Cytogenetics of the Brazilian whiptail lizard Cnemidophorus littoralis (Teiidae) from a restinga area (Barra de Maricá) in Southeastern Brazil

Abstract

Chromosomes of Cnemidophorus littoralis, a new species of teiid lizard recently described, were studied. The animals are from a restinga area in Barra de Maricá, RJ. The karyotype presents a diploid number of 2n = 46 chromosomes and a chromosomal sex determination mechanism of the type XX:XY. Nucleolar organizer regions, Ag-NORs, are at the sixth pair of chromosomes; there is variability of size and number of the Ag-stained nucleoli on the 50 interphase nuclei for each specimen analyzed. These nucleoli are related to NOR patterns that also demonstrated variability in size and number. This paper presents the first description of the karyotype of Cnemidophorus littoralis and of a chromosomal sex determination mechanism of the XX:XY type in the genus Cnemidophorus from Southeastern Brazil.Key words: restinga, lizards, karyotype, sex chromosomes. RESUMO Citogenética de Cnemidophorus littoralis (Teiidae) da restinga da Barra de Maricá no Sudeste do BrasilEstudamos os cromossomos de Cnemidophorus littoralis, uma nova espécie de lagarto recentemente descrita, pertencente à família Teiidae. Os animais são oriundos de uma população de restinga na Barra de Maricá, RJ. O cariótipo apresenta número diplóide 2n = 46 cromossomos, com mecanismo cromossômico de determinação do sexo do tipo XX:XY. As regiões organizadoras do nucléolo, Ag-RONs, estão no sexto par de cromossomos. Analisamos 50 núcleos interfásicos corados pela prata para cada exemplar e observamos variação quanto ao número e ao tamanho de nucléolos; estes estão relacionados aos padrões RONs, que também apresentaram variação quanto ao tamanho e ao número. Este trabalho também descreve pela primeira vez a presença de um mecanismo de determinação cromossômica do sexo para o gênero Cnemidophorus do Sudeste do Brasil.Palavras-chave: restinga, lagartos, cariótipo, cromossomos sexuais, espécie endêmica.

Banding patterns and chromosomal evolution in five species of neotropical Teiinae lizards (Squamata: Teiidae)

“…littoralis (Peccinini-Seale et al 2004) is very doubtful. These regions were localized at the telomeres of pair 8, but considering that the size of the chromosomes 4-9 is very similar, specially those from intestinal epithelial cells presented in those articles, we do discard the hypothesis that the Ag-NORs occur at the pair 8 in these two species because of the poor quality of the chromosomal preparations presented by Rocha et al (1997) and Peccinini-Seale et al (2004). Future studies involving NOR location in larger sampling of C. ocellifer are needed to investigate this variation, but it seems that NOR location represents a diagnostic characteristic to study the differentiation of Teiinae.…”

“…Moreover, the absence of heteromorphism in the heterochromatin distribution between the homologous pairs corroborates meiotic data that do not revealed heteromorphic sex chromosomes in this species. On teiids, chromosomal sex determination (XX : XY) was reported for Aspidoscelis tigris; conventionally (Cole et al 1969) and after C-banding (Bull 1978), and in C. littoralis on the basis of conventional staining (Peccinini-Seale et al 2004). …”

“…Nevertheless, these contributions were based only on conventionally stained karyotypes; a method that does not establish homologies essential to properly understand chromosomal evolution and phylogenetic relationships of a group. Banded karyotypes were only described for around 8% of the Teiinae taxa (Bickham 1976;Bull 1978;Schmid and Guttenbach 1988;Porter et al 1991Porter et al , 1994Veronese et al 2003;Peccinini-Seale et al 2004), with some reports controversial (Peccinini-Seale and Almeida 1986; Sites et al 1990;Rocha et al 1997) or not properly illustrated (Rocha et al 1997;Veronese et al 2003).…”

Sex Chromosome Evolution in Lizards: Independent Origins and Rapid Transitions

“…[Gorman and Aitkins, 1968], AMO: Anolis monesis [Gorman and Stamm, 1975], BDU: Bassiana duperreyi [Shine et al, 2002], BTR: Bipes tridactylus [Cole and Gans, 1987], CEN: Claireascincus entrecasteauxii [Hutchinson and Donnellan, 1992], CLE: Calyptommatus leiolepis [Yonenaga-Yassuda et al, 2005], CLI: Cnemidophorus littoralis [Peccinini-Seale et al, 2004], CTI: Cnemidophorus tigris [Cole et al, 1969], DIN: Delma inornata [King, 1990], DNO: Dibamus novaeguineae [Cole and Gans, 1997], GCE: Gonatodes ceciliae [McBee et al, 1987], GGE: Gekko gecko [Solleder and Schmid, 1984], GHO: Gekko hokouensis [Kawai et al, 2009], GPL: Gymnophthalmus pleei [Cole et al, 1990], GPU: Gehyra purpurascens [Moritz, 1984], LBU: Lialis burtonis [Gorman and Gress, 1970], LVI: Lacerta vivipera [Odierna et al, 2001], MAL: Micrablepharus allicolus [Yonenaga-Yassuda and Rodrigues, 1999], PLA: Phyllodactylus lanei [King, 1981], PSI: Podarchis sicula [Odierna et al, 1993], PVI: Pogona vitticeps [Ezaz et al, 2005], PVL: Phrynocephalus vlangalii [Zeng et al, 1997], SCZ: Saproscincus czechurai [Donnellan, 1991], SLA: Scincella lateralis [Wright, 1973], SLU: Sceloporus lundelli [Cole, 1970], SMA: Sceloporus maculosus [Cole, 1971], VAC: Varanus acanthurus [King et al, 1982].…”

Status of Early 19th-Century Names Authored in Parallel by Wied and Schinz for South American Reptiles and Amphibians, with Designations of Three Nomina Protecta

“…The following 25 references meet the criteria quoted above: Adeoye and ogunbanwo, 2007;Cabrera, 2004;Colli et al, 2003aColli et al, , 2003bColli et al, , 2009Dias and Rocha, 2004;Dias et al, 2002;feltrim and lema, 2000;giugliano et al, 2006;Menezes et al, 2000Menezes et al, , 2004aMenezes et al, , 2004bMesquita and Colli, 2003;Peccinini-Seale et al, 2004;Peloso et al, 2008;Reeder et al, 2002;Ribeiro et al, 2007;Rocha et al 1997Rocha et al , 1999Rocha et al , 2005Rocha et al , 2008Rocha et al , 2009Vrcibradic et al, 2002.…”