Figure 1.

PDCD2L variant and knockout mouse strategy. A) Homozygous mutations within the PDCD2L gene were found in two brothers presenting with type II globozoospermia. B) The variant found in both brothers affects a moderately conserved leucine residue in the Programmed cell death protein 2, C-terminal domain (PDCD2_C; InterPro: IPR007320). C) Splice prediction models predict the introduction of a splice donor site in exon 4. The image depicts the border between exon 4 (highlighted by a blue box) and intron 4 in the wildtype (reference) PDCD2L sequence (top) and in the mutated situation (bottom). The site of the variant found in the two brothers is indicated in red. Hits from the four different splice prediction models (SpliceSiteFinder-like, MaxEntScan, NNSPLICE, GeneSplicer and Human Splicing Finder) are displayed as blue and green vertical bars for 5′ (donor) sites and 3′ (acceptor) sites, respectively. The computed score of each model is presented by the height of the green and blue vertical bars as a proportion of the maximum possible score and the individual scores are displayed left of the bars. The four splicing prediction models predict the introduction of a novel splice donor site within exon 4, without strongly disrupting the wildtype (reference) splice donor site. The ortholog alignment and splicing prediction was done by the Alamut Visual version 2.13 software package (http://www.interactive-biosoftware.com). D) Mouse Pdcd2l generates four transcripts, encoding two proteins at 39 and 30 kDa, as well as two untranslated transcripts. E) Pdcd2l knockout mouse strategy, with guide RNAs targeting exons 1-3.