Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Am J Primatol ; 82(9): e23167, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32652664

RESUMEN

Cheracebus is a new genus of New World primate of the family Pitheciidae, subfamily Callicebinae. Until recently, Cheracebus was classified as the torquatus species group of the genus Callicebus. The genus Cheracebus has six species: C. lucifer, C. lugens, C. regulus, C. medemi, C. torquatus, and C. purinus, which are all endemic to the Amazon biome. Before the present study, there had been no conclusive interpretation of the phylogenetic relationships among most of the Cheracebus species. The present study tests the monophyly of the genus and investigates the relationships among the different Cheracebus species, based on DNA sequencing of 16 mitochondrial and nuclear markers. The phylogenetic analyses were based on Maximum Likelihood, Bayesian Inference, and multispecies coalescent approaches. The divergence times and genetic distances between the Cheracebus taxa were also estimated. The analyses confirmed the monophyly of the genus and a well-supported topology, with the following arrangement: ((C. torquatus, C. lugens), (C. lucifer (C. purinus, C. regulus))). A well-differentiated clade was also identified within part of the geographic range of C. lugens, which warrants further investigation to confirm its taxonomic status.


Asunto(s)
Filogenia , Pitheciidae/clasificación , Animales , ADN Mitocondrial/genética , Pitheciidae/genética , Análisis de Secuencia de ADN , Especificidad de la Especie
2.
Primates ; 60(6): 565-573, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31506896

RESUMEN

The genetic variability of New World primates is still poorly documented. We present the first genetic study on two threatened endemic titi monkey species in northern Bolivia (Plecturocebus modestus and Plecturocebus olallae) using six microsatellite markers to investigate genetic structure and variability of 54 individuals from two wild populations. A low level of genetic diversity was found (34 alleles in the total sampled population). Locus 1118 presented the greatest number of alleles. The mean number of alleles per locus in the total population was 5.6 and the average heterozygosity was 0.38 (range 0.12-0.88). The FIS value for the total population using all microsatellite loci shows a statistically significant heterozygote deficit. The inbreeding coefficients (FIS) were positive and significantly different from zero (0.064 for P. olallae and 0.213 for P. modestus). The genetic differentiation between populations (FST) was moderate with a pair-wise FST estimate of 0.14. Population structure analyses assigned the two populations to two differentiated clusters (K = 2). These results suggest that these two species with very close distributional ranges arose from a single population, and that they remain in a process of genetic differentiation and speciation. This study further underlines the urgent need for conservation actions for both endemic primate species.


Asunto(s)
Variación Genética , Pitheciidae/genética , Bolivia , Especies en Peligro de Extinción , Repeticiones de Microsatélite
3.
Mol Phylogenet Evol ; 132: 117-137, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30496844

RESUMEN

The taxonomy of the titi monkeys (Callicebinae) has recently received considerable attention. It is now recognised that this subfamily is composed of three genera with 33 species, seven of them described since 2002. Here, we describe a new species of titi, Plecturocebus, from the municipality of Alta Floresta, Mato Grosso, Brazil. We adopt an integrative taxonomic approach that includes phylogenomic analyses, pelage characters, and locality records. A reduced representation genome-wide approach was employed to assess phylogenetic relationships among species of the eastern Amazonian clade of the Plecturocebus moloch group. Using existing records, we calculated the Extent of Occurrence (EOO) of the new species and estimated future habitat loss for the region based on predictive models. We then evaluated the species' conservation status using the IUCN Red list categories and criteria. The new species presents a unique combination of morphological characters: (1) grey agouti colouration on the crown and dorsal parts; (2) entirely bright red-brown venter; (3) an almost entirely black tail with a pale tip; and (4) light yellow colouration of the hair on the cheeks contrasting with bright red-brown hair on the sides of the face. Our phylogenetic reconstructions based on maximum-likelihood and Bayesian methods revealed well-supported species relationships, with the Alta Floresta taxon as sister to P. moloch + P. vieirai. The species EOO is 10,166,653 ha and we predict a total habitat loss of 86% of its original forest habitat under a "business as usual" scenario in the next 24 years, making the newly discovered titi monkey a Critically Endangered species under the IUCN A3c criterion. We give the new titi monkey a specific epithet based on: (1) clear monophyly of this lineage revealed by robust genomic and mitochondrial data; (2) distinct and diagnosable pelage morphology; and (3) a well-defined geographical distribution with clear separation from other closely related taxa. Urgent conservation measures are needed to safeguard the future of this newly discovered and already critically endangered primate.


