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Biology subjects

Kraemer, F.

Publications and source records attributed to Kraemer, F..

2 recordsLinked to original sources

Sixteen isotropic 3D fluorescence live imaging datasets of Tribolium castaneum gastrulation

Gastrulation is a pivotal phase of early embryogenesis during which initially uniform cells undergo coordinated movements and fate specification to establish the basic body plan. Although previous studies have advanced our understanding of gastrulation in the red flour beetle Tribolium castaneum, quantitative morphogenetic data remain limited. Here, we present the second Systematic Live Imaging Collection of Embryogenesis (SLICE-2), consisting of sixteen isotropic 3D fluorescence live imaging datasets that document Tribolium gastrulation and early germband elongation. Imaging was performed using light sheet fluorescence microscopy in conjunction with a homozygous transgenic line that expresses mEmerald-labeled nanobodies against histone H2A/H2B. Embryos were recorded along four orientations, and the resulting axial image stacks were subjected to multiview fusion to obtain isotropic 3D images of entire embryos with reduced shadowing artifacts. Datasets are provided as weighted-average fusion and fusion-deconvolution derivatives, and nuclei segmentation data are available for selected datasets and stages. SLICE-2 expands the resource arsenal for Tribolium, enabling comprehensive analyses of gastrulation dynamics and providing benchmark data for image processing, segmentation, and modeling approaches.

developmental biology↗

Marker-based knockout genotyping in diploid model organisms

Analysis of gene function in diploid organisms typically relies on molecular methods to distinguish wild-type, mono-allelic knockout, and bi-allelic knockout individuals, creating a major practical bottleneck for large-scale developmental studies. Here, we establish a modular visual genotyping approach that enables organism-level discrimination of knockout zygosity by tagging alternative disrupted alleles with spectrally distinct fluorescent markers. Implemented in the red flour beetle Tribolium castaneum, a two-marker strategy permits reliable identification of bi-allelic knockouts within mixed cohorts in a semi-random insertional mutagenesis framework. Further, a four-marker strategy using a targeted CRISPR/Cas9-based gene editing approach enables systematic generation and unambiguous recognition of individuals homozygous for both a disrupted gene of choice and a fluorescent reporter transgene. This design substantially reduces the workload associated with routine molecular genotyping while enabling genotype-resolved long-term live imaging of embryonic morphogenesis. Application to the extra-embryonic specification factor zerknullt 1 reveals haplosufficiency and a semi-lethal phenotype associated with variable morphogenetic outcomes. Together, our approach provides a scalable framework for functional analysis of essential developmental genes. Summary StatementVisual marker-based genotyping enables organism-level discrimination of knockout zygosity, reducing reliance on molecular assays and facilitating scalable, genotype-resolved live imaging of developmental gene function in diploid model organisms.

genetics↗