Figure 5. Fine-scale mapping of sperm midpiece length.

F₂ hybrid males (n=11) that showed a recombination event in the 1.5 LOD support interval associated with the midpiece QTL (see Fig. 3); males are sorted by mean midpiece length (μm) shown by grey circles (n=10 males, n=10 sperm/male) from shortest (top) to longest (bottom). Mean±s.e. midpiece length for pure P. polionotus, P. maniculatus (redrawn from Fig. 1) and F₁ hybrids are shown for reference. Genotypes for each individual at nine markers: Aa denotes heterozygous genotypes for the P. maniculatus and P. polionotus alleles, ‘aa' for homozygous P. polionotus alleles. Red box highlights the Prkar1a genotype that shows a perfect association with midpiece length variation unlike neighboring loci.