Asunto(s)
Pitheciidae/clasificación , Animales , Teorema de Bayes , Brasil , Citocromos b/genética , Ecosistema , Especies en Peligro de Extinción , Genoma , Mitocondrias/genética , Filogenia , Pitheciidae/anatomía & histología , Pitheciidae/genética , Polimorfismo de Nucleótido Simple
4.
Sci Rep ; 7(1): 7737, 2017 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-28798406

RESUMEN

New World primates feature a complex colour vision system. Most species have polymorphic colour vision where males have a dichromatic colour perception and females can be either dichromatic or trichromatic. The adaptive value of high allelic diversity of opsins, a light sensitive protein, found in primates' eyes remains unknown. Studies revealing the allelic diversity are important as they shed light on our understanding of the adaptive value of differences in the colouration of species and their ecologies. Here we investigate the allelic types found in Pitheciidae, an understudied New World primate family, revealing the diversity of medium/long wavelength sensitive opsins both in cryptic and conspicuous species of this primate family. We found five alleles in Cacajao, six in Callicebinae (i.e. Plecturocebus, Cheracebus, and Callicebus), four in Chiropotes, and three in Pithecia, some of them reported for the first time. Both cryptic and conspicuous species in this group presented high allelic diversity.


Asunto(s)
Variación Genética , Pitheciidae/genética , Opsinas de Bastones/genética , Alelos , Animales , Percepción de Color , Visión de Colores , Femenino , Estudios de Asociación Genética , Genotipo , Masculino
5.
Cytogenet Genome Res ; 151(2): 82-88, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28278505

RESUMEN

We studied the chromosomes of Callicebus nigrifrons with conventional and molecular cytogenetic methods. Our chromosome painting analysis in C. nigrifrons together with previous reports allowed us to hypothesize an ancestral Callicebinae karyotype with 2n = 48. The associations of human chromosomes (HSA) 2/22, 7/15, 10/11, and the inverted HSA2/16 would link Callicebus, Cheracebus, and Plecturocebus and would thus be present in the ancestral Callicebinae karyotype. Four fusions (HSA1b/1c, 3c/8b, 13/20, and 14/15/3/21) and 1 fission (HSA2/22) are synapomorphies of Callicebus. The associations HSA3/15 and HSA3/9 are chromosome features linking Callicebus and Cheracebus, whereas the association HSA13/17 would represent a link between Callicebus and the moloch group (Plecturocebus). Only 6 of the 33 recognized titi monkey species have now been painted with human chromosome-specific probes. Further analyses are needed to clarify the phylogenomic relationships in this species-rich group.


Asunto(s)
Pintura Cromosómica/métodos , Pitheciidae/genética , Animales , Evolución Biológica , Cromosomas de los Mamíferos , Evolución Molecular , Femenino , Humanos , Hibridación Fluorescente in Situ , Cariotipo
6.
Primates ; 58(1): 159-167, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27422802

RESUMEN

There have been recent disagreements as to how many taxa of titi monkeys, genus Callicebus, occur in the region between the Purus and Madeira rivers in western Brazilian Amazonia. Three parapatric taxa were proposed for the area: Callicebus caligatus, Callicebus stephennashi, and Callicebus dubius, but the latter has recently been considered a synonym of C. caligatus, even though both form monophyletic groups and are morphologically distinct. We analyzed the geographic variation in the pelage of Callicebus occurring between the Madeira and Purus rivers and concluded that the phenotypes attributed to C. caligatus and C. dubius are not individual morphs, but rather well-marked and geographically restricted varieties. For this reason, we classify Callicebus caligatus as a polytypic species with two subspecies: Callicebus caligatus caligatus and Callicebus caligatus dubius. This classification is corroborated by molecular evidence as well. The morphological and distributional data indicate that Callicebus stephennashi is a hybrid form of C. c. caligatus and C. c. dubius, due to the presence of intermediate characters. Therefore, until more precise locality records are provided and further evidence is presented, we consider Callicebus stephennashi to be a homonym of the two parental forms.


