Differential staining and microchromosomal variation in karyotypes of four Brazilian species of Tupinambinae lizards (Squamata: Teiidae)

Abstract

Kayotypes of four neotropical teiid lizard species (Tupinambinae) were herein studied after conventional as well as silver staining and CBG-banding: Crocodilurus amazonicus (2n = 34), Tupinambis teguixin (2n = 36), Tupinambis merianae and Tupinambis quadrilineatus (2n = 38). The karyological data for T. quadrilineatus as well as those obtained using differential staining for all species were unknown until now. The karyotypes of all species presented 12 macrochromosomes identical in morphology, but differed in the number of microchromosomes: 22 in C. amazonicus, 24 in T. teguixin and 26 in T. quadrilineatus and T. merianae. The Ag-NOR located at the secondary constriction at the distal end of pair 2 is shared by all species, contrasting with the variability observed for this character in species of the related Teiinae. CBG-banding revealed a species-specific pattern in T. quadrilineatus with conspicuous interstitial C-blocks at the proximal region of the long arm of pair 4 and the whole heterochromatic short arm of pair 6. The karyological data reported here corroborates the relationship hypothesis obtained for Tupinambis based on molecular characters. T. teguixin presents the putative ancestral karyotype for the genus with 2n = 36 whereas T. merianae and T. quadrilineatus exhibit 2n = 38, due to an additional pair of microchromosomes.

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

“…No sex chromosome system has been documented in the subfamily (Gorman 1970). Tupinambis teguixin has 2n=36 chromosomes (12M+24m) (Table 2) the same number and karyotype formula was found by other authors (Gorman 1970, de Smet et al 1981, Santos et al 2008). Beçak et al (1972) described a diploid number of 38 chromosomes (12M+26m) for Tupinambis teguixin , with an additional pair of microchromosomes.…”

“…Seven species from the subfamily Tupinambinae, have had their karyotypes analyzed, with diploid numbers varying from 2n=34–38 chromosomes, with the presence of both macrochromosomes and microchromosomes (Santos et al 2008, present study). No sex chromosome system has been documented in the subfamily (Gorman 1970).…”

“…1 - Fritts 1969; 2 - Gorman 1970; 3 - Lowe et al 1970; 4 - Robinson 1973; 5 - Bickham et al 1976; 6 - Cole et al 1979; 7 - de Smet et al 1981; 8 - Navarro et al 1981; 9 - Peccinini-Seale and Almeida 1986; 10 - Ward and Cole 1986; 11 - Porter et al 1991; 12 - Cole et al 1995; 13 - Markezich et al 1997; 14 - Rocha et al 1997; 15 - Walker et al 1997; 16 - Manriquen-Moran et al 2000; 17 - Veronese et al 2003; 18 - Santos et al 2007; 19 - Santos et al 2008; 20 - Present work.…”

“…1 - Bickhan et al 1976; 2 - Bull 1978; 3 - Peccinini-Seale and Almeida 1986; 4 - Porter et al 1991; 5 - Rocha et al 1997; 6 - Veronese et al 2003; 7 - Peccinini-Seale et al 2004; 8 - Santos et al 2007; 9 - Santos et al 2008…”

“…Some species of this family have, however, been analyzed in detail with respect to their chromosomal structure and organization, as revealed by differential staining techniques, such as the detection of heterochromatin and nucleolar organizer regions (NORs), as well as chromosomal physical mapping of DNA sequences (Bickham et al 1976, Bull 1978, Peccinini-Seale and Almeida 1986, Porter et al 1991, Rocha et al 1997, Veronese et al 2003, Peccinini-Seale et al 2004, Santos et al 2007, Santos et al 2008). …”