Constitutive heterochromatin heteromorphism in the Neotropical armored catfish Hypostomus regani (Ihering, 1905) (Loricariidae, Hypostominae) from the Paraguay River basin (Mato Grosso do Sul, Brazil)

Autor: Greicy Ellen de Brito Ferreira, Ligia Magrinelli Barbosa, Ana Camila Prizon-Nakajima, Suzana de Paiva, Margarida Maria de Rossi Vieira, Raquel Bozini Gallo, Luciana Andreia Borin-Carvalho, Renata de Rosa, Claudio Henrique Zawadzki, Isabel Cristina Martins-Santos, Ana Luiza de Brito Portela-Castro
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Comparative Cytogenetics, Vol 13, Iss 1, Pp 27-39 (2019)
Druh dokumentu: article
ISSN: 1993-078X
1993-0771
DOI: 10.3897/CompCytogen.v13i1.30134
Popis: A cytogenetic analysis based on the integration of a number of different chromosomal methodologies, including chromosome microdissection was carried out to characterize the chromosomally polymorphic Hypostomus regani population from the Paraguay River basin, state of Mato Grosso do Sul in Brazil. All specimens had 2n=72 (FN=116) but two distinct karyotype formulas: karyomorph A (12m+14sm+18s+28a) and karyomorph B (13m+14sm+17st+28a). Karyomorph A and B differed only for pair 19 that consisted of two subtelocentrics in karyomorph A and a large metacentric and a subtelocentric in karyomorph B. This heteromorphism was due to extensive heterochromatinization of the short arm of the large metacentric, as highlighted by C-banding. The microdissection of the large metacentric of pair 19 allowed the production of a probe, named HrV (Hypostomus regani Variant), that hybridized to the whole p arm of the large metacentric and the pericentromeric region of the short arm of its (subtelocentric) homologue (karyomorph B) and of both homologs of pair 19 in karyomorph A. Additional cytogenetic techniques (FISH with 18S and 5S rDNA probes, CMA3 and DAPI staining) allowed a finer distinction of the two karyomorphs. These results reinforced the hypothesis that the novel large metacentric of H. regani (karyomorph B) was the result of the amplification of heterochromatin segments, which contributed to karyotypic diversification in this species.
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