Cytogenetic analyses of five amazon lizard species of the subfamilies Teiinae and Tupinambinae and review of karyotyped diversity the family Teiidae

Abstract

Lizards of the family Teiidae (infraorder Scincomorpha) were formerly known as Macroteiidae. There are 13 species of such lizards in the Amazon, in the genera Ameiva (Meyer, 1795), Cnemidophorus (Wagler, 1830), Crocodilurus (Spix, 1825), Dracaena (Daudin, 1801), Kentropyx (Spix, 1825) and Tupinambis (Daudin, 1802). Cytogenetic studies of this group are restricted to karyotype macrostructure. Here we give a compilation of cytogenetic data of the family Teiidae, including classic and molecular cytogenetic analysis of Ameiva ameiva (Linnaeus, 1758), Cnemidophorus sp.1, Kentropyx calcarata (Spix, 1825), Kentropyx pelviceps (Cope, 1868) and Tupinambis teguixin (Linnaeus, 1758) collected in the state of Amazonas, Brazil. Ameiva ameiva, Kentropyx calcarata and Kentropyx pelviceps have 2n=50 chromosomes classified by a gradual series of acrocentric chromosomes. Cnemidophorus sp.1 has 2n=48 chromosomes with 2 biarmed chromosomes, 24 uniarmed chromosomes and 22 microchromosomes. Tupinambis teguixin has 2n=36 chromosomes, including 12 macrochromosomes and 24 microchromosomes. Constitutive heterochromatin was distributed in the centromeric and terminal regions in most chromosomes. The nucleolus organizer region was simple, varying in its position among the species, as evidenced both by AgNO3 impregnation and by hybridization with 18S rDNA probes. The data reveal a karyotype variation with respect to the diploid number, fundamental number and karyotype formula, which reinforces the importance of increasing chromosomal analyses in the Teiidae.

ZW, XY, and yet ZW: Sex chromosome evolution in snakes even more complicated

“…, Carvalho et al. ), whereas related lacertid lizards with female heterogamety have highly differentiated sex chromosomes (Pokorná et al. ; Rovatsos et al.…”

The Organization of Repetitive DNA in the Genomes of Amazonian Lizard Species in the Family Teiidae

“…1, the 5S rDNA sites are present only on one chromosome pair, which could serve as a protection strategy against transposition events and permutation and could act on dispersion of these sequences [Galetti and Martins, 2004;Martins and Wasko, 2004]. However, this species is in the process of being described, and its phylogenetic relation is still unclear, with special attention being warranted to the total disagreement of cytogenetic data found compared with chromosomal information already described for this teiid species [Carvalho et al, 2015].…”

“…By comparison of the chromosomal location of 5S rDNA with the 18S rDNA (family 45S rDNA) described by Carvalho et al [2015] in the same species (notably, the same individuals were analyzed in these 2 studies), it is clear that these rDNAs have no syntenic position in any species. This feature would prevent chromosomal rearrangements between chromosomes carrying 45S and 5S rDNA sites [Galetti and Martins, 2004;Martins, 2007] and would facilitate the action of different RNA polymerases, because 45S rDNA is transcribed by RNA polymerase I and 5S rDNA is transcribed by RNA polymerase III [Martins, 2007].…”

“…The karyotypes of more than 70% of the Teiidae species have already been described, with most of them having microchromosomes [for review, see Carvalho et al, 2015]. Microchromosomes are universal characteristics in the karyotypes of birds and reptiles and have great value in adaptive evolution [Burt, 2002].…”

“…Mitotic metaphases were processed in Adobe Photoshop CS4 software and were measured using Image J software. Karyotypes were organized in decreasing order following the karyotype formula proposed by Carvalho et al [2015], with A. ameiva , K. calcarata, and K. pelviceps, which are carriers of 2n = 50 chromosomes, being classified by a gradual series of acrocentric chromosomes; Cnemidophorus sp. 1 with 2n = 48 chromosomes of 2 bi-armed chromosomes, 24 uni-armed chromosomes, and 22 microchromosomes; and T. teguixin with 2n = 36 chromosomes, with 12 macro-and 24 microchromosome.…”