title: Cytogenetic analysis of experimental hybrids in species of Triatominae (Hemiptera-Reduviidae).
abstract: A cytogenetic analysis was performed in experimental hybrids between species of Chagas disease transmitting bugs with remarkable differences in the amount and distribution of heterochromatin. Using C-banding technique, we identified the parental species chromosomes and analysed the meiotic behaviour in the male hybrids between Triatoma platensis and T. infestans, T. platensis and T. delpontei, and T. infestans and T. rubrovaria. The two former hybrids have an entirely normal meiotic behaviour despite the extensive differences in C-banded karyotypes observed in the parental species, indicating that heterochromatin differences between homeologous chromosomes are not a barrier that influences meiotic synapsis and recombination. On the contrary, the experimental hybrids between T. infestans and T. rubrovaria show failures in pairing of homeologous chromosomes that lead to the production of abnormal spermatids and hybrid sterility. Our data suggest that karyotypic repatterning within triatomines has involved at least two different pathways. Among closely related species, chromosomal changes have largely involved addition or deletion of heterochromatic regions. In more distant species, chromosomal rearrangements (i.e. inversions and translocations) have also arisen. Hybridisation data also allow to hypothesize about the origin and divergence of this taxonomic group, as well as the mechanisms that maintain species isolation.
authors.affiliation: Sección Genética Evolutiva, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay. rperez@fcien.edu.uy
authors.forename: Ruben
authors.initials: R
authors.lastname: Pérez
authors.forename: Martín
authors.initials: M
authors.lastname: Hernández
authors.forename: Om
authors.initials: O
authors.lastname: Quintero
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Scvortzoff
authors.forename: Delmi
authors.initials: D
authors.lastname: Canale
authors.forename: Leticia
authors.initials: L
authors.lastname: Méndez
authors.forename: Claudia
authors.initials: C
authors.lastname: Cohanoff
authors.forename: Mariana
authors.initials: M
authors.lastname: Martino
authors.forename: Francisco
authors.initials: F
authors.lastname: Panzera
mesh_terms: D000818:Animals; D014355:Chagas Disease / Q000635:transmission; D002871:Chromosome Banding; D003582:Cytogenetics; D005260:Female; D006570:Heterochromatin / Q000235:genetics; D006801:Humans; D006824:Hybridization, Genetic; D007248:Infertility, Male / Q000235:genetics; D007303:Insect Vectors / Q000235:genetics / Q000469:parasitology; D007621:Karyotyping; D008297:Male; D008540:Meiosis / Q000235:genetics; D013045:Species Specificity; D014225:Triatominae / Q000145:classification / Q000235:genetics* / Q000469:parasitology; D014349:Trypanosoma cruzi
chemical_list: D006570:Heterochromatin