Asunto(s)
Fenotipo , Pigmentación , Pitheciidae/clasificación , Animales , Brasil , Cabello , Pitheciidae/genética , Pitheciidae/fisiología
7.
Mol Phylogenet Evol ; 102: 208-19, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27235549

RESUMEN

The genus Callicebus (Thomas, 1903) is one of the most diverse of Neotropical primate genera and the only extant member of the Callicebinae subfamily. It has a widespread distribution from Colombia to Brazil, Bolivia, Peru and northern Paraguay. Coat colouring and colour pattern vary substantially within the genus, and this has led to the description of numerous species and subspecies, as well as numerous species groups. However, a lack of molecular phylogenetic analyses on the genus means that phylogenetic relationships and biogeographic history of species are poorly understood. Here, we examined phylogenetic relationships and patterns of diversification within the Callicebus cupreus species Group (sensu Kobayashi, 1995) using complete mitochondrial DNA cytochrome b gene sequence. Analyses indicate that the Callicebus cupreus Group underwent recent and extensive diversification. The common ancestor appears to have emerged some 2.3 million years ago (Ma) from a centre of origin in the western Amazon region, followed by diversification of the group between about 1.5 and 1.2Ma. Phylogenetic analyses were able to recover most previously described species (including the recently described Colombian endemic Callicebus caquetensis). However, there are some notable inconsistences between the obtained phylogeny and current taxonomy. Some previously recognized taxa were not separated by our data (e.g., Callicebus caligatus and Callicebus dubius), while currently unrecognized species diversity was uncovered within C. cupreus in the form of two divergent lineages: one of which exhibited greater phylogenetic similarity to species from the C. moloch Group. Based on the present study, we challenge current taxonomic arrangements for the C. cupreus species Group and call for a thorough taxonomic revision within the genus Callicebus.


Asunto(s)
Pitheciidae/clasificación , Animales , Teorema de Bayes , Evolución Biológica , Citocromos b/genética , ADN/química , ADN/aislamiento & purificación , ADN/metabolismo , ADN Mitocondrial/química , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Filogenia , Filogeografía , Pitheciidae/genética , Análisis de Secuencia de ADN , América del Sur
8.
Proc Biol Sci ; 283(1828)2016 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-27053753

RESUMEN

Colour vision is highly variable in New World monkeys (NWMs). Evidence for the adaptive basis of colour vision in this group has largely centred on environmental features such as foraging benefits for differently coloured foods or predator detection, whereas selection on colour vision for sociosexual communication is an alternative hypothesis that has received little attention. The colour vision of uakaris (Cacajao) is of particular interest because these monkeys have the most dramatic red facial skin of any primate, as well as a unique fission/fusion social system and a specialist diet of seeds. Here, we investigate colour vision in a wild population of the bald uakari,C. calvus, by genotyping the X-linked opsin locus. We document the presence of a polymorphic colour vision system with an unprecedented number of functional alleles (six), including a novel allele with a predicted maximum spectral sensitivity of 555 nm. This supports the presence of strong balancing selection on different alleles at this locus. We consider different hypotheses to explain this selection. One possibility is that trichromacy functions in sexual selection, enabling females to choose high-quality males on the basis of red facial coloration. In support of this, there is some evidence that health affects facial coloration in uakaris, as well as a high prevalence of blood-borne parasitism in wild uakari populations. Alternatively, the low proportion of heterozygous female trichromats in the population may indicate selection on different dichromatic phenotypes, which might be related to cryptic food coloration. We have uncovered unexpected diversity in the last major lineage of NWMs to be assayed for colour vision, which will provide an interesting system to dissect adaptation of polymorphic trichromacy.


