title: Heterochromatin characterization of four fish species of the family Loricariidae (Siluriformes).
abstract: The karyotypic structures and the composition and distribution of the heterochromatin in the karyotypes of four catfish species belonging to four Loricariidae subfamilies were analysed, namely: Neoplecostomus microps (Neoplecostominae) with 2n=54 chromosomes, Harttia loricariformis (Loricariinae) with 2n=56 chromosomes, Hypostomus affinis (Hypostominae) with 2n=66 chromosomes and Upsilodus sp. (Upsilodinae) with 2n=96 chromosomes. The amount and composition of heterochromatin was quite unequal among the studied species, being copious and mainly GC-rich in Upsilodus sp. and scarce and balanced in H. loricariformis. All of the H. affinis heterochromatin is GC-rich and related with nucleolar organizing regions. N. microps show low quantity of interstitial and GC-rich heterochromatin, one of them being related with NORs. Trends in the macrokaryotypic diversification as well as in the distribution pattern of the heterochromatin are discussed.
authors.affiliation: Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil. kavalco@biociencia.org
authors.forename: Karine
authors.initials: K
authors.lastname: Frehner Kavalco
authors.forename: Rubens
authors.initials: R
authors.lastname: Pazza
authors.forename: Luiz Antonio Carlos
authors.initials: LA
authors.lastname: Bertollo
authors.forename: Orlando
authors.initials: O
authors.lastname: Moreira-Filho
mesh_terms: D000818:Animals; D001938:Brazil; D002397:Catfishes / Q000235:genetics*; D002875:Chromosomes / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D005260:Female; D005456:Fluorescent Dyes; D014644:Genetic Variation; D006570:Heterochromatin / Q000737:chemistry / Q000235:genetics*; D007211:Indoles; D007621:Karyotyping; D008297:Male
chemical_list: D005456:Fluorescent Dyes; D006570:Heterochromatin; D007211:Indoles; C007293:DAPI