Fig. 1: Acrocentric chromosomes missegregate more often than metacentric chromosomes in porcine oocytes.

a, b Schematic representation of the labelling strategy with the pericentromeric TALEs in the porcine cells. The region recognised by each TALE is indicated for each chromosome type. TALEs are fused with a fluorescent protein. Labelled chromosomes are referred to as acro-labelled and meta-labelled, respectively. Blue, chromosomes; magenta, kinetochores; yellow, TALE; green, fluorescent protein, and TALE on chromosomes. c Representative immunofluorescence images of a spindle from a euploid and an aneuploid intact fixed metaphase II egg injected with the acrocentric-TALE, (bottom row). Numbers within the grey illustrations indicate the number of chromosomes in each of the two spindles (top row). Numbers next to the green illustrations indicate the number of acro-labelled chromosomes in both the euploid and aneuploid cells. The black arrowheads indicate the extra acro-labelled chromosome. Scale bar, 1 μm. Representative examples of 96 immunolabelled porcine eggs. d The fraction of aneuploid eggs from the total of analysed fixed metaphase II porcine eggs. Aneuploid eggs were identified by kinetochore counting (113 eggs analysed). e Frequency of missegregation for acro-labelled and meta chromosomes from the total chromosomes counted in each category. Counting was performed in fixed metaphase II porcine spindles injected with the acrocentric-TALE (96 eggs analysed). Two-sided Fisher’s exact test (p < 0.0001). f Proportion of euploid and aneuploid metaphase II porcine eggs after live-cell imaging. Euploidy status is determined by the correct or erroneous segregation outcome of the chromosomes during live imaging (48 eggs analysed). g Frequency of missegregation per chromosome group after live-cell imaging (48 eggs analysed). Two-sided Fisher’s exact test (acro-labelled/meta, p < 0.0001; acro-labelled/meta-labelled, p = 0.003). The number of chromosomes analysed is indicated in brackets under each category. P-values in the graphs are indicated as follows, ***p < 0.001 and ****p < 0.0001. The number of cells is indicated with N in the graph or in brackets in the figure legend.