title: Environmental factors shape the community of symbionts in the hoopoe uropygial gland more than genetic factors.
abstract: Exploring processes of coevolution of microorganisms and their hosts is a new imperative for life sciences. If bacteria protect hosts against pathogens, mechanisms facilitating the intergenerational transmission of such bacteria will be strongly selected by evolution. By disentangling the diversity of bacterial strains from the uropygium of hoopoes (Upupa epops) due to genetic relatedness or to a common environment, we explored the importance of horizontal (from the environment) and vertical (from parents) acquisition of antimicrobial-producing symbionts in this species. For this purpose, we compared bacterial communities among individuals in nonmanipulated nests; we also performed a cross-fostering experiment using recently hatched nestlings before uropygial gland development and some nestlings that were reared outside hoopoe nests. The capacity of individuals to acquire microbial symbionts horizontally during their development was supported by our results, since cross-fostered nestlings share bacterial strains with foster siblings and nestlings that were not in contact with hoopoe adults or nests also developed the symbiosis. Moreover, nestlings could change some bacterial strains over the course of their stay in the nest, and adult females changed their bacterial community in different years. However, a low rate of vertical transmission was inferred, since genetic siblings reared in different nests shared more bacterial strains than they shared with unrelated nestlings raised in different nests. In conclusion, hoopoes are able to incorporate new symbionts from the environment during the development of the uropygium, which could be a selective advantage if strains with higher antimicrobial capacity are incorporated into the gland and could aid hosts in fighting against pathogenic and disease-causing microbes.
authors.affiliation: Dpto. Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain Grupo Coevolución, Unidad asociada al CSIC, Universidad de Granada, Granada, Spain magda@eeza.csic.es.
authors.forename: Magdalena
authors.identifier: http://orcid.org/0000-0002-4202-5180
authors.initials: M
authors.lastname: Ruiz-Rodríguez
authors.affiliation: Dpto. Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain Grupo Coevolución, Unidad asociada al CSIC, Universidad de Granada, Granada, Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Soler
authors.affiliation: Grupo Coevolución, Unidad asociada al CSIC, Universidad de Granada, Granada, Spain Dpto. Zoología, Universidad de Granada, Granada, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Martín-Vivaldi
authors.affiliation: Dpto. Microbiología, Universidad de Granada, Granada, Spain.
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Martín-Platero
authors.affiliation: Dpto. Biología de la Conservación, Estación Biológica de Doñana (EBD-CSIC), Seville, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Méndez
authors.affiliation: Dpto. Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain Dpto. Microbiología, Universidad de Granada, Granada, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Peralta-Sánchez
authors.affiliation: Dpto. Microbiología, Universidad de Granada, Granada, Spain.
authors.forename: Samir
authors.initials: S
authors.lastname: Ananou
authors.affiliation: Grupo Coevolución, Unidad asociada al CSIC, Universidad de Granada, Granada, Spain Dpto. Microbiología, Universidad de Granada, Granada, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Valdivia
authors.affiliation: Grupo Coevolución, Unidad asociada al CSIC, Universidad de Granada, Granada, Spain Dpto. Microbiología, Universidad de Granada, Granada, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Martínez-Bueno
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification*; D058448:Biota; D001717:Birds / Q000382:microbiology* / Q000502:physiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D058889:Molecular Typing; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial