MiR-92 Family Members Form a Cluster Required for Notochord Tubulogenesis in Urochordate Ciona savignyi | JoVE Visualize

MiR-92 Family Members Form a Cluster Required for Notochord Tubulogenesis in Urochordate Ciona savignyi

Libo Yang¹, Xiaoming Zhang^1,2, Chengzhang Liu³

¹Sars-Fang Centre, MoE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.

Genes|April 3, 2021

View abstract on PubMed

Summary

We identified a miR-92 cluster in the urochordate Ciona savignyi, revealing conserved sequences and crucial roles in notochord development. This study enhances understanding of miRNA cluster evolution and function.

Area of Science:

Developmental Biology
Genomics
Molecular Biology

Background:

MicroRNAs (miRNAs) are key regulators of gene expression, often organized in genomic clusters and transcribed polycistronically.
The miR-17-92 cluster is well-characterized in vertebrates for its roles in organogenesis and homeostasis.
Urochordates, like the marine ascidian Ciona savignyi, offer insights into the evolution of developmental pathways.

Purpose of the Study:

To identify and characterize miRNA clusters in the urochordate Ciona savignyi.
To investigate the expression patterns and functional roles of miR-92 family members in Ciona.
To explore the evolutionary conservation and regulatory functions of miRNA clusters.

Main Methods:

Bioinformatic analysis to identify miRNA clusters in the Ciona genome.
Sequence conservation analysis comparing Ciona miRNAs with vertebrate homologs.
In situ hybridization to determine spatiotemporal expression patterns during embryonic development.
Gene knockout experiments to assess functional roles in notochord development.
Prediction of target genes within key signaling pathways (FGF, MAPK, Wnt/PCP).

Main Results:

Three miR-92 family members (csa-miR-92a, csa-miR-92b, csa-miR-92c) forming a miRNA cluster were identified in Ciona savignyi.
Mature sequences of Ciona miR-92 family members showed high conservation with vertebrate counterparts.
Knockout of csa-miR-92c disrupted notochord cell organization and lumen coalescence, suggesting a critical role in organogenesis.
Predicted targets included core genes of FGF, MAPK, and Wnt/PCP signaling pathways.

Conclusions:

A functional miR-92 cluster exists in urochordates, highlighting conserved roles in vertebrate and invertebrate development.
csa-miR-92c plays a vital role in Ciona notochord development, likely through regulation of conserved signaling pathways.
This study provides valuable expression and phylogenetic data for understanding the evolution of the miR-92 miRNA cluster.