Lia Kunz (Justus Liebig University Giessen)
Lia Kunz's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Justus Liebig University Giessen in the year 2026 with the title:
Annotation of single-nuclei transcriptome in fern Ceratopteris richardii using HCR fluorescence in situ hybridization
For the first time the tissue-specific gene expression in the gametophyte of the fern Ceratopteris richardii during fertilization could be shown in the model plant with the Hybridization Chain Reaction Fluorescence in situ Hybridization (HCR-FISH) technique.
Fern Ceratopteris richardii (C-fern) is a new model organism to study land plant evolution, especially related to reproduction. In ferns, the haploid (gametophyte) stage is few millimeters small and short-lived but produces egg and sperm cells.
To create a gene expression atlas that shows detailed maps of gene activity during development, the gametophyte was analyzed with RNA sequencing of single nuclei. The challenge: this analysis does not keep track of which tissues the nuclei come from.
To put all the pieces of the expression data “map“ together then, the technique HCR-FISH, based on fluorescence in situ hybridization, was applied in the whole gametophyte, mapping gene expression at mRNA level even in single cells.
Marker genes allowed orientation for mapping of different tissue types – including reproductive structures bearing egg or sperm cells.
This gene expression map helps in comparing gene activity of the independent gametophyte in ferns with the gene activity of the gametophyte in flowering plants, which is embedded in pollen and ovules. Important insights into evolution of land plant reproduction can thus be gained.
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Lia Kunz conducted this work at the Botany institute in the working group of Prof. Dr Annette Becker.
