Research Article |
Corresponding author: Natália Dayane Moura Carvalho ( nathydayane@gmail.com ) Academic editor: Larissa Kupriyanova
© 2015 Natália Dayane Moura Carvalho, Federico José Arias, Francijara Araújo da Silva, Carlos Henrique Schneider, Maria Claudia Gross.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Carvalho NDM, Arias FJ, da Silva FA, Schneider CH, Gross MC (2015) Cytogenetic analyses of five amazon lizard species of the subfamilies Teiinae and Tupinambinae and review of karyotyped diversity the family Teiidae. Comparative Cytogenetics 9(4): 625-644. https://doi.org/10.3897/CompCytogen.v9i4.5371
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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, K. calcarata and K. 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.
Macroteiidae , Chromosome, Heterochromatin, Differential staining, rDNA-FISH
The family Teiidae is composed of lizards formerly known as macroteiids that are restricted to the New World (
Most chromosome data for teiid lizards refer only to the determination of diploid numbers and karyotype formulae (
The family Teiidae can be divided into two chromosomal groups: the Dracaena group (currently the subfamily Tupinambinae), which has a karyotype with 34–38 chromosomes and a clear distinction of macrochromosomes (M) from microchromosomes (mi), and the Ameiva group (currently the subfamily Teiinae), which has a diploid number ranging from 46–56 chromosomes, with no distinction between macrochromosomes and microchromosomes (
We did a cytogenetic study of five species in the family Teiidae (Ameiva ameiva (Linnaeus, 1758), Cnemidophorus sp.1, Kentropyx calcarata (Spix, 1825), Kentropyx pelviceps (Cope, 1868) and Tupinambis teguixin (Linnaeus, 1758)) using classical as well as molecular cytogenetic markers (conventional staining, heterochromatin patterns, NOR locations and chromosomal physical mapping of 18S rDNA sequences). Karyotype organization in the family is discussed.
Thirty-three specimens belonging to the subfamilies Teiinae and Tupinambinae were collected in the state of Amazonas, Brazil, in the following localities: the riverside forests of the Jatapu river, the city of São Sebastião do Uatumã (0°50' - 01°55'S; 58°50' - 60°10'W), the Darahá and Ayuanã rivers, both in the city of Santa Isabel do Rio Negro (0°24'24"N; 65°1'1"W), the city of Manaus (3°07'13.03"S; 60°01'440"W) and the Purus riverside in the city of Tapauá (5°42'115"S; 63°13'684"W). All of the collections were conducted with permission from the Brazilian Environmental Protection Agency (ICMBio/SISBIO 41825-1). The collection sites are located in public lands (Table
Satellite image of the Amazon basin showing the three different geographical areas; 1 = São Sebastião do Uatumã; 2 = Santa Isabel do Rio Negro; 3 = Tapauá; 4 = Manaus.
Species of the Teiinae and Tupinambinae subfamilies: collection sites, number and the analyzed animals and voucher specimens (lots) are listed. AM: Amazonas.
Subfamily | Species | Collection sites | Number and sex the analyzed animals | Voucher specimens (lots) |
---|---|---|---|---|
Ameiva ameiva | São Sebastião do Uatumã, AM Santa Isabel do Rio Negro, AM Tapauá, AM | 11 (four males; three females; four without sex identification) |
INPA H33213 | |
Cnemidophorus sp.1 | Manaus, AM | 13 (five males; eight females) | INPA H35018 | |
Teiinae | Kentropyx calcarata | São Sebastião do Uatumã, AM | 4 (three males; one females) | INPA H31712 |
Kentropyx pelviceps | Tapauá, AM | 3 (three females) | INPA H34841 | |
Tupinambinae | Tupinambis teguixin | São Sebastião do Uatumã, AM Tapauá, AM | 3 (two females; one without sex identification) | INPA H34791 |
Cellular suspensions were obtained from the bone marrow was removed soon after the euthanasia of animals in the field using an in vitro colchicine treatment (
Genomic DNA was extracted from muscle tissue using a phenol-chloroform protocol (
The PCR product of the 18S rDNA was labeled with digoxigenin-11-dUTP (Dig- Nick Translation mix; Roche), by nick translation according to the manufacturer’s instructions. The antibody anti-digoxigenin rhodamine (Roche) was used for probing the signal. Homologue (DNA probes from the same species) and heterologue (probes of one species hybridized to the chromosome of another) hybridizations were made under stringency conditions of 77% (2.5 ng/µL of 18S rDNA, 50% formamide, 10% dextran sulfate, and 2× SSC at 37 °C for 18 h) (
The diploid number for all specimens of Ameiva ameiva, Kentropyx calcarata and Kentropyx pelviceps was 50 chromosomes, and the karyotypic formula was classified by a gradual series of acrocentric chromosomes (Fig.
Karyotypes of species belonging to Teiinae: a, e, i, m in conventional Giemsa staining b, f, j, n Regions of heterochromatin evidenced by C-band technique c, g, k, o highlight the nucleolar pair impregnated with AgNO3d, h, l, p highlighted in the chromosome pair bearing the site of 18S rDNA (red) and chromosomes were counterstained with DAPI. m = Macrochromossome, mi = microchromossome. Scale bar = 10 µm.
Karyotype of Tupinambis teguixin: a in conventional Giemsa staining b Regions of heterochromatin evidenced by C-band technique c highlight the nucleolar pair impregnated with AgNO3d highlight the chromosome pair bearing the site of 18S rDNA (red) and chromosomes were counterstained with DAPI. m = Macrochromossome, mi = microchromossome. Scale = 10 µm.
Constitutive heterochromatin was observed in the centromeric and terminal regions in most chromosomes of Ameiva ameiva, Cnemidophorus sp.1, Kentropyx calcarata and Kentropyx pelviceps (Figs
The NORs were located in the terminal region of the long arms of pair 7 in Ameiva ameiva (Fig.
Since the 1970s, cytogenetic analysis of the family Teiidae has shown that individuals could be categorized into two groups: the Ameiva group, with diploid number varying from 30–56 chromosomes, with no distinction between macrochromosomes and microchromosomes, and the Dracaena group, with a karyotype varying from 34–38 chromosomes, with a clear distinction between macrochromosomes and microchromosomes (
Most karyotype data comes from species of the subfamily Teiinae, with descriptions of diploid numbers for 63 species. The karyotypes reveal a diploid number varying from 2n=30 in Ameiva auberi (Cocteau, 1838) to 2n=54 in Teius oculatus (D’orbigny & Bibron, 1837) and Teius teyou (Daudin, 1802), besides the presence of sex chromosomes of XX/XY in Aspidocelis tigris tigris (Baird & Girard, 1852) and Ameivula littoralis (Rocha, Bamberg Araújo, Vrcibradic, 2000). Some Aspidoscelis species show triploid numbers such as Aspidoscelis tessalatus (Say, 1823) with 69 chromosomes. Interspecific hybridization has been observed in some species of the genus Aspidoscelis, which were previously placed within the genus Cnemidophorus (
Basic cytogenetic data compiled from the literature for the Teiidae family. Diploid number (2n), karyotypic formula (KF), fundamental number (FN). Three descriptions of karyotypic formulas: (a) number of biarmed chromosomes, number of uniarmed chromosomes and number of microchromosomes; (b) chromosomes that show a gradual series of acrocentric chromosomes; (c) macrochromosome chromosomes (M) and microchromosomes (mi). For data not included in the literature, “-” is indicated.
