title: Localization of alkali-labile sites in donkey (Equus asinus) and stallion (Equus caballus) spermatozoa.
abstract: The presence of constitutive alkali-labile sites (ALS) has been investigated using a protocol of DNA breakage detection-fluorescence in situ hybridization and comet assay in spermatozoa of donkey (Equus asinus) and stallion (Equus caballus). These results were compared with those obtained using a similar experimental approach using somatic cells. The relative abundance of ALS was of the order of four times more in spermatozoa than in somatic cells. Alkali-labile sites showed a tendency to cluster localized at the equatorial-distal regions of the sperm. The amount of hybridized signal in the ALS in the sperm of donkey (Equus asinus) was 1.3 times greater than in stallion (Equus caballus), and the length of the comet tail obtained in donkey sperm was 1.6 times longer than that observed in stallion (P < 0.05); however, these differences were not appreciated in somatic cells. In conclusion, ALS localization in sperm is not a randomized event and a different pattern of ALS distribution occurs for each species. These results suggest that ALS represents a species-specific issue related to chromatin organization in sperm and somatic cells in mammalian species, and they might diverge even with very short phylogenetic distances.
authors.affiliation: Departamento de Genética, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social (IMSS), Monterrey, Nuevo León, México. Electronic address: elvacortes@cibinmty.net.
authors.forename: Elva I
authors.initials: EI
authors.lastname: Cortés-Gutiérrez
authors.affiliation: Departamento de Genética, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social (IMSS), Monterrey, Nuevo León, México.
authors.forename: Martha I
authors.initials: MI
authors.lastname: Dávila-Rodríguez
authors.affiliation: Departamento de Biología, Unidad de Genética, Universidad Autónoma de Madrid (UAM), Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: López-Fernández
authors.affiliation: Unidad de Genética, Unit, INIBIC, Complejo Hospitalario Universitario A Coruña, La Coruña, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Fernández
authors.affiliation: Servicios de Veterinaria de la Armada Española (FESCCR-Ministerio de Defensa), Ávila, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Crespo
authors.affiliation: Departamento de Biología, Unidad de Genética, Universidad Autónoma de Madrid (UAM), Madrid, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Gosálvez
mesh_terms: D000818:Animals; D020552:Comet Assay / Q000379:methods / Q000662:veterinary; D053960:DNA Breaks; D018397:Equidae / Q000235:genetics*; D006736:Horses / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods / Q000662:veterinary; D008297:Male; D013094:Spermatozoa
keywords: Alkali-labile sites; DNA breakage detection-FISH; Sperm DNA structure