About BonnMu

What is BonnMu?

The BonnMu resource is a public transposon-tagged population designed for reverse and forward genetics studies in maize (Zea mays L.). The resource was created by crossing an active Mutator (Mu) transposon stock into different inbred lines (i.e., B73, Co125, DK105, EP1, F7) to induce insertional mutations. The resulting F1 generation was self-pollinated to generate segregating BonnMu F2 stocks. The Mu-tagged BonnMu F2 stocks have insertions in 84% of all annotated maize gene models, and Mu insertion positions and photos of the seedling phenotypes of the segregating BonnMu F2 stocks are deposited in the Maize Genetics and Genomics Database (MaizeGDB), with seeds available to the community.

How many Mu-tagged genes were identified so far?

Sequencing of segregating F2 stocks is still ongoing. Currently, 9216 segregating F2 stocks in different inbred background are analyzed.

Aligning Mu insertions to B73 Ref-NAM-5.0 identified more than 426,000 unique germinal Mu insertions covering 37,269 of all maize genes. Find the updated list of all Mu insertion sites here: BonnMu_6th Release_10-28-20241.

How to look for a Mu insertion in your gene of interest?

To access and visualize B73 insertions in jbrowse.maizegdb.org, select your gene model of interest and activate the BonnMu insertion view by scrolling down the available tracks. Clicking on the insertion site links to the Mu insertion identifiers and the respective F2 stock, i.e., a photo of the segregating BonnMu F2 stock, 10 days after germination.

Table 1
© Caroline Marcon

A subset of Mu insertion sites is illustrated. One row and one column (col) pool (Sample-Pool) represent one germinal insertion, supported by at least 2 raw reads on either side of the insertion, which is represented by the 9 bp target site duplication (TSD).

How to order Mu-induced stocks for your research?

Seeds can be requested by E-Mail to: BonnMu@uni-bonn.de.
We ship ten seeds per F2 or F3 stock which means you have to propagate them before using them. There is no fee for the seeds. We share the seeds on a collaborative basis. We will send you an MTA (material transfer agreement) according to our University‘s policy. Shipping to the US requires an import permit to be applied by the USDA. The import permit comes along with green/yellow labels that certify the small lots of seeds as quarantine material. We are not shipping via phytosanitary certificate! And we are only shipping via FedEx international transport. Detailed information for US requesters can be downloaded here: BonnMu_Infos for requesters_April 20222

How to validate Mu insertions in the stocks?

We recommend PCR confirmation of Mu insertions by using gene-specific primers (at least one upstream and one downstream of the insertion site) in combination with a MuTIR primer (Figure 1).

More details on the PCR-based confimation of Mu insertions are described by the UniformMu group: https://www.maizegdb.org/uniformmu3.

Figure 1
© Caroline Marcon

Figure 1: A) One BonnMu stock carries a Mu insertion in the roothair defective 3 (rth3) gene (Hochholdinger et al., 2008). The rth3 mutants lack roothairs. B) Cartoon of the rth3 gene, disrupted by a Mu insertion in the single exon. The internal Mu-sequence is shown in yellow, the terminal inverted repeat (TIR) at either end of the transposon is shown in red. Positions of a rth3-specific forward (For) and reverse primer (Rev) are illustrated as green and purple arrows. These primers flank the insertion site. The red arrows display the outward reading TIR-specific primer of the Mu transposon. C) PCR analysis using WT DNA and rth3 mutant DNA as template. Gene-specific For and Rev primers amplified a specific PCR-product of expected size from WT DNA, wheras no PCR product was amplified with rth3 DNA samples as template. In contrast, only dominant products of expected size were amplified from the mutant DNA, when gene-specific primers were combined with the MuTIR primer.

References:

  •  Win YN, Stöcker T, Du X, Brox A, Pitz M, Klaus A, Schoof H, Hochholdinger F, Marcon C (2024) Expanding the BonnMu sequence-indexed repository of transposon induced maize (Zea mays L.) mutations in dent and flint germplasm. Plant J. https://doi.org/10.1101/tpj.170884
  • Marcon C, Altrogge L, Win Y, Stöcker T, Gardiner JM, Portwood JL, Opitz N, Kortz A, Baldauf J, Hunter CT, McCarty DR, Koch KE, Schoof H, Hochholdinger F (2020) BonnMu: a sequence-indexed resource of transposon induced maize mutations for functional genomics studies. Plant Physiol. https://doi.org/10.1104/pp.20.004785
  • Hochholdinger F, Wen T-J, Zimmermann R, Chimont-Marolle P, da Costa e Silva O, Bruce W, Lamkey KR, Wienand U, Schnable PS (2008) The maize (Zea mays L.) roothairless3 gene encodes a putative GPI-anchored, monocot-specific, COBRA-like protein that significantly affects grain yield. Plant J. https://doi.org/10.1111/j.1365-313X.2008.03459.x6

Links

  1. https://www.inres.uni-bonn.de/cfg/en/medien/research/bonnmu/bonnmu_6th-release_10-28-24.xlsx
  2. https://www.inres.uni-bonn.de/cfg/en/pdf/bonnmu_infos-for-requesters_april-2022.pdf
  3. https://www.maizegdb.org/uniformmu
  4. https://doi.org/10.1101/tpj.17088
  5. https://doi.org/10.1104/pp.20.00478
  6. https://doi.org/10.1111/j.1365-313X.2008.03459.x