Subfamily | Genus | Species (sensu [2]) | Species (initial description) | 2n | Type of KF and description | FN | Reference |
---|---|---|---|---|---|---|---|
Callopistinae | Callopistes | Callopistes flavipunctatus | Callopistes flavipunctatus | 2n=38 | c (12M+26m) | 50 | 2 |
Callopistes maculatus | Callopistes maculatus | 2n=38 | c (12M+26m) | 26, 50 | 2, 8 | ||
Teiinae | Ameiva | Ameiva ameiva | Ameiva ameiva | 2n=50 | a (0: 26: 24) b (gradual series of acrocentric chromosomes) |
50 | 2, 18 |
Tupinambinae | Ameiva auberi | Ameiva auberi | 2n=30 | a (8: 10:12) | 38 | 11 | |
Ameiva chrysolaema | Ameiva chrysolaema | 2n=50 | a (0: 22: 28), (6: 20: 24) | 50, 56 | 2 | ||
Ameiva dorsalis | Ameiva dorsalis | 2n=50 | a (4: 22: 24) | 54 | 2 | ||
Ameiva exsul | Ameiva exsul | 2n=50 | a (0: 26: 24) | 50 | 2 | ||
Ameiva maynardi | Ameiva maynardi | 2n=50 | a (4: 22: 24) | 54 | 2 | ||
Ameivula |
Ameivula
nativo
Ameivula litorralis Ameivula ocellifera |
Cnemidophorus
nativo
Cnemidophorus littoralis Cnemidophorus ocellifera |
2n=50 2n=46 (XX/XY) 2n=50 |
a (5: 19: 24) a (5: 19: 22) b(gradual series of acrocentric chromosomes) |
53 51 - |
14 9 18 |
|
Aspidoscelis | Aspidoscelis angusticeps | Cnemidophorus angusticeps | 2n=44, 46 | a (6: 20: 18), a (2: 24: 20) | 50, 48 | 3, 16 | |
Aspidoscelis burti | Cnemidophorus burti | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis calidipes | Cnemidophorus calidipes | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis ceralbensis | Cnemidophorus ceralbensis | 2n=52 | - | - | 4 | ||
Aspidoscelis communis | Cnemidophorus communis | 2n=46 | a (2: 24:20) | 48 | 3 | ||
Aspidoscelis costatus | Cnemidophorus costatus | 2n=46 | a (2: 24:20) | 48 | 3 | ||
Aspidoscelis cozumelae | Cnemidophorus cozumelae | 2n=49, 50 | a (0: 28: 21), a (11: 19: 20) | 49, 61 | 3, 16 | ||
Aspidoscelis deppei | Cnemidophorus deppei | 2n=50, 52 | a (0: 26: 24), a (0: 28: 24) | 50, 52 | 3, 16 | ||
Aspidoscelis exsanguis | Cnemidophorus exsanguis | 3n=69* | - | - | 3, 10 | ||
Aspidoscelis flagellicaudas | Cnemidophorus flagellicaudas | 3n=69* | - | - | 3 | ||
Aspidoscelis gularis | Cnemidophorus gularis | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis guttatus | Cnemidophorus guttatus | 2n=52 | a (0: 28: 24) | 52 | 3 | ||
Aspidoscelis hyperythrus | Cnemidophorus hyperythrus | 2n=52 | a (0: 28: 24) | 52 | 3 | ||
Aspidoscelis inoratus | Cnemidophorus inoratus | 2n=46 | a (2: 24: 20) | 48 | 3, 10 | ||
Aspidoscelis laredoensis | Cnemidophorus laredoensis | 2n=46 | a (2: 24: 20) | 48 | 4 | ||
Aspidoscelis lineatissima | Cnemidophorus lineatissima | 2n=52 | a (0: 28: 24) | 52 | 3 | ||
Aspidoscelis marmoratus | Cnemidophorus marmoratus | 2n=46 | a (0: 22: 24) | 46 | 11 | ||
Aspidoscelis maslini | Cnemidophorus maslini | 2n=47 | a (14: 13: 20) | 49 | 3 | ||
Aspidoscelis mexicana | Cnemidophorus mexicana | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis motaguae | Cnemidophorus motaguae | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis neomexicanus | Cnemidophorus neomexicanus | 2n=46 | a (4: 20: 22) | 50 | 3,10 | ||
Aspidoscelis opatae | Cnemidophorus opatae | 3n=69* | - | - | 3 | ||
Aspidoscelis parvisocius | Cnemidophorus parvisocius | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis rodecki | Cnemidophorus rodecki | 2n=50 | - | - | 1 | ||