Asunto(s)
Visión de Colores , Pitheciidae/fisiología , Opsinas de Bastones/genética , Animales , Cara , Femenino , Masculino , Pitheciidae/genética , Análisis de Secuencia de ADN , Piel
9.
Am J Primatol ; 77(1): 66-75, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25224123

RESUMEN

The pitheciines (Chiropotes, Pithecia, and Cacajao) are frugivorous Neotropical primates that specialize on the predation of seeds from unripe fruits, usually cryptic against the foliage. However, little is known about the color vision distribution within this taxon, and even less about the abilities shared by these animals regarding discrimination of chromatic targets. The aim of this study was to evaluate the color vision perception of captive Uta Hick's cuxiús, or bearded sakis (Chiropotes utahickae) through a behavioral paradigm of color visual discrimination, as well as to estimate, by genetic studies, the number and kinds of medium to long wavelength cone photopigment (opsins) encoded by this species. Among 12 cuxiús (7 males and 5 females) studied only 1 female was diagnosed as a trichromat. Results from genotyping were in line with our behavioral data and showed that cuxiús carried one (dichromat) or two (trichromat) medium to long wavelength pigments alleles, demonstrating a color vision polymorphism in C. utahickae similar to the majority of Neotropical Primates.


Asunto(s)
Visión de Colores/genética , Opsinas de los Conos/genética , Pitheciidae/genética , Alelos , Animales , Pruebas de Percepción de Colores , Visión de Colores/fisiología , Femenino , Genotipo , Masculino , Pitheciidae/fisiología , Polimorfismo Genético
10.
Cytogenet Genome Res ; 137(2-4): 259-72, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22699158

RESUMEN

During the last decades, New World monkey (NWM, Platyrrhini, Anthropoideae) comparative cytogenetics has shed light on many fundamental aspects of genome organisation and evolution in this fascinating, but also highly endangered group of neotropical primates. In this review, we first provide an overview about the evolutionary origin of the inferred ancestral NWM karyotype of 2n = 54 chromosomes and about the lineage-specific chromosome rearrangements resulting in the highly divergent karyotypes of extant NWM species, ranging from 2n = 16 in a titi monkey to 2n = 62 in a woolly monkey. Next, we discuss the available data on the chromosome phylogeny of NWM in the context of recent molecular phylogenetic analyses. In the last part, we highlight some recent research on the molecular mechanisms responsible for the large-scale evolutionary genomic changes in platyrrhine monkeys.


Asunto(s)
Cromosomas de los Mamíferos/genética , Evolución Molecular , Platirrinos/clasificación , Platirrinos/genética , Animales , Atelidae/clasificación , Atelidae/genética , Cebidae/clasificación , Cebidae/genética , Pintura Cromosómica , Análisis Citogenético , Cariotipo , Filogenia , Pitheciidae/clasificación , Pitheciidae/genética , Especificidad de la Especie
11.
Cytogenet Genome Res ; 133(1): 1-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21311179

RESUMEN

Callicebus is a complex genus of neotropical primates thought to include 29 or more species. Currently, the genus is divided into 5 species groups: donacophilus, cupreus, moloch, torquatus and personatus. However, the phylogenetic relationships among the species are still poorly understood. This genus is karyotypically diverse and shows extensive variation in diploid number (2n = 16 to 50). To foster a better understanding of the chromosomal diversities and phylogenetic relationships among the species of Callicebus, we performed a chromosome-painting analysis on the Callicebus personatus genome using human probes, and compared the resulting hybridization map to those of previously mapped titi species. We detected 38 hybridization signals per haploid autosomal set of C. personatus. Few ancestral syntenies were conserved without rearrangement, but 4 human associations (HSA20/13, 3c/8b, 1b/1c and 21/3a/15a/14) were demonstrated to be apomorphic traits for C. persona tus. G-banding suggested that these associations are shared with C. nigrifrons and C. coimbrai (personatus group), while C. personatus is linked with C. pallescens (donacophilus group) by 2 synapomorphies: HSA10b/11 (submetacentric) and an inversion of HSA1a.


Asunto(s)
Genoma , Pitheciidae/genética , Animales , Pintura Cromosómica , Cromosomas Humanos , Cromosomas de los Mamíferos , Femenino , Humanos , Cariotipificación
12.
Am J Primatol ; 73(2): 189-96, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20938927

RESUMEN

The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus.


