Revealing chromosomal structure in trans-Andean Loricariidae: first cytogenetic characterization of the fish Lasiancistrus volcanensis
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| Autores: | , , , , , |
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| Formato: | artículo original |
| Estado: | Versión publicada |
| Data de Publicación: | 2026 |
| Descripción: | Introduction: The genus Lasiancistrus (Ancistrini) comprises four cis-Andean and five trans-Andean valid species distributed across trans-Andean, Amazonian, Orinoco, and Guianan drainages. No cytogenetic data are available for trans-Andean populations, limiting our understanding of their chromosomal organization and evolutionary history. Within Loricariidae, the only previous cytogenetic study in this region examined Transancistrus santarosensis from the Gulf of Guayaquil drainage, Ecuador. Objective: To present the first cytogenetic characterization of Lasiancistrus volcanensis, a species endemic to the trans-Andean Magdalena River basin, to describe its karyotype organization and explore its evolutionary implications within Loricariidae. Methods: Specimens were analyzed using Giemsa staining, C-banding, and fluorescence in situ hybridization (FISH) with CA(15) and CAA(10) microsatellite probes. Chromosome number, morphology, heterochromatin distribution, and microsatellite localization were determined. Results: The diploid number of L. volcanensis was of 2 n = 54 and a fundamental number of 108, with a karyotypic formula of 32 m + 18 sm + 4 st. Heterochromatic regions were concentrated in pericentromeric positions of several pairs, including large blocks on the first two pairs. Microsatellite signals were predominantly located in terminal chromosome regions. The predominance of meta- and submetacentric chromosomes, along with the conserved diploid number, supports the hypothesis of karyotypic stability in Loricariidae. Conclusions: These results expand the cytogenetic baseline for Loricariidae. The observed patterns suggest evolutionary conservatism in L. volcanensis. Broader cytogenetic and genomic surveys across its distribution are essential to elucidate the mechanisms underlying karyotype diversification in this species. |
| País: | Portal de Revistas UCR |
| Institución: | Universidad de Costa Rica |
| Repositorio: | Portal de Revistas UCR |
| Idioma: | Inglés |
| OAI Identifier: | oai:portal.revistas.ucr.ac.cr:article/1429 |
| Acceso en liña: | https://revistas.ucr.ac.cr/index.php/rrbt/article/view/1429 |
| Palabra crave: | chromosome evolution Hypostominae karyotype Magdalena River microsatellites evolución cromosómica cariotipo río Magdalena microsatélites |