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Related Experiment Video

Updated: Jan 29, 2026

Examination of Thymic Positive and Negative Selection by Flow Cytometry

Examination of Thymic Positive and Negative Selection by Flow Cytometry

Published on: October 8, 2012

PIG-mediated cassava transformation using positive and negative selection.

P Zhang¹, J Puonti-Kaerlas¹

¹Institute for Plant Sciences, ETH-Zentrum / LFW E 17, CH-8092 Zürich, Switzerland e-mail: johanna.puonti-kaerlas@ipw.biol.ethz.ch Fax: +41-1-6321044, , , , , , CH.

Plant Cell Reports

|February 14, 2019

Summary

This summary is machine-generated.

This study developed new, non-antibiotic selection systems for creating transgenic cassava (Manihot esculenta Crantz) plants. Positive selection using mannose proved effective for regenerating genetically modified cassava.

Keywords:

Abbreviations2,4-D 2,4-Dichlorophenoxyacetic acid BA 6-Benzylaminopurine Biolistics CBM Basic medium CEM Elongation medium CIM Embryo induction medium CMM Maturation medium COM Organogenesis medium CTM Transformation medium FEC Friable embryogenic callus GD Gresshoff and Doy medium IBA Indole-3-butyric acid Key words Cassava (Manihot esculenta Crantz)MSM Solid mannose selection medium MSN FEC Formation and embryo conversion medium NAAα-Naphthalene acetic acid Negative selection Positive selection SCV Settled cell volume SH Schenk and Hildebrandt medium SHM Liquid mannose selection medium Transformation

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Area of Science:

Plant Biotechnology
Molecular Biology
Agricultural Science

Background:

Developing efficient selection systems is crucial for producing transgenic crops like cassava.
Traditional antibiotic-based selection methods can have limitations.

Purpose of the Study:

To assess the efficiency of positive selection using mannose and negative selection using hygromycin for transgenic cassava regeneration.
To optimize selection protocols for producing transgenic cassava plants.

Main Methods:

Somatic cotyledon and embryogenic suspension explants were used for particle inflow gun bombardment.
Positive selection with mannose and negative selection with hygromycin were evaluated.
PCR, RT-PCR, Southern, and northern analyses confirmed stable transformation and transgene expression.

Main Results:

Transgenic cassava plants were successfully obtained using both mannose-based positive selection and hygromycin-based negative selection (in embryogenic suspensions).
A novel rooting test on mannose-supplemented medium enhanced the positive selection system's efficacy.
Stable transformation and transgene expression were rigorously verified.

Conclusions:

Non-antibiotic positive selection using mannose is a viable method for producing transgenic cassava.
Optimized selection strategies contribute to more efficient genetic engineering of cassava.