Long‐term monitoring of B‐chromosome invasion and neutralization in a population of Prospero autumnale (Asparagaceae) |
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Authors: | Pedro Lanzas Francisco Perfectti Manuel A Garrido‐Ramos Carmelo Ruíz‐Rejón Mónica González‐Sánchez María Puertas Juan Pedro M Camacho |
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Institution: | 1. Departamento de Genética, Universidad de Granada, 18071 Granada, Spain;2. Unidad de Excelencia “Modeling Nature”, Universidad de Granada, 18071 Granada, Spain;3. Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain |
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Abstract: | B chromosomes have been reported in about 15% of eukaryotes, but long‐term dynamics of B chromosomes in a single natural population has rarely been analyzed. Prospero autumnale plants collected in 1981 and 1983 at Cuesta de La Palma population had shown the presence of B chromosomes. We analyze here seven additional samples collected between 1987 and 2015, and show that B frequency increased significantly during the 1980s and showed minor fluctuations between 2005 and 2015. A mother–offspring analysis of B chromosome transmission, at population level, showed significant drive on the male side (kB = 0.65) and significant drag on the female side (kB = 0.33), with average B transmission rate being very close to the Mendelian rate (0.5). No significant effects of B chromosomes were observed on a number of vigor and fertility‐related traits. Within a parasite/host framework, these results suggest that B chromosomes’ drive on the male side is the main pathway for B chromosome invasion, whereas B chromosome drag on the female side might be the main manifestation of host genome resistance in this species. Prospero autumnale thus illuminates a novel evolutionary pathway for B chromosome neutralization by means of a decrease in B transmission through the nondriving sex. |
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Keywords: | B‐chromosomes drag drive invasion neutralization |
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