Karyological analyses of Pseudhymenochirus merlini and Hymenochirus boettgeri provide new insights into the chromosome evolution in the anuran family Pipidae

A karyological study of three typhlopid species with some inferences on chromosome evolution in blindsnakes (Scolecophidia)

“…As previously shown in different taxa by several karyological studies (see e.g. Odierna et al, 2002;Aprea et al, 2013;Mezzasalma et al, 2014Mezzasalma et al, , 2015, adding karyological to phylogenetic data can be useful to detect evolutionary trends and plesiomorphic and apomorphic states, allowing to propose hypotheses on the karyotype diversification in the studied species (see Figs. 3 and 4).…”

“…Madatyphlops arenarius has conserved the primitive snake karyotype of 2n=36 with 16 biarmed macro-and 20 microchromosomes and NORs on a microchromosome pair. The karyotype of X. vermicularis differed in showing a reduced number of microchromosomes (16) and NORs on the long arms of the third macrochromosome pair. The parthenogenetic I. braminus exhibited a triploid karyotype of 3n=42 with seven macro-and seven microtriplets and NORs on a microtriplet.…”

Cytogenetic characterization and B chromosome diversity in direct-developing frogs of the genus Oreobates (Brachycephaloidea, Craugastoridae)

“…B chromosomes are widespread among eukaryotes (Beukeboom 1994, Camacho 2005), and to date have been formally reported in 20 anuran species (Green 2004 and references therein, Lanzone et al 2008, Schmid et al 2010 and references therein, Milani et al 2011, Hernández-Guzmán et al 2011, Suárez et al 2013, Mezzasalma et al 2015). Schmid et al (2010) analyzed with conventional solid staining the chromosomes of 11 specimens of Oreobates discoidalis , collected by J.P. Bogart in 1969 in northwestern Argentina (Aguas Negras, Jujuy).…”

Evolutionary Dynamics of the Repetitive DNA in the Karyotypes of Pipa carvalhoi and Xenopus tropicalis (Anura, Pipidae)

“…The second clade, known as the Xenopus laevis group, encompasses 25 species, with diploid numbers ranging from 4n = 36 to 12n = 108, resulting from a series of independent allopolyploidization events beginning with an ancestral karyotype of 2n = 18 chromosomes (see the list to Zattera et al, 2019). In this case, the primitive 2n = 18 karyotype appears to have been derived from the fusion of chromosomes 9 + 10 in the ancestral 2n = 20 karyotype (Mezzasalma et al, 2015;Session et al, 2016).…”

“…If this hypothesis is true, the diversification of the pipid karyotype would be due primarily to intrachromosomal rearrangements (see Mezzasalma et al, 2015). As the morphology of pairs 1, 2, 3, and 4 of the pipid karyotype is conserved, as it is in Rinophrynus dorsalis (sister-group of the Pipidae), the use of the repetitive DNA as a probe in FISH assays should enable the identification of karyological differences imperceptible by classical chromosome markers.…”