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Genome rearrangements and pervasive meiotic drive cause hybrid infertility in fission yeast.

Zanders SE, Eickbush MT, Yu JS, Kang JW, Fowler KR, Smith GR, Malik HS - Elife (2014)

Bottom Line: Hybrid sterility is one of the earliest postzygotic isolating mechanisms to evolve between two recently diverged species.Two of these driving loci are linked by a chromosomal translocation and thus constitute a novel type of paired meiotic drive complex.Our study reveals how quickly multiple barriers to fertility can arise.

View Article: PubMed Central - PubMed

Affiliation: Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.

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Related in: MedlinePlus

Sk has a reciprocal translocation between chromosomes 2 and 3.The translocation likely occurred as homologous recombination between repetitive elements. (A) Scaled schematic illustrating the location of the two full-length transposons in Sk where the translocation occured, shown as dashed vertical lines at positions 676,281 and 1,932,034 on the Sp chromosomes. The position on chr2 marks the start of a single LTR also found in Sp. Several genetic markers, two (of many) essential genes within the translocated segments, the centromeres (thick colored vertical lines), and the locations of PCR oligos (numbered 1–4) used to verify the translocation are shown. (B) The translocation junction was verified using PCR: ethidium bromide stained gel of PCR products using the indicated oligos on Sk and Sp DNA templates. Oligo pairs 1+2 and 3+4 produce a band in Sp, but not Sk. Oligo pairs 1+3 and 2+4 produce a band in Sk, but not Sp. The larger size of the Sk bands corresponds to the presence of a transposon at each location in Sk, but not in Sp. We believe the smaller bands in the Sk lanes are artefacts of PCR amplification across transposons because we see them even when we PCR across known Sp transposons.DOI:http://dx.doi.org/10.7554/eLife.02630.022
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fig4s5: Sk has a reciprocal translocation between chromosomes 2 and 3.The translocation likely occurred as homologous recombination between repetitive elements. (A) Scaled schematic illustrating the location of the two full-length transposons in Sk where the translocation occured, shown as dashed vertical lines at positions 676,281 and 1,932,034 on the Sp chromosomes. The position on chr2 marks the start of a single LTR also found in Sp. Several genetic markers, two (of many) essential genes within the translocated segments, the centromeres (thick colored vertical lines), and the locations of PCR oligos (numbered 1–4) used to verify the translocation are shown. (B) The translocation junction was verified using PCR: ethidium bromide stained gel of PCR products using the indicated oligos on Sk and Sp DNA templates. Oligo pairs 1+2 and 3+4 produce a band in Sp, but not Sk. Oligo pairs 1+3 and 2+4 produce a band in Sk, but not Sp. The larger size of the Sk bands corresponds to the presence of a transposon at each location in Sk, but not in Sp. We believe the smaller bands in the Sk lanes are artefacts of PCR amplification across transposons because we see them even when we PCR across known Sp transposons.DOI:http://dx.doi.org/10.7554/eLife.02630.022

Mentions: Our analyses of recombination also revealed a surprising genetic linkage between leu1 and ade6 in Sk/Sp hybrids, despite the fact that these genes are located on chromosomes 2 and 3, respectively, in both species (Figure 4B, Figure 4—figure supplement 2). We speculated that there was a reciprocal translocation between Sk chromosomes 2 and 3, relative to Sp. If such a translocation included essential genes, it would render gametes with non-parental chromosome combinations of the affected arms inviable; this inviability would also create the semblance of genetic linkage between the two chromosomes. Consistent with this possibility, we found using Southern blot analyses that essential genes (alr2 and SPCP1E11.08) had swapped chromosome locations between Sk and Sp (Figure 4B,C; Kim et al., 2010). We partially assembled the Sk genome to map the translocation junctions to position 676,281 on Sp chromosome 2 and 1,932,034 on Sp chromosome 3. We verified the translocation junctions via PCR (Figure 4—figure supplement 5). Analyses of synteny in two outgroup species (S. octosporus and S. cryophilus; Rhind et al., 2011) showed that the translocation occurred in the Sk lineage. The translocation appears to have resulted from a crossover between a Tf transposon found in Sk on chromosome 2 (corresponding to a single Tf transposon LTR in Sp) and a Tf transposon unique to Sk on chromosome 3.


