Origin of the X1X1X2X2/X1X2Y sex chromosome system of Harttia punctata (Siluriformes, Loricariidae) inferred from chromosome painting and FISH with ribosomal DNA markers

Abstract

Harttia is a genus in the subfamily Loricariinae that accommodates fishes popularly known as armored catfishes. They show extensive karyotypic diversity regarding interspecific numerical/structural variation of the karyotypes, with the presence of the XX/XY1Y2 multiple sex chromosome system, as found in H. carvalhoi. In this context, this study aimed to characterize Harttia punctata chromosomally, for the first time, and to infer the rearrangements that originated the X1X1X2X2/X1X2Y multiple sex chromosome system present in this species. The data obtained in this study, with classical (Giemsa, C-banding and AgNORs) and molecular methodologies (fluorescence in situ hybridization) and chromosome microdissection, indicated that a translocation between distinct acrocentric chromosomes bearing rRNA genes, accompanied by deletions in both chromosomes, might have originated the neo-Y chromosome in this species. The data also suggest that the multiple sex chromosome systems present in H. carvalhoi and H. punctata had an independent origin, evidencing the recurrence of chromosome alterations in species from this genus.

Cytogenetic analysis of two locariid species (Teleostei, Siluriformes) from Iguatemi River (Parana River drainage) in Brazil

“…Others species previously analyzed of Loricariinae as Harttia kronei Miranda Ribeiro, 1908, Rineloricaria kronei (Miranda Ribeiro, 1911), Rineloricaria cadeae (Hensel, 1868), Rineloricaria n. sp., Harttia loricariformis Steindachner, 1877 (Alves et al 2003) and Harttia punctata Rapp Py-Daniel & Oliveira, 2001 (Blanco et al 2014) also presented two NOR-bearing chromosomes, but located on the short arm, except the Harttia loricariformis and Harttia punctata that presented NOR interstitial on the long arm.…”

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

“…The rRNA in eukaryotes presents as two subunits (one formed by 28S, 18S and 5.8S and another one formed by 5S) and their DNA sequences vary very slowly due to selective pressure, being considered highly conserved (Long and Dawid 1980). This allows the interspecific hybridization of the mentioned probes (obtained from Prochilodus argenteus and Megaleporinus elongatus ), with chromosomes of a wide variety of fishes, like Characiformes (de Marco Ferro et al 2001, Pazza et al 2006, da Silva et al 2016), Gymnotiformes (Fernandes et al 2017a, 2017b) Perciformes (Jacobina et al 2014, Argôlo and Affonso 2015, Oliveira et al 2015b), Siluriformes (Blanco et al 2014, Kantek et al 2015, Ribeiro et al 2015), including other species of Hypostomus (Kavalco et al 2004a, 2005, Traldi et al 2013, Baumgärtner et al 2014, Oliveira et al 2015a, Lara Kamei et al 2017). …”

Interspecific cytogenetic relationships in three Acestrohynchus species (Acestrohynchinae, Characiformes) reveal the existence of possible cryptic species

“…The comparison of the different markers provides valuable insights into the chromosomal differentiation of Acestrorhynchus. In karyotypes of all species, the blocks of constitutive heterochromatin are located primarily in centromeric or telomeric regions, although large heterochromatic blocks are associated with the NORs, as seen as in most species of teleost fish of different families of different orders such as Anguilliformes, Siluriformes, Characiformes, among others (Gornung 2013;Blanco et al 2014;Salvadori et al 2018). The NOR phenotype was simple, i.e.…”