ALT Fig. 2. Genetic strategies in mouse fertility research. (A-C) The left panel illustrates the single-gene strategies discussed in the main text. These include: exploiting spontaneous mutant phenotypes (A), where the black extremities represent a visible morphological phenotype; targeted mutagenesis strategies, including CRISPR editing (B); and unbiased random ENU mutagenesis (C). (D-F) The right panel illustrates strategies that take advantage of genetically diverse strains of mice to detect genes controlling reproductive parameters. As discussed in the main text, the standard inbred strains (D) exhibit considerable diversity in quantitative parameters of gamete production and function. These strains can be interbred to form F1 hybrids (E), which often can identify dominant traits. Further intercrossing of hybrids (F) leads to bi-parental recombinant inbred strains and the multiparent strains with representation of several input genomes. See more at https://doi.org/10.1242/dev.201313