First cytogenetic characterization of the sub-arctic marine fish Mallotus villosus (Müller, 1776), Osmeriformes, Osmeridae

Abstract

The capelin, Mallotus villosus (Osmeriformes, Osmeridae), is an ecological and commercial key component of the sub-arctic ichthyofauna. Here, we provide the first cytogenetic information on the species based on both conventional karyotyping and chromosomal mapping of 45S and 5S ribosomal genes through fluorescence in situ hybridization (FISH). The capelin genome displayed a diploid number of 54 with the karyotypic formula 26m/sm+28st/a and a fundamental number (FN) = 80. Both classes of ribosomal genes appeared to be spread out to multiple chromosomal locations, i.e. the 45S and 5S rDNA clusters were detected on six and seven chromosome pairs, respectively. A linked chromosomal organization of the major and minor ribosomal genes classes has been visualized in most of the rDNAs chromosomal locations. A comparative analysis of the available cytogenetic data for the family Osmeridae reveals diploid numbers higher than 48 and high fundamental numbers. This suggests that a rearranged karyotype is a shared feature within this family.

Molecular Cytogenetic Analysis of the European Hake Merluccius merluccius (Merlucciidae, Gadiformes): U1 and U2 snRNA Gene Clusters Map to the Same Location

“…Chromosomal mapping of ribosomal RNA genes has been performed in many species of fishes [ 15 – 17 , 20 – 22 , 24 , 26 , 31 – 36 , 49 – 54 ]. The presence of signals at a single location in one chromosome pair for the 45S rDNA in M .…”

“…Regarding the 5S rDNA [ 15 , 16 , 20 – 22 , 24 , 26 , 31 – 36 , 49 , 50 , 52 – 54 ], while some fish species show signals restricted to one chromosome pair, in others the signals appear in many or almost all chromosome pairs [i.e. 49 , 53 , 54 ]. The Atlantic cod, the only other gadoid studied to date, show signals at subterminal regions on the short arms of six pairs of chromosomes [ 26 ].…”

Inter-population differences in otolith morphology are genetically encoded in the killifish <i>Aphanius fasciatus</i> (Cyprinodontiformes)

“…In addition, many studies have used ribosomal RNA genes because of their highly repetitive nature, ease of manipulation and biological importance in order to elucidate the evolutionary and demographic history of populations (e.g. Sollner-Webb and Mougey 1991, Ghigliotti et al 2008, Torres-Machorro et al 2010). …”

Exploring the diversity of Arctic eelpouts: First cytogenetic data on species of the genus Lycodes (Teleostei, Zoarcidae)

“…A step forward in the knowledge of marine diversity in the Arctic has been made during the fourth International Polar Year (IPY 2007(IPY -2008 that included studies on the taxonomy and geographic distributions of marine fish. Given their recognized value in identifying and describing taxonomic units (Frankham et al, 2004), genomic analyses at the chromosomal level are currently included in programs aimed at monitoring the fish diversity in the Arctic (Christiansen, 2012;Ghigliotti et al, 2005Ghigliotti et al, , 2008, as it has also been done in Antarctica (e.g. di Prisco et al, 1998;Ghigliotti et al, 2010;Pisano et al, 2011;Pisano and Ozouf-Costaz, 2003;Tomaszkiewicz et al, 2011).…”