Evidence that guppy LG12 genes behave as sex-linked in M. picta. The table shows genotypes in M. picta for variants in loci on the guppy sex chromosome, LG12 (microsatellite markers and variants in the zer1 and fpgs genes).

Sibships were harvested from gravid females sampled in the wild from natural populations in Trinidad (family numbers T1 to T7) and Suriname (families S1 to S3). The positions of the markers genotyped in the female guppy genome assembly are indicated below the marker names. Tissue from the female parent was used to genotype the mother. Using the microsatellite loci, the progeny were inferred to be male when all loci with variants in the family have only a single one of the dam’s X-linked alleles, consistent with hemizygosity of the X chromosome in males. Although the data for these loci are limited, the genotypes were consistent with sex linkage in all families in which they were informative. The X-linked alleles of the fathers at each locus were then deduced from the genotypes of female progeny. These data indicated that many sibships were sired by multiple males; the sires of most female progeny could be assigned. The dam and inferred sire genotypes are shown first for each family, with the observed progeny genotypes below. For the zer1 genes, males were not hemizygous, allowing us to determine the sire for some male progeny. Two progeny each had genotypes for one microsatellite marker (highighted in yellow) that do not completely correspond to our inferences based on the other markers; in both cases, the allele sizes were only 2 bp different from another allele in the family, and could have been mis-classified. (XLSX)