Asunto(s)
Visión de Colores/genética , Opsinas/genética , Pitheciidae/genética , Polimorfismo Genético , Alelos , Secuencia de Aminoácidos , Animales , Evolución Molecular , Femenino , Ligamiento Genético , Masculino , Datos de Secuencia Molecular , Opsinas/clasificación , Opsinas/fisiología , Perú , Pitheciidae/fisiología , Análisis de Secuencia de ADN , Cromosoma X
13.
BMC Evol Biol ; 10: 189, 2010 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-20565908

RESUMEN

BACKGROUND: The New World monkey (Platyrrhini) subfamily Pitheciinae is represented by the genera Pithecia, Chiropotes and Cacajao. In this work we studied the karyotypes of Pithecia irrorata (2n = 48) and Cacajao calvus rubicundus (2n = 45 in males and 2n = 46 in females) by G- and C-banding, NOR staining and chromosome painting using human and Saguinus oedipus whole chromosome probes. The karyotypes of both species were compared with each other and with Chiropotes utahicki (2n = 54) from the literature. RESULTS: Our results show that members of the Pitheciinae have conserved several chromosome forms found in the inferred ancestral Platyrrhini karyotype (associations of human homologous segments 3a/21, 5/7a, 2b/16b, 8a/18, 14/15a and 10a/16a). Further, the monophyly of this subfamily is supported by three chromosomal synapomorphies (2a/10b, an acrocentric 15/14 and an acrocentric human 19 homolog). In addition, each species presents several autapomorphies. From this data set we established a chromosomal phylogeny of Pitheciinae, resulting in a single most parsimonious tree. CONCLUSIONS: In our chromosomal phylogeny, the genus Pithecia occurred in a more basal position close to the inferred ancestor of Platyrrhini, while C. c. rubicundus and C. utahicki are closely related and are linked by exclusive synapomorphies.


Asunto(s)
Pintura Cromosómica , Filogenia , Pitheciidae/genética , Animales , Cromosomas de los Mamíferos , Sondas de ADN , Evolución Molecular , Femenino , Humanos , Cariotipificación , Masculino , Análisis de Secuencia de ADN
14.
Biochem Genet ; 47(3-4): 235-40, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19169859

RESUMEN

The titi monkeys (Callicebus spp.) are a large, diverse genus of platyrrhines, widely distributed in tropical South America. The genetic variability of these monkeys is still relatively poorly known, especially at the population level. In the present study, four heterologous microsatellite markers were used to investigate genetic diversity in 23 individuals from a wild population of red-bellied titis (Callicebus moloch) in eastern Amazonia. An unexpectedly low level of diversity was found. The average number of alleles was 8.75 (range: 5-15), and the average heterozygosity was 0.33 (range: 0.09-0.65). This preliminary information suggests a reduction of the potential for long-term survival of the population and indicates the putative necessity of implementation of a species conservation program.


Asunto(s)
Repeticiones de Microsatélite/genética , Pitheciidae/genética , Alelos , Animales , Brasil , Variación Genética
15.
Am J Primatol ; 70(12): 1181-6, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18767122

RESUMEN

Population densities of yellow-handed titi monkey (Callicebus torquatus) were estimated using transect census methods. Densities were 2.8 individuals/km(2 )in the upper Rio Itaya basin and 2.5 individuals/km(2) in the lower Rio Algodón basin. Group size varied from two to five individuals, with an average of 2.9 individuals per group at the Rio Itaya. Groups were generally composed of two adults, probably the reproductive pair, with progeny from one to three previous birth seasons. Although the Rio Itaya population is phenotypically identical to populations from the rivers Nanay and Tigre, it differs from population on the rivers Napo and Putumayo. This suggests the existence of two disjunct populations of C. torquatus in Peruvian Amazonia whose taxonomic status warrants further examination.


Asunto(s)
Demografía , Fenotipo , Pitheciidae/anatomía & histología , Animales , Femenino , Masculino , Perú , Pitheciidae/genética , Densidad de Población , Especificidad de la Especie
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA