title: Drosophila Females Undergo Genome Expansion after Interspecific Hybridization.
abstract: Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent.
authors.affiliation: Departament De Genètica I Microbiologia (Edifici C), Grup De Genòmica, Bioinformàtica I Biologia Evolutiva. Universitat Autònoma De Barcelona, Spain.
authors.forename: Valèria
authors.initials: V
authors.lastname: Romero-Soriano
authors.affiliation: Laboratoire De Biométrie Et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Burlet
authors.affiliation: Laboratorio De Genética Evolutiva, Pontificia Universidad Católica Del Ecuador, Quito, Ecuador.
authors.forename: Doris
authors.initials: D
authors.lastname: Vela
authors.affiliation: Departament De Genètica I Microbiologia (Edifici C), Grup De Genòmica, Bioinformàtica I Biologia Evolutiva. Universitat Autònoma De Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Fontdevila
authors.affiliation: Laboratoire De Biométrie Et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France.
authors.forename: Cristina
authors.initials: C
authors.lastname: Vieira
authors.affiliation: Departament De Genètica I Microbiologia (Edifici C), Grup De Genòmica, Bioinformàtica I Biologia Evolutiva. Universitat Autònoma De Barcelona, Spain mariapilar.garcia.guerreiro@uab.cat.
authors.forename: María Pilar
authors.initials: MP
authors.lastname: García Guerreiro
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements / Q000235:genetics*; D004330:Drosophila / Q000235:genetics*; D005260:Female; D059646:Genome Size; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D018626:Retroelements / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D018626:Retroelements
keywords: AFLP markers; Drosophila; flow cytometry; genome size; hybrids; transposable elements