Cytogenetics of Brazilian monkeys

American Journal of Primatology, 2005

Genetica, 2006

Potamotrygonidae is the representative family of South American freshwater elasmobranchs. It is a monophyletic group containing 20 species grouped into three genera. Three species belonging to two genera of this family were collected from the middle Negro River, Amazonas, Brazil, and studied cytogenetically: Paratrygon aiereba, Potamotrygon motoro and Potamotrygon orbignyi. Paratrygon aiereba presented 2n=90 chromosomes and 4M+2SM+10ST+74A. Both species of Potamotrygon presented 2n=66 chromosomes and differed in their chromosomal formulas: P. motoro had 18M+12SM+10ST+26A and P. orbignyi had 22M+10SM+8ST+26A. No sex heteromorphism was detected. The Fundamental Number (FN) was 106 for the three species. A system of multiple NORs was found in the three species, but with interspecific differences in terms of location and position of the active Ag-NORs sites. Paratrygon aiereba presented only four sites on the short arms of two chromosomal pairs, both in terminal regions. Potamotrygon motoro presented seven sites, on the long and short arms, all in terminal regions of nonhomologous chromosomes; P. orbignyi presented eight sites on the long arms, all in terminal regions, of non-homologous chromosomes. The constitutive heterochromatin was in pericentromeric regions of all chromosomes, and no significant interspecific difference was found in relation to this marker.

Journal of Human Evolution, 1982

Hypostomus is a group of fish with numerical and structural karyotypic variability. Among them, only six species, three of which belong to the Amazon basin, show a sex chromosome. In this study, we present the karyotype structure of Hypostomus cf. plecostomus from the Teles Pires river basin in the municipality of Alta Floresta, MT. The species has 2n = 68 and the karyotype formula 14m+ 24sm+ 14st+ 16a [fundamental number (FN) = 120] in males and 15m+ ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (2): 6625-6634 24sm+14st+15a (FN = 121) in females and sex chromosomes ZZ/ZW. Argyrophilic nucleolar organizer regions (AgNORs) were identified in two pairs of chromosomes at different positions: short arm of the pair 21and long arm of the pair 27, matching the signals displayed by 18S FISH and indicating multiple NORs. Analysis of band C detected few blocks of constitutive heterochromatin in the pericentromeric regions of most chromosomes and the telomeric regions of some pairs, including the nucleolar pair 21. However, large blocks on the long arm of the nucleolar pair 27 still stood out. GC-rich heterochromatin (CMA 3 ) was visualized only coincidently with nucleolar sites. Mapping of 5S rDNA sites with FISH revealed markings in eight chromosomes, demonstrating synteny between the 18S and 5S sites. The data obtained for H. cf. plecostomus are important for taxonomic studies of this Amazon complex "H. plecostomus group". The occurrence of sex chromosomes in Amazon species of Hypostomus suggests an evolutionary event that is independent of other species in the group.

Chromosoma, 1990

We studied the karyotype of specimens of Callithrix emiliae (Callithricidae, Primates) from Rondonia, Brazil. Comparison with the karyotype of Callithrixjacchus showed that, even though these two species show many karyotypic similarities, they differ by a Robertsonian translocation, a paracentric inversion and large-scale addition of heterochromatin. The C. emiliae species appears to be in an active phase of chromosome evolution by the addition of constitutive heterochromatin. 7

Hereditas, 2004

We describe a new karyotype of Callicebus torquatus using conventional staining, G-banding with Wright Stain, CBG, Ag-NOR staining and fluorescence in situ hybridization (FISH) with human telomere probes and comparative analysis with the previously reported karyotype of C. torquatus torquatus (2n = 20). We studied a female specimen maintained in captivity at the Centro Nacional de Primatas (Para, Brazil). This titi monkey presented 2n = 22, with four large biarmed and six acrocentric autosome pairs; the X chromosome is a medium submetacentric. C-bands were revealed at the centromeric region of all acrocentrics and X chromosome; punctual C-bands also are visualized at the centromeric region in the large biarmed pairs. The NOR site was located at the long arm of pair 4, at the position of a conspicuous secondary constriction. Hybridization signals were detected exclusively at the terminal region of all chromosomes. The karyotype described here has one acrocentric pair more than that found in the literature and also differs by amount and distribution of constitutive heterochromatin. Our data support the notion that the torquatus group may be composed of distinct species, each with its own karyotype.

