Long‐term monitoring of B‐chromosome invasion and neutralization in a population of Prospero autumnale (Asparagaceae). (1st June 2018)

• Record Type: Journal Article
• Authors: Lanzas, Pedro; Perfectti, Francisco; Garrido‐Ramos, Manuel A.; Ruíz‐Rejón, Carmelo; González‐Sánchez, Mónica; Puertas, María; Camacho, Juan Pedro M.
• Is Part Of: Evolution. Volume 72:Number 6(2018)
• Page Start: 1216
• Page End: 1224
• Publication Date: 2018-06-01
• Subjects: B‐chromosomes -- drag -- drive -- invasion -- neutralization; Evolution -- Periodicals; Heredity -- Periodicals; Évolution (Biologie) -- Périodiques; Hérédité -- Périodiques; 338.47004094
• DOI: 10.1111/evo.13501
• Languages: English
• ISSNs: 0014-3820

Abstract

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.