Studies in two allopatric populations of Hypostomus affinis (Steindachner, 1877): the role of mapping the ribosomal genes to understand the chromosome evolution of the group

Abstract

Several cytogenetic markers show chromosomal diversity in the fish such as “armoured catfish”. Although studies have characterized many species in the major genera representing these Siluridae, particularly in the genus Hypostomus Lacépède, 1803, trends in chromosome evolution of this group remain unclear. The Paraíba do Sul river basin contains the armoured catfish Hypostomus affinis Steindachner, 1877, which is unique because of its distribution of repetitive DNAs, the 5S and 18S rDNA. Identified samples and registered collections in Brazilian museums were identified as the same typological species, while we observed wide variations in the physical location of this gene in the karyotype based on fluorescent in situ hybridization results. In this study, we propose that these species can represent evolutionarily independent units, as these fish frequently undergo processes such as dispersion and vicariance and that the rDNA is associated with DNA that spreads in the genome, such as transposons. Additionally, the absence of gene flow due to the distance of the sample location could intensify evolutionary processes. The phenotypes found for the 18S rDNA showed minor changes in relation to the number of sites between the lower and upper drainage regions of Paraíba do Sul. The large difference in the number of sites found for the 5S rDNA entered the same region (upper drainage of the basin) and the literature data could represent a population dynamics where an expansion of the 5S rDNA sites provides an extinct or non-sampled cytotype in this work.

Cytogenetic characterization of Hypostomus soniae Hollanda-Carvalho & Weber, 2004 from the Teles Pires River, southern Amazon basin: evidence of an early stage of an XX/XY sex chromosome system

“…One other ancestral trait in the Loricariidae is the existence of a chromosome pair with NORs, which has been described in a number of fish species (Artoni and Bertollo 1996; Alves et al 2005; Bueno et al 2014; Rubert et al 2016), including some species of the genus Hypostomus (Mendes-Neto et al 2011; Rubert et al 2011; Alves et al 2012). Multiple NORs, as observed in H. soniae in the present study, are considered to be a derived characteristic, and are the most common pattern in the genus Hypostomus (Rubert et al 2016; Brandão et al 2018). In the “ H. cochliodon group”, multiple NORs were noted in H. cochliodon from the Paraguay River basin (Rubert et al 2016), although Bueno et al (2014) observed a simple NOR in H. cochliodon individuals from the Paraná River basin.…”

Cytogenetic survey of eight ant species from the Amazon rainforest

“…The nomenclature of Levan et al (1964) is typically used for chromosomal classification of different organisms such as plants (Winterfeld et al 2018;Sadeghian et al 2019), spiders (Araújo et al 2020), beetles (Şendoğan and Alpagut-Keskin 2016), bees (Lopes et al 2021), wasps (Tavares and Teixeira 2021), velvet worms (reviewed by Duarte et al 2020), and fishes (Brandão et al 2018). Recent ant cytogenetic studies have focused on measurements of chromosomes (Barros et al 2010(Barros et al , 2014(Barros et al , 2016Cristiano et al 2013, 2017, Santos et al 2016, Micolino et al 2019, 2020Teixeira et al 2020).…”

The development of early monitoring tools to detect aquatic invasive species: eDNA assay development and the case of the armored catfish Hypostomus robinii

“…The species is also often referred to as the ‘armored catfish,’ due to its body coverage of bony plates (Nico et al, 2009). Despite its distinct appearance, genetic analysis is often required to confirm species identification due to the sheer diversity associated with this family (Brandão et al, 2018; Matamoros et al, 2016). This particular species is, however, extremely popular in the aquarium trade, and as such, there have been many documented releases into wild river systems (Cook‐Hildreth et al, 2016; Matamoros et al, 2016).…”