Related Experiment Video
Updated: Jul 20, 2025
Microbead Implantation in the Zebrafish Embryo
Published on: July 30, 2015
ZSWIM8 destabilizes many murine microRNAs and is required for proper embryonic growth and development
Charlie Y Shi1,2,3, Lara E Elcavage1,2,3, Raghu R Chivukula4
1Howard Hughes Medical Institute, Cambridge, Massachusetts 02142, USA.
Abstract:
MicroRNAs (miRNAs) pair to sites in mRNAs to direct the degradation of these RNA transcripts. Conversely, certain RNA transcripts can direct the degradation of particular miRNAs. This target-directed miRNA degradation (TDMD) requires the ZSWIM8 E3 ubiquitin ligase. Here, we report the function of ZSWIM8 in the mouse embryo. Zswim8 -/- embryos were smaller than their littermates and died near the time of birth. This highly penetrant perinatal lethality was apparently caused by a lung sacculation defect attributed to failed maturation of alveolar epithelial cells. Some mutant individuals also had heart ventricular septal defects. These developmental abnormalities were accompanied by aberrant accumulation of more than 50 miRNAs observed across 12 tissues, which often led to enhanced repression of their mRNA targets. These ZSWIM8-sensitive miRNAs were preferentially produced from genomic miRNA clusters, and in some cases, ZSWIM8 caused a switch in the dominant strand or isoform that accumulated from a miRNA hairpin-observations suggesting that TDMD provides a mechanism to uncouple coproduced miRNAs from each other. Overall, our findings indicate that the regulatory influence of ZSWIM8, and presumably TDMD, in mammalian biology is widespread and consequential, and posit the existence of many yet-unidentified transcripts that trigger miRNA degradation.
Insights
ZSWIM8 E3 ubiquitin ligase is crucial for mammalian development, preventing microRNA (miRNA) accumulation. Loss of ZSWIM8 causes embryonic lethality due to developmental defects and aberrant miRNA levels, highlighting the importance of target-directed miRNA degradation (TDMD).
Area of Science:
- Molecular Biology
- Developmental Biology
- Genetics
Background:
- MicroRNAs (miRNAs) regulate gene expression by degrading target messenger RNAs (mRNAs).
- Target-directed miRNA degradation (TDMD) is a process where RNA transcripts degrade specific miRNAs, requiring the ZSWIM8 E3 ubiquitin ligase.
- The role of ZSWIM8 and TDMD in mammalian development is not fully understood.
Purpose of the Study:
- To investigate the function of ZSWIM8 in mouse embryonic development.
- To identify developmental abnormalities associated with ZSWIM8 deficiency.
- To explore the impact of ZSWIM8 loss on miRNA homeostasis and function.
Main Methods:
- Generation and analysis of ZSWIM8 knockout (Zswim8-/-) mouse embryos.
- Phenotypic characterization, including assessment of embryonic size, survival, and specific organ development (lungs, heart).
- High-throughput sequencing and bioinformatic analysis to profile miRNA and mRNA expression in various tissues.
Main Results:
- Zswim8-/- embryos exhibited smaller size and perinatal lethality, primarily due to lung alveolar epithelial cell maturation defects and occasional heart ventricular septal defects.
- Aberrant accumulation of over 50 miRNAs was observed across 12 tissues in mutant embryos, leading to increased repression of their mRNA targets.
- ZSWIM8-sensitive miRNAs were often derived from miRNA clusters, and ZSWIM8 activity influenced miRNA strand or isoform selection, suggesting a role in uncoupling miRNA production.
Conclusions:
- ZSWIM8 is essential for normal mammalian development, regulating miRNA levels through TDMD.
- Disruption of ZSWIM8-mediated TDMD leads to widespread miRNA dysregulation and severe developmental defects, including perinatal lethality.
- These findings underscore the significant role of ZSWIM8 and TDMD in mammalian biology and suggest the existence of numerous uncharacterized miRNA-degrading transcripts.