Aspidoscelis sacki | Cnemidophorus sacki | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis sptemvittatus | Cnemidophorus sptemvittatus | 2n=46 | a (2: 24: 20) | 48 | 3 | ||
Aspidoscelis sexlineatus | Cnemidophorus sexlineatus | 2n=46 | a (2: 24: 20), a (8: 18: 20) | 48, 54 | 3, 5 | ||
Aspidoscelis sonorae | Cnemidophorus sonorae | 2n=46, 3n=69* | a (4: 20: 22) | 48 | 2, 3, 10 | ||
Aspidoscelis tesselatus | Cnemidophorus tesselatus | 2n=46, 3n=69* | a (4: 20: 22) | 50 | 3, 10, 15 | ||
Aspidoscelis tigris tigris | Cnemidophorus tigris tigris | 2n=46(XX/XY) | a (6: 16: 24) | 52 | 2, 10 | ||
Aspidoscelis tigris aethiops | Cnemidophorus tigris aethiops | 2n=46 | a (6: 16: 24) | 52 | 3 | ||
Aspidoscelis t. estebanensis | Cnemidophorus t. estebanensis | 2n=46 | a (6: 16: 24) | 52 | 3 | ||
Aspidoscelis t. gracilis | Cnemidophorus t. gracilis | 2n=46 | a (6: 16: 24) | 52 | 3 | ||
Aspidoscelis t. marmoratus | Cnemidophorus t. marmoratus | 2n=46 | a (6: 16: 24) | 52 | 3 | ||
Aspidoscelis t. maximus | Cnemidophorus t. maximus | 2n=46 | a (6: 16: 24) | 52 | 3 | ||
Aspidoscelis t. septentrionalis | Cnemidophorus t. septentrionalis | 2n=46 | a (6: 16: 24) | 52 | 3 | ||
Aspidoscelis ubiparens | Cnemidophorus uniparens | 3n=69* | - | - | 3, 10 | ||
Aspidoscelis velox | Cnemidophorus velox | 3n=69* | - | - | 3 | ||
Cnemidophorus | Cnemidophorus arenivagus | Cnemidophorus arenivagus | 2n=50 | a (2: 24: 24) | 52 | 9, 13 | |
Cnemidophorus arubensis | Cnemidophorus arubensis | 2n=50 | a (2: 24: 24) | 52 | 9, 13 | ||
Cnemidophorus cryptus | Cnemidophorus cryptus | 2n=50 | - | 52 | 9 | ||
Cnemidophorus gramivagus | Cnemidophorus gramivagus | 2n=50 | - | 52 | 9 | ||
Cnemidophorus lemniscatus | Cnemidophorus lemniscatus | 2n=50 | a (2: 24: 24) | 52 | 2, 3 | ||
Cnemidophorus murinus | Cnemidophorus murinus | 2n=50 | a (2: 24:24) | 52 | 4, 3 | ||
Contomastix | Contomastix lacertoides | Cnemidophorus lacertoides | 2n=50 | a (0: 26: 24) | 52 | 6, 17 | |
Kentropyx | Kentropyx borckiana | Kentropyx borckiana | 2n=50 | a (0: 26: 24) | 50 | 12 | |
Kentropyx calcarata | Kentropyx calcarata | 2n=50 | b(gradual series of acrocentric chromosomes) | 50 | 12, 19 | ||
Kentropyx striata | Kentropyx striata | 2n=50 | a (0: 26: 24) | 50 | 12 | ||
Kentropyx paulensis | Kentropyx paulensis | 2n=50 | b(gradual series of acrocentric chromosomes) | 50 | 18 | ||
Kentropyx pelviceps | Kentropyx pelviceps | 2n=50 | b(gradual series of acrocentric chromosomes) | 50 | 20 | ||
Kentropyx vanzoi | Kentropyx vanzoi | 2n=50 | b(gradual series of acrocentric chromosomes) | 50 | 18 | ||
Teius | Teius oculatus | Teius oculatus | 2n=54 | a (8: 28: 18) | 62 | 17 | |
Teius teyou | Teius teyou | 2n=54 | a (8: 22: 24) | 62 | 2 | ||
Crocodilurus | - | Crocodilurus lacertinus | 2n=34 | c (12M+22m) | 46 | 2 | |
Crocodilurus amazonicus | Crocodilurus amazonicus | 2n=34 | c (12M+22m) | 46 | 19 | ||
Dracaena |
Dracaena
guianensis
|
Dracaena
guianensis
|
2n=38 |
a (10:2:26) | 48 |
2 | |
Tupinambis | - | Tupinambis nigropunctatus | 2n=36, 38 | a (10: 2: 24), c (16M+22m) | 46, 54 | 2, 7 | |
Tupinambis quadrilineatus | Tupinambis quadrilineatus | 2n=38 | c (12M+26m) | - | 19 | ||