Caryologia, 1987

The somatic karyotypes of fifteen species of Indian teleostean fishes, namely, Mystus vittatus vittatus (2n = 54; 28m + 22 sm + 2st + 2T) and Rita rita (2n = 54; 14m + 34 sm + 6st) of the family Bagridae, Aspidoparia morar (2n = 48; 8m + 6sm + 34T), Cyprinus carpio communis (2n = 100; 24m + 24sm + 52T), Garra gotyla gotyla (2n = 50; 14m + 26sm + lOT), and Puntius stigma .(2n = 48; 4m + 2sm + 42T) of the family Cyprinidae, Awaous grammepomus (2n = 46; 46T) of the family Gobiidae, Odontamblyopus rubicundus (2n = 46; 4m + 24sm + Sst + lOT) of the family Gobioididae, Macrognathus aculeatum (2n = 48; 8m + 2sm + 38T) and Mastacembelus pancalus (2n = 48; 14m + 12sm + 14st + 8T) of the family Mastacembelidae, Eleutheronema tetradactyla (2n = 48; 48T) of the family Mugilidae, Notopterus notopterus (2n = 42; 42T) of the family Notopteridae, Pisodonophis bora (2n = 38; 18m + 4sm + 4st + 12T) of the family Ophichthidae, Pangasius pangasius (2n = 58; 14m + 20sm + 2st + 22T) of the family Pangasiidae and Tetraodon cutcutia (2n = 42; 16m + 12sm + 4st + lOT) of the family Tetraodontidae are described. The germinal chromosomes in C. carpio communis, P. stigma and A. grammepomus have also been studied. The possible mechanism of karyotypic evolution in these species has been focussed and the possibility of the occurrence of chromosomal polymorphism in some populations of certain species of fish has also been pointed out.

Folia Geobotanica et Phytotaxonomica, 1977

K~ryotypes of twelve species from twenty-four localities in southern Moravia a n d one locality in Slovakia were investigated. Their counts or karyotypic formulae are as follows: Chenopodium foliosum (MoENCH) ASCHERSON: K (2n) = 18 = 16 A m + 2 B am ; Astragalus austriacus J'ACQ.: K (2 n) ~ 16 ~ 8 A m + 8 B s m ; Astragalus exscapus L.: K (2 n) = 16 = 1 0 A m + 4 B s m + + 2 Cst; Astragalus cicer L.: K (2n) = 64; Astragalus onobrychis L.: K (2n) = 64 a n d K (2n) 64 + 1; Vicia dumetorum L.: K (2 n) ~ I4 = 1 0 A m + 4 B s m ; Vicia sylvatica L.: K (2 n) = ~ 1 4~2 A r a + 1 0 B s m + 2Cst; Vicia pisiformi8 L.: ]~(2 n)~ 1 2~S A m + 4 B s m ; V~cia cassubica L.: K (2 n) ~ 12 ~ 4 A m + 6 B s m + 2Cst; Vicia cracca L. (from five localities in s o u t h e r n Moravia): K (2n) = 28 ~ 4 A TM + 12 Bsm + 12 C st and K (2n) = 28 + 1 ~ 5 A m + + 12 B sm + 12 Cat; Vicia cracca L. (from one locality in Slovakia): K (2n)-14 = 2 A m + + 6 B s m + 6Cat; Vicia tenulfolia ROTH: K (2 n) = 24 = 4 A m + 16B s m + 4Cst; Serratula 9 m# I,, 2 4t.. %.

Journal of Arachnology, 2007

Pholcidae (Haplogynae) encompasses 967 described species, of which only 14 have been cytogenetic analyzed. Several chromosomal features have already been described including presence of meta-and sub-metacentric chromosomes and sex determination chromosome system (SDCS) of the X, X 1 X 2 Y, and X 1 X 2 types, which contrast with the telo-and acrocentric chromosomes and SDCS of the X 1 X 2 type typical of entelegyne spiders. To obtain further cytogenetic information for the family, we examined two pholcid species, Crossopriza lyoni (Blackwall 1867) and Physocyclus globosus (Taczanowski 1874) using both conventional staining and silver staining techniques. Crossopriza lyoni exhibited 2n ϭ 23 ϭ 22 ϩ X in males and 2n ϭ 24 ϭ 22 ϩ XX in females, while P. globosus showed 2n ϭ 15 ϭ 14 ϩ X and 4n ϭ 30 ϭ 28 ϩ 2X, both in male adults, 2n ϭ 16 ϭ 14 ϩ XX in female adults and embryos, and 2n ϭ 15 ϭ 14 ϩ X in male embryos. Both species revealed predominately metacentric and submetacentric chromosomes and a SDCS of the X/XX type. The cytogenetic data obtained in this work and those already recorded for C. lyoni indicate interpopulational and intraspecific numerical chromosome variation, suggesting the presence of chromosomal races or cytotypes in this species. The intraindividual numerical chromosome variation observed in male adult specimens of P. globosus may be explained by the presence of cytoplasmatic bridges between germ cells. The use of the silver staining technique to reveal the nucleolar organizer region (NOR) showed that chromosome pairs 4 and 6 and the X chromosome in C. lyoni are telomeric NOR-bearers, and that the chromosome pair 2 in P. globosus possesses a proximal NOR in the long arm.

Genetica

Anopheles cruzii is the most common species of mosquito in Southeast Brazil and a vector of human and monkey malaria. The banding pattern of the ovarian polytene chromosomes and the frequencies of paracentric inversions of individuals from two populations were studied. A new sequence of bands on the sex chromosome, defined as form C, was disclosed. In both populations where forms A (considered as standard) and C are sympatric no heterozygotes were detected. A sequence of events that could account for the observed changes in the banding sequences of the X chromosome forms was proposed. The frequencies of 22 paracentric inversions were used to assess panmixia and the results indicated the presence of two distinct genetic pools in each population. We consider these results as evidence of another sibling species in the taxon cruzii, characterized by a distinctive form of the X chromosome and provisionally designated Anopheles cruzii species C.