The inactivation of <i>MSH2</i> increases the frequency of generation of cross-species hybrids.

<p>(A) Schematic map of the wild-type and inactivated <i>MSH2</i> alleles of <i>L</i>. <i>infantum</i>. (B) Southern blot analysis of gDNA derived from <i>L. infantum</i> WT (Lane 1), <i>L. infantum MSH2</i> haploid mutant (Lane 2) and <i>L. infantum MSH2</i> null mutant (Lane 3) digested with <i>Sac</i>I and hybridized with a probe specific for the 3′ UTR of <i>MSH2</i> (upper panel). The absence of <i>MSH2</i> gene was confirmed by PCR using a pair of internal primers of the gene (middle panel); and primers for the amplification of <i>LinJ34_V3.0540</i> were used as control (lower panel). Molecular weight is indicated on the left of the blot. (C–F) The number of recombinant clones obtained from 1×10⁸<i>L. infantum</i> 263 WT parasites (black bars), <i>L. infantum</i> Li263Δ<i>MSH2</i>::HYG:BLA (grey bars) and <i>L. infantum</i> Li263Δ<i>MSH2</i>::HYG:BLA complemented <i>in trans</i> for <i>MSH2</i> (white bars) transfected with a linear LinJ28_V3.0330:NEO DNA PCR fragment amplified from <i>L. infantum</i> (C), a linear LmjF30.1250:NEO (PK) DNA PCR fragment amplified from <i>L. major</i> (D), gDNA derived from <i>L. major</i> Friedlin LmΔ<i>LRP</i>::NEO/NEO (E), or gDNA derived from <i>L. major</i> Friedlin LmΔLmjF05.0610::NEO/LmjF05.0610 (F). The average of at least 3 experiments is indicated and the number of colonies is indicated per 10 µg of DNA.