Tupinambis teguixin | Tupinambis teguixin | 2n=38, 36 | a (10: 0: 28), (12M+24m) | 48 | 7, 19 | ||
Salvator | Salvator merianae | Tupinambis merianae | 2n=36, 38 | a (10: 0: 26), c (12M+26m) | 48, 50 | 7, 17, 19 |
Ameiva ameiva and Kentropyx calcarata, which belong to Teiinae, have the same diploid number (2n=50 chromosomes). This result corroborates the available data for these species from different localities (
Furthermore, karyotypic formulae composed of biarmed chromosomes, uniarmed chromosomes and microchromosomes has been described for Ameiva ameiva and Kentropyx calcarata and in the other species genera of the subfamily Teiinae (
Currently, the genus Cnemidophorus is divided into four morphological groups: (1) Cnemidophorus lemniscatus including the species Cnemidophorus arenivagus (Markezich, Cole & Dessauer, 1997), Cnemidophorus arubensis (Lidth de Jeude, 1887), Cnemidophorus cryptus (Cole & Dessauer, 1993), Cnemidophorus flavissimus (Ugueto, Harvey & Rivas, 2010), Cnemidophorus gramivagus (Mccrystal & Dixon, 1987), Cnemidophorus lemniscatus espeuti (Boulenger, 1885), Cnemidophorus lemniscatus gaigei (Ruthven, 1924), Cnemidophorus lemniscatus lemniscatus (Linnaeus, 1758), Cnemidophorus lemniscatus splendidus (Markezich, Cole & Dessauer, 1997), Cnemidophorus pseudolemniscatus (Cole & Dessauer, 1993), Cnemidophorus senectus (Ugueto, Harvey & Rivas, 2010) and Cnemidophorus sp. B.; (2) Cnemidophorus nigricolor including the species Cnemidophorus leucopsammus (Ugueto & Harvey, 2010), Cnemidophorus nigricolor (Peters, 1873), Cnemidophorus rostralis (Ugueto & Harvey, 2010) and Cnemidophorus sp. A; (3) Cnemidophorus murinus including the species Cnemidophorus murinus (Laurenti, 1768) and Cnemidophorus ruthveni (Burt, 1935) and (4) Cnemidophorus vanzoi including the species Cnemidophorus vanzoi (Baskin & Williams, 1966) (
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 (
In the family Teiidae, heterochromatic blocks are located in the centromeric and terminal regions of almost all chromosomes. In some chromosomes, heterochromatic blocks are present in the pericentromeric, interstitial and terminal regions (Table
Cytogenetic banding data compiled from the literature for the differential Teiidae family. Nucleolar organizer regions (NORs), constitutive heterochromatin (CH), fluorescent
Subfamily | Species (Current description) |
Species (Initial description) |
Locality | NOR | CH | FISH | Reference |
---|---|---|---|---|---|---|---|
Teiinae | Ameiva ameiva | Ameiva ameiva | GO, RO, MT, TO | Terminal region of the long arms of pair 7 | Centromeric and terminal regions | - | 8 |
Ameiva ameiva | Ameiva ameiva | AM | Terminal region of the long arms of pair 7 | Centromeric and terminal regions | 18S rDNA (pair 7) | Present work | |
Ameiva auberi | Ameiva auberi | - | - | - | 45S rDNA (pair of microchromosomes) | 4 | |
Aspidoscelis gularis | Cnemidophorus gularis | USA | Centromeric region | - | 1 | ||
Aspidoscelis laredoensis | Cnemidophorus laredoensis | USA | - | Centromeric region | - | 1 | |
Aspidoscelis marmoratus | Cnemidophorus marmoratus | - | - | - | 45S rDNA (pair 2) | 4 | |
Aspidoscelis sexlineatus | Cnemidophorus sexlineatus | USA | - | Centromeric region | - | 1 | |
Aspidoscelis tigris | Cnemidophorus tigriss | USA | - | Centromeric region | - | 2 | |
