Frank Hochholdinger

Nice coverage of one of our recent papers by a media outlet. Not so happy with the AI generated maize root system they used to illustrate their article. 😬

Korrekt müsste es heissen: „Silphie ist eine ökol. vorteilhafte Alternative zur Maissorte PM Paolo“. Ob das generell auf Mais zutrifft, lässt sich aus dieser Studie mit nur einer Maissorte nicht sagen.

Finally, we identified a gene that regulates lateral root density in hybrids depending on the genetic constitution of its regulatory eQTL. 7/7

Importantly, SPE genes were mainly regulated by heterozygous eQTL, underscoring the importance of heterozygosity for the regulation of dominant loci, thus reconciling the competing genetic hypotheses of overdominance (heterozygote advantage) and dominance (complementation) to explain heterosis. 6/7

Single parent expression (SPE) complementation, an expression pattern in which genes are expressed in only one parent and in the hybrid, consistent with dominance, explained up to 29% of heterotic variance for root traits. 5/7

In general, these partial hybrids expressed more genes than their parental lines (IBM-RIL and B73 or Mo17). 4/7

Replicated RNA-seq of 852 samples led to clearly separated genotypic clusters in an MDS plot. 3/7

We generated backcrosses of 112 intermated B73xM17 recombinant inbred lines to their parents B73 and Mo17, thus generating a set of partial hybrids with an average heterozygosity of 50%. 2/7

Regulation of heterosis-associated gene expression complementation in maize hybrids - Genome Biology Background Classical genetic concepts to explain heterosis attribute the superiority of F1-hybrids over their homozygous parents to the complementation of unfavorable by beneficial alleles (dominance) or to heterozygote advantage (overdominance). Here we analyze 112 intermated B73xMo17 recombinant inbred lines of maize and their backcrosses to their original parents B73 and Mo17 to obtain hybrids with an average heterozygosity of ~ 50%. This genetic architecture allows studying the influence of homozygous and heterozygous genomic regions on gene expression in hybrids. Results We demonstrate that single parent expression (SPE) complementation explains between − 8% and 29% of the mid-parent heterotic variance in these hybrids. In this expression pattern, consistent with dominance, genes are active in only one parent and in the hybrid, thus increasing the number of expressed genes in hybrids. Furthermore, we establish that eQTL regulating SPE genes are predominantly located in heterozygous regions of the genome. Finally, we identify an SPE gene that regulates lateral root density in hybrids. Remarkably, the activity of this gene depends on the presence of a Mo17 allele in an eQTL that regulates this gene. Conclusions Here we show that dominance of SPE genes influences the number of active genes in hybrids, while heterozygosity is instrumental for the regulation of these genes. This finding supports the notion that the genetic constitution of distant regulatory elements is instrumental for the activity of heterosis-associated genes. In summary, our results connect genetic variation at regulatory loci and the degree of heterozygosity with phenotypic variation of heterosis via SPE complementation.

Our paper by Marion Pitz and Jutta Baldauf on the regulation of gene expression complementation in maize hybrids has now been published in Genome Biology. 1/7
genomebiology.biomedcentral.com/articles/10....

A new issue of CSH Protocols is out!

The cover image highlights the work by Marcon,
@hochholdingerf.bsky.social et al,who provide a detailed protocol for Mu-Seq, an approach to identify and map mutations in Mu-tagged insertional mutagenesis populations in maize.

⬇️Links below

Could all reviewers please be as kind as reviewer 1?

Congratulations to Michaela Matthes for successfully completing her habilitation.🎉🍾👏

Me: "What did you learn at journal club today?"

Intern: "That one day I'm going to publish a paper, and a bunch of people are going to sit around a table and rip it apart."

Map of China with pins indicating labs that received BonnMu stocks.

Map of Europe with pins indicating labs that received BonnMu stocks.

Map of America with pins indicating labs that received BonnMu stocks.

We have sent sequence indexed BonnMu maize 🌽 stocks to 130 labs worldwide. See their location on the maps below. 👇

Congratulations to Marion Pitz for successfully completing her PhD 🎉💐🍾

He retired from FIBL at 67. Regular retirement age in🇨🇭 is 65.

Ready to move!

no, maybe around 5. Mainly from Pakistan, India, African countries.

376 applications for a single PhD position in my lab that was only advertised via the website of @plantsciencedbg.bsky.social
😳

ChatGPT: please write an email for me to the admission committee

Pro tip: always delete the ChatGPT prompt before sending your motivation letter for a position in my group.

#PlantSciJobs #PlantSciJob
PhD position: systemic modulation of #maize root system architecture by seminal roots to adapt to #drought
In Frank @hochholdingerf.bsky.social ‘s lab @unibonn.bsky.social

www.deutsche-botanische-gesellschaft.de/en/job-openi...

A man is standing on a Stocherkahn in the Neckar river in Tübingen on a sunny day

We are happy to join the #plantscience community here in BlueSky!
Follow us to know more about our research at the ZMBP @unituebingen.bsky.social in beautiful Tübingen

Welcome in Bonn Boas!

🔬 An image competition was organised at the Biologists @ 100 conference in Liverpool. The extraordinary image of the mature leaf epidermis of Brachypodium by Lea Berg @lbmountain.bsky.social is one of 15 finalists 🏆 in the Company of Biologist's @focalplane.bsky.social competition.👏
#Biologists100

🔬 Maize embryo at 8 days after pollination, prepared by Dr Guojing Jiang, University of Regensburg.
💡 Plant embryogenesis is the process by which embryos develop from the fertilized zygote, involving the establishment of apical-basal polarity, meristem initiation, and lateral organ formation.

Maizegdb: die Maize Genetics and Genomics Datenbank ist essentiell für alle, die im Bereich der Mais 🌽 Genetik/Genomik/Züchtung arbeiten. Finanziert vom USDA, United States Department of Agriculture.
www.maizegdb.org

Excited that this paper from my group is now out! 🥳 congrats to all the authors.

The auxin–PLETHORA 5 module regulates wood fibre development in Populus tomentosa - Nature Plants The study reveals that PLETHORA 5, a transcription factor activated by auxin signalling in the vascular cambium, regulates cell expansion and cell wall thickening of fibres by directly repressing SND1...

Great paper by the group of lab alumnus Changzheng Xu on auxin regulation of fiber development in poplar.

www.nature.com/articles/s41...

The maize collaborator award is now on display in my office together with some #MGM2025 memorabilia and the two awesome books by Helen Anne Curry that just arrived. Everything is guarded by Gregor Mendel.

Finally time to celebrate our maize genetics collaborator award together with Caroline and the lab.