# Protocol to investigate the effects of localized gene expression disruption on mouse limb development via direct siRNA injection and explant culture

**Authors:** Ji-Hye Yea, Sharon E.S. Onggo, Suhani Dewagan, Kaiwen Chen, Kaily K. Young, Patrick Cahan

PMC · DOI: 10.1016/j.xpro.2026.104402 · STAR Protocols · 2026-02-28

## TL;DR

This paper provides a detailed protocol for using siRNA injections to study gene effects on mouse limb development.

## Contribution

A novel protocol for localized gene knockdown in mouse limb explants using siRNA injection and morphology scoring.

## Key findings

- A protocol for localized gene knockdown in embryonic mouse hindlimb explants is described.
- The method includes siRNA injection and a semi-quantitative scoring system for developmental outcomes.
- The approach allows spatially precise modulation of gene expression during limb development.

## Abstract

Here, we present a protocol for localized gene knockdown in embryonic mouse hindlimb explants using direct small interfering RNA (siRNA) injection, combined with a semi-quantitative morphology scoring system to assess developmental outcomes. We describe steps for mating of samples, preparing hindlimb explants for culture and siRNA-Lipofectamine complex, and direct injection of the siRNA-Lipofectamine complex. We then detail procedures for explant culture and maintenance, data analysis, tissue fixation, and cryoprotection. This protocol approach enables spatially precise modulation of gene expression during limb and joint development.

•Steps for direct injection of gene expression modulators into embryonic limb explants•Guidance on explant culture and localized gene modulation•Instruction for semi-quantitative scoring of limb and joint morphology

Steps for direct injection of gene expression modulators into embryonic limb explants

Guidance on explant culture and localized gene modulation

Instruction for semi-quantitative scoring of limb and joint morphology

Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Here, we present a protocol for localized gene knockdown in embryonic mouse hindlimb explants using direct small interfering RNA (siRNA) injection, combined with a semi-quantitative morphology scoring system to assess developmental outcomes. We describe steps for mating of samples, preparing hindlimb explants for culture and siRNA-Lipofectamine complex, and direct injection of the siRNA-Lipofectamine complex. We then detail procedures for explant culture and maintenance, data analysis, tissue fixation, and cryoprotection. This protocol approach enables spatially precise modulation of gene expression during limb and joint development.

## Linked entities

- **Chemicals:** Lipofectamine (PubChem CID 100984821)
- **Species:** Mus musculus (taxon 10090)

## Full-text entities

- **Genes:** Sox9 (SRY (sex determining region Y)-box 9) [NCBI Gene 20682] {aka 2010306G03Rik, mKIAA4243, mSox9}, Gdf5 (growth differentiation factor 5) [NCBI Gene 14563] {aka BMP-14, Cdmp-1, bp, brp}
- **Chemicals:** trypan blue (MESH:D014343), saline (MESH:D012965), ethanol (MESH:D000431), Lipofectamine (MESH:C086724), Alexa Fluor Red (-), Fluo (MESH:C097499), PBS (MESH:D007854), CD (MESH:D002104), sucrose (MESH:D013395), paraformaldehyde (MESH:C003043), CM (MESH:D003476), CO2 (MESH:D002245)
- **Species:** Mus musculus (house mouse, species) [taxon 10090]

## Full text

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## Figures

9 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12964285/full.md

## References

14 references — full list in the complete paper: https://tomesphere.com/paper/PMC12964285/full.md

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Source: https://tomesphere.com/paper/PMC12964285