Ameivula
littoralis
Ameivula nativo Ameivula ocellifera |
Cnemidophorus
littoralis
Cnemidophorus nativo Cnemidophorus ocellifera |
RJ ES BA, SE, MG |
Terminal region of the long arms of pair 8 Multiple NORs (not indicated pairs) Terminal region of the long arms of pair 5 |
- - Centromeric and terminal regions |
- - - |
7 5 8 |
|
Cnemidophorus arenivagus | Cnemidophorus arenivagus | - | Terminal region of the long arms of pair 1 |
- | - | 3 | |
Cnemidophorus cryptus | Cnemidophorus cryptus | - | Terminal region of the long arms of pair 1 | - | - | 3 | |
Cnemidophorus gramivagus | Cnemidophorus gramivagus | - | Terminal region of the long arms of pair 1 | - | - | 3 | |
Cnemidophorus lemniscatus | Cnemidophorus lemniscatus | - | Terminal region of the long arms of pair 1 | - | - | 3 | |
Cnemidophorus sp.1 | - | AM | Terminal region of the long arms of pair 1 | Centromeric and terminal regions | 18S rDNA (pair 1) | Present work | |
Contomastix larcetoides | Cnemidophorus larcetoides | RS | - | Centromeric region | - | 6 | |
Kentropryx calcarata | Kentropryx calcarata | BA, TO, MT | Distal region of the long arms of pair 1 | - | - | 8 | |
Kentropryx calcarata | Kentropryx calcarata | AM | Distal region of the long arms of pair 1 | Centromeric and terminal regions | 18S rDNA (pair 1) | Present work | |
Kentropryx paulensis | Kentropryx paulensis | SP | Distal region of the long arms of pair 1 | Centromeric and terminal regions | - | 8 | |
Kentropyx pelviceps | Kentropyx pelviceps | AM | Distal region of the long arms of pair 1 | Centromeric and terminal regions | 18S rDNA (pair 1) | Present work | |
Kentropryx vanzoi | Kentropryx vanzoi | RO | Distal region of the long arms of pair 1 | - | - | 8 | |
Teius oculatus | Teius oculatus | RS | Multiple NORs (not indicated pairs) | - | - | 6 | |
Tupinambinae | Crocodilurus amazonicus | Crocodilurus amazonicus | PA | Distal region of the long arms of pair 2 | Pericentromeric region | - | 9 |
Salvator meriane | Tupinambis merianae | TO, SP, ES | Distal region of the long arms of pair 2 | Pericentromeric region | - | 9 | |
Tupinambis quadrilineatus | Tupinambis quadrilineatus | GO, TO | Distal region of the long arms of the pair 2 | Centromeric, pericentromeric, interstitial, proximal and terminal regions | - | 9 | |
Tupinambis teguixin | Tupinambis teguixin | GO, TO | Distal region of the long arms of pair 2 | - | - | 9 | |
Tupinambis teguixin | Tupinambis teguixin | AM | Distal region of the long arms of pair 2 | Centromeric and terminal regions | 18S rDNA (pair 2) | Present work |
The heterochromatin patterns for Cnemidophorus sp.1, Kentropyx calcarata, Kentropyx pelviceps and Tupinambis teguixin are described for the first time in this study. The heterochromatin distributional pattern is similar among the analyzed species, suggesting a common pattern for species in the family Teiidae. Three species in the subfamily Tupinambinae (Crocodilurus amazonicus (Spix, 1825), Salvator merianae (Duméril & Bibron, 1839) and Tupinambis quadrilineatus (Manzani & Abe, 1997), however, show species-specific heterochromatin patterns, with heterochromatic blocks in the centromeric, pericentromeric, interstitial and proximal regions of most chromosomes (
