in regulating bee miRNA evolution as has been shown for mammalian miRNAs. 
    more » « less
  4. High temperature impairs starch biosynthesis in developing rice grains and thereby increases chalkiness, affecting the grain quality. Genome encoded microRNAs (miRNAs) fine-tune target transcript abundances in a spatio-temporal specific manner, and this mode of gene regulation is critical for a myriad of developmental processes as well as stress responses. However, the role of miRNAs in maintaining rice grain quality/chalkiness during high daytime temperature (HDT) stress is relatively unknown. To uncover the role of miRNAs in this process, we used five contrasting rice genotypes (low chalky lines Cyp, Ben, and KB and high chalky lines LaGrue and NB) and compared the miRNA profiles in the R6 stage caryopsis samples from plants subjected to prolonged HDT (from the onset of fertilization through R6 stage of caryopsis development). Our small RNA analysis has identified approximately 744 miRNAs that can be grouped into 291 families. Of these, 186 miRNAs belonging to 103 families are differentially regulated under HDT. Only two miRNAs, Osa-miR444f and Osa-miR1866-5p, were upregulated in all genotypes, implying that the regulations greatly varied between the genotypes. Furthermore, not even a single miRNA was commonly up/down regulated specifically in the three tolerant genotypes. However, three miRNAs (Osa-miR1866-3p, Osa-miR5150-3p and canH-miR9774a,b-3p) were commonly upregulated and onemiRNA (Osa-miR393b-5p) was commonly downregulated specifically in the sensitive genotypes (LaGrue and NB). These observations suggest that few similarities exist within the low chalky or high chalky genotypes, possibly due to high genetic variation. Among the five genotypes used, Cypress and LaGrue are genetically closely related, but exhibit contrasting chalkiness under HDT, and thus, a comparison between them is most relevant. This comparison revealed a general tendency for Cypress to display miRNA regulations that could decrease chalkiness under HDT compared with LaGrue. This study suggests that miRNAs could play an important role in maintaining grain quality in HDT-stressed rice. 
    more » « less
  5. Summary MicroRNAs (miRNAs) are essential regulators of gene expression in metazoans and plants. In plants, most miRNAs are generated from primary miRNA transcripts (pri‐miRNAs), which are processed by the Dicer‐like 1 (DCL1) complex along with accessory proteins.Serrate‐Associated Protein 1 (SEAP1), a conserved splicing‐related protein, has been studied in human and yeast. However, the functions of SEAP1 in plants remain elusive.Lack ofSEAP1results in embryo lethality and knockdown ofSEAP1by an artificial miRNA (amiRSEAP1) causes pleiotropic developmental defects and reduction in miRNA accumulation. SEAP1 associates with the DCL1 complex, and may promote the interaction of the DCL1 complexes with pri‐miRNAs. SEAP1 also enhances pri‐miRNA accumulation, but does not affect pri‐miRNA transcription, suggesting it may indirectly or directly stabilize pri‐miRNAs. In addition, SEAP1 affects the splicing of some pri‐miRNAs and intron retention of messenger RNAs at global levels.Our findings uncover both conserved and novel functions of SEAP1 in plants. Besides the role as a splicing factor, SEPA1 may promote miRNA biogenesis by positively modulating pri‐miRNA splicing, processing and/or stability. 
    more » « less