Extended Data Fig. 3: Recombination in gametes and heterozygosity distribution in the wild on chromosomes 2 and 4.

(A-B) Number of recombinations in oocytes and sperm on chromosomes 2 and 4 summarized as a violin plot (A) and a box plot (B). The median number of recombinations on chromosome 2 is 3 for sperm and 2 for oocytes, derived from a total of 49 sperm and 38 oocytes. The median number of recombinations on chromosome 4 is 2 for sperm and 1 for oocytes, derived from a total of 50 sperm and 26 oocytes. Chr2 sperm: min = 0, max = 7, median = 3, first quartile = 2, third quartile = 4. Chr2 oocytes: min = 0, max = 7, median = 2, first quartile = 0, third quartile = 4; Chr4 sperm: min = 0, max = 7, median = 2, first quartile = 1, third quartile = 4; Chr4 oocytes: min = 0, max = 3, median = 1, first quartile = 1, third quartile = 2. (C-D) Very few sites are consistently heterozygous in more than 80% of the wild isolates on chromosomes 2 and 4 in Sicily (C) and in Sardinia (D).