Although the five species in the family Teiidae analyzed in the present study present a conserved karyotype macrostructure, some chromosomal characteristics differentiate the karyotype of these species. In Cnemidophorus sp.1, Kentropyx calcarata, Kentropyx pelviceps and Tupinambis teguixin, the presence of a secondary constriction localized in the distal region of pairs 1 and 2 was observed. The secondary constriction is absent in Ameiva ameiva.
Secondary constrictions are typically present in a single chromosomal pair and are very common in several lizard species (
In the present study, the localization of the NORs was revealed as an genus marker and this information has already been discussed for some genera in the family Teiidae, such as Kentropyx (Kentropyx calcarata, Kentropyx paulensis (Boettger, 1893) and Kentropyx vanzoi Gallagher & Dixon, 1980), Crocodilurus (Crocodilurus amazonicus), Cnemidophorus (Cnemidophorus arenivagus, Cnemidophorus cryptus, Cnemidophorus gramivagus and Cnemidophorus lemniscatus lemniscatus), Salvator (Salvator merianae) and Tupinambis (Tupinambis quadrilineatus and Tupinambis teguixin). Localization of the NORs is important for characterizing species and evolutionary studies among teiid lizards (
Tupinambis teguixin has a simple NOR, as evidenced by the secondary constriction of the long arm of pair 2. A common characteristic among species the subfamily Tupinambinae is the presence of such a secondary constriction in pair 2 (
Two populations of Ameiva ameiva from the eastern Amazon showed multiple NORs involving pairs 1, 2, 6, 16, 18, 19 and some small chromosomes (
Using 45S ribosomal DNA probes and FISH, it is possible to understand the organization of the NORs and to elucidate questions concerning the chromosomal organization and karyotypic evolution. The FISH technique is a more refined method than silver nitrate impregnation to locate 45S rDNA sequences in mitotic chromosomes (
Our present data and those from the literature show that teiid lizards have karyotype variation with respect to diploid number, fundamental number and karyotype formula. This, reinforces the importance to increase the number of chromosomal analyses in the family Teiidae. Studies are currently underway with the chromosomal physical mapping of repetitive DNA sequences in three species of Amazonian teiids that are essential for the understanding of genome organization and karyotype evolution in this group of lizards.
This work was supported by the Universidade Federal do Amazonas (UFAM), the graduate program of INPA Genética, Conservação e Biologia Evolutiva, Rede BioPHAM (CNPq/FAPEAM grant number: 563348/2010-0); Conselho Nacional de Pesquisa e Desenvolvimento Tecnológico (grant number: 474617/2013-0); FAPEAM (020/2013); CAPES (Pró-Amazônia – grant number 23038.009447/2013-45, 3295/2013). Species were collected with a permit issued by the Chico Mendes Institute for Biodiversity Conservation (ICMBio/SISBIO license number 41825-1). NDMC received funding from the Fundação de Amparo a Pesquisas do Estado do Amazonas. The authors are grateful to Sergio Marques de Souza for revision of the manuscript and Dra. Eliana Feldberg for the epifluorescence microscope. American Manuscript Editors reviewed this paper.