Genome rearrangements and pervasive meiotic drive cause hybrid infertility in fission yeast.

Zanders SE, Eickbush MT, Yu JS, Kang JW, Fowler KR, Smith GR, Malik HS - Elife (2014)

Sk has a reciprocal translocation between chromosomes 2 and 3.The translocation likely occurred as homologous recombination between repetitive elements. (A) Scaled schematic illustrating the location of the two full-length transposons in Sk where the translocation occured, shown as dashed vertical lines at positions 676,281 and 1,932,034 on the Sp chromosomes. The position on chr2 marks the start of a single LTR also found in Sp. Several genetic markers, two (of many) essential genes within the translocated segments, the centromeres (thick colored vertical lines), and the locations of PCR oligos (numbered 1–4) used to verify the translocation are shown. (B) The translocation junction was verified using PCR: ethidium bromide stained gel of PCR products using the indicated oligos on Sk and Sp DNA templates. Oligo pairs 1+2 and 3+4 produce a band in Sp, but not Sk. Oligo pairs 1+3 and 2+4 produce a band in Sk, but not Sp. The larger size of the Sk bands corresponds to the presence of a transposon at each location in Sk, but not in Sp. We believe the smaller bands in the Sk lanes are artefacts of PCR amplification across transposons because we see them even when we PCR across known Sp transposons.DOI:http://dx.doi.org/10.7554/eLife.02630.022
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4066438&req=5

fig4s5: Sk has a reciprocal translocation between chromosomes 2 and 3.The translocation likely occurred as homologous recombination between repetitive elements. (A) Scaled schematic illustrating the location of the two full-length transposons in Sk where the translocation occured, shown as dashed vertical lines at positions 676,281 and 1,932,034 on the Sp chromosomes. The position on chr2 marks the start of a single LTR also found in Sp. Several genetic markers, two (of many) essential genes within the translocated segments, the centromeres (thick colored vertical lines), and the locations of PCR oligos (numbered 1–4) used to verify the translocation are shown. (B) The translocation junction was verified using PCR: ethidium bromide stained gel of PCR products using the indicated oligos on Sk and Sp DNA templates. Oligo pairs 1+2 and 3+4 produce a band in Sp, but not Sk. Oligo pairs 1+3 and 2+4 produce a band in Sk, but not Sp. The larger size of the Sk bands corresponds to the presence of a transposon at each location in Sk, but not in Sp. We believe the smaller bands in the Sk lanes are artefacts of PCR amplification across transposons because we see them even when we PCR across known Sp transposons.DOI:http://dx.doi.org/10.7554/eLife.02630.022
Mentions: Our analyses of recombination also revealed a surprising genetic linkage between leu1 and ade6 in Sk/Sp hybrids, despite the fact that these genes are located on chromosomes 2 and 3, respectively, in both species (Figure 4B, Figure 4—figure supplement 2). We speculated that there was a reciprocal translocation between Sk chromosomes 2 and 3, relative to Sp. If such a translocation included essential genes, it would render gametes with non-parental chromosome combinations of the affected arms inviable; this inviability would also create the semblance of genetic linkage between the two chromosomes. Consistent with this possibility, we found using Southern blot analyses that essential genes (alr2 and SPCP1E11.08) had swapped chromosome locations between Sk and Sp (Figure 4B,C; Kim et al., 2010). We partially assembled the Sk genome to map the translocation junctions to position 676,281 on Sp chromosome 2 and 1,932,034 on Sp chromosome 3. We verified the translocation junctions via PCR (Figure 4—figure supplement 5). Analyses of synteny in two outgroup species (S. octosporus and S. cryophilus; Rhind et al., 2011) showed that the translocation occurred in the Sk lineage. The translocation appears to have resulted from a crossover between a Tf transposon found in Sk on chromosome 2 (corresponding to a single Tf transposon LTR in Sp) and a Tf transposon unique to Sk on chromosome 3.

Bottom Line: Hybrid sterility is one of the earliest postzygotic isolating mechanisms to evolve between two recently diverged species.Two of these driving loci are linked by a chromosomal translocation and thus constitute a novel type of paired meiotic drive complex.Our study reveals how quickly multiple barriers to fertility can arise.

View Article: PubMed Central - PubMed

Affiliation: Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.

Show MeSH
Related in: MedlinePlus