Can molecular data place each neotropical monkey in its own branch?

Four different DNA datasets, representative of all extant neotropical primate genera, were tandemly aligned, comprising some 6,763 base pairs (bp) with 2,086 variable characters and 674 informative sites. Maximum Parsimony, Maximum Likelihood and Neighbor-Joining analyses suggested three monophyletic families (Atelidae, Pitheciidae and Cebidae) that emerged almost at the same time during primate radiation. Combined molecular data showed congruent branching inside the atelid clade, placing Alouatta as the most basal lineage followed by Ateles and a more derived branch including Brachyteles and Lagothrix as sister groups. In the Pitheciidae, Callicebus was the most basal lineage with respect to Pithecia and to the more derived sister groups (Cacajao and Chiropotes). Conjoint analysis strongly supported the monophyly of the Cebidae, grouping Aotus, Cebus and Saimiri with the small callitrichines. Within callitrichines, Cebuella merged with Callithrix, Callimico appeared as a sister group of Callithrix/Cebuella, Leontopitecus as a sister group of the previous clade, and Saguinus was the earliest callitrichine offshoot. Two major points remained to be clarified in platyrrhine phylogeny: (i) the exact branching pattern of Aotus, Cebus, Saimiri and the callitrichines, and (ii), which two of these three families (Atelidae, Pitheciidae and Cebidae) are more closely related to one another.     

Molecular phylogeny of new world primates (Platyrrhini) based on beta2-microglobulin DNA sequences

Neotropical primates, traditionally grouped in the infraorder Platyrrhini, comprise 16 extant genera. Cladistic analyses based on morphological characteristics and molecular data resulted in topologic arrangements depicting disparate phylogenetic relationships, indicating that the evolution of gross morphological characteristics and molecular traits is not necessarily congruent. Here we present a phylogenetic arrangement for all neotropical primate genera obtained from DNA sequence analyses of the beta2-microglobulin gene. Parsimony, distance, and maximum likelihood analyses favored two families, Atelidae and Cebidae, each containing 8 genera. Atelids were resolved into atelines and pitheciines. The well-supported ateline clade branched into alouattine (Alouatta) and ateline (Ateles, Lagothrix, Brachyteles) clades. In turn, within the Ateline clade, Lagothrix and Brachyteles were well-supported sister groups. The pitheciines branched into well-supported callicebine (Callicebus) and pitheciine (Pithecia, Cacajao, Chiropotes) clades. In turn, within the pitheciine clade, Cacajao and Chiropotes were well-supported sister groups. The cebids branched into callitrichine (Saguinus, Leontopithecus, Callimico, Callithrix-Cebuella), cebine (Cebus, Saimiri), and aotine (Aotus) clades. While the callitrichine clade and the groupings of species and genera within this clade were all well supported, the cebine clade received only modest support, and the position of Aotus could not be clearly established. Cladistic analyses favored the proposition of 15 rather than 16 extant genera by including Cebuella pygmaea in the genus Callithrix as the sister group of the Callithrix argentata species group. These analyses also favored the sister grouping of Callimico with Callithrix and then of Leontopithecus with the Callithrix-Callimico clade.     

Chromosome comparison among five species of platyrrhini (Alouatta caraya,Aotus azarae,Callithrix jacchus,Cebus apella,andSaimiri sciureus)

Karyotypes of 82 individuals from five Platyrrhini species (Alouatta caraya, Aotus azarae, Callithrix jacchus, Cebus apella, andSaimiri sciureus) were studied and compared using a G-banding technique. Cytogenetic analysis showed full chromosome or full arm homologies among these geographically neighbouring species. A small number of chromosomal rearrangements (inversions, deletions, and translocations) could be detected among these taxa. These five species are closely related in chromosomal evolution. An interesting correspondance was found betweenCebus apella chromosomes and those of the other four species.Alouatta caraya andCebus apella are the closest species.Callithrix jacchus andAotus azarae would have the most separated karyotypes.     

Bimodal evolution of the killer cell Ig-like receptor (KIR) family in New World primates

The immunoglobulin-like receptor (KIR) gene family in New World primates (Platyrrhini) has been characterized only in the owl monkey (Aotus sp.). To gain a better understanding of the KIR system in Platyrrhini, we analyzed a KIR haplotype in Ateles geoffroyi, and sequenced KIR complementary DNAs (cDNAs) from other three Atelidae species, Ateles hybridus, Ateles belzebuth, and Lagothrix lagotricha. Atelidae expressed a variable set of activating and inhibitory KIRs that diversified independently from their Catarrhini counterparts. They had a unique mechanism to generate activating receptors from inhibitory ones, involving a single nucleotide deletion in exon 7 and a change in the donor splice site of intron 7. The A. geoffroyi haplotype contained at least six gene models including a pseudogene, two coding inhibitory receptors, and three coding activating receptors. The centromeric region was in a tail-to-tail orientation with respect to the telomeric region. The owl monkey KIR haplotype shared this organization, and in phylogenetic trees, the centromeric genes clustered together with those of A. geoffroyi, whereas their telomeric genes clustered independently. KIR cDNAs from the other Atelidae species conformed to this pattern. Signatures of positive selection were found in residues predicted to interact with the major histocompatibility complex. Such signatures, however, primarily explained variability between paralogous genes but not between alleles in a locus. Atelidae, therefore, has expanded the KIR family in a bimodal fashion, where an inverted centromeric region has remained relatively conserved and the telomeric region has diversified by a rapid process of gene duplication and divergence, likely favored by positive selection for ligand binding.     

Interstitial Telomeric Motifs in Squamate Reptiles: When the Exceptions Outnumber the Rule

Telomeres are nucleoprotein complexes protecting the physical ends of linear eukaryotic chromosomes and therefore helping to ensure their stability and integrity. Additionally, telomeric sequences can be localized in non-terminal regions of chromosomes, forming so-called interstitial telomeric sequences (ITSs). ITSs are traditionally considered to be relics of chromosomal rearrangements and thus very informative in the reconstruction of the evolutionary history of karyotype formation. We examined the distribution of the telomeric motifs (TTAGGG)_n using fluorescence in situ hybridization (FISH) in 30 species, representing 17 families of squamate reptiles, and compared them with the collected data from another 38 species from literature. Out of the 68 squamate species analyzed, 35 possess ITSs in pericentromeric regions, centromeric regions and/or within chromosome arms. We conclude that the occurrence of ITSs is rather common in squamates, despite their generally conserved karyotypes, suggesting frequent and independent cryptic chromosomal rearrangements in this vertebrate group.     

Adaptation of the AMRU-1 strain of Plasmodium vivax to Aotus and Saimiri monkeys and to four species of anopheline mosquitoes.

A chloroquine-resistant strain of Plasmodium vivax (AMRU-1) from Papua New Guinea has been adapted to grow in 4 species of Aotus monkeys (Aotus lemurinus griseimembra, Aotus vaciferans, Aotus nancymai, and Aotus azarae boliviensis), hybrid Aotus monkeys, and Saimiri boliviensis monkeys. Whereas it was possible to infect Saimiri monkeys with this parasite by inoculation of parasitized erythrocytes, only 42% of Saimiri monkeys became infected, compared to 92% of Aotus monkeys attempted. Comparative mosquito feedings showed that only A. vociferans, A. l. griseimembra, and Saimiri boliviensis monkeys produced infections in mosquitoes. Oocysts were observed on the guts of the 4 species of mosquitoes used (Anopheles gambiae, Anopheles stephensi, Anopheles freeborni, and Anopheles dirus), but sporozoite transmission was effected only with the intravenous inoculation of sporozoites from An. dirus into an A. l. griseimembra monkey.     

Observations on the Vietnam Palo Alto strain of Plasmodium vivax in two species of Aotus monkeys

Thirty-three splenectomized Aotus lemurinus griseimembra monkeys with no previous experience with malaria were infected with the Vietnam Palo Alto strain of Plasmodium vivax. The median maximum parasite count was 280,000/microl. Nine splenectomized monkeys with previous infection with Plasmodium falciparum had median maximum parasite counts of 120,000/microl. Splenectomized Aotus nancymai monkeys supported infections at a lower level. Transmission via the bites of Anopheles dirus mosquitoes was obtained in a splenectomized A. lemurinus griseimembra, with a prepatent period of 31 days. It is estimated that between 1.5 x 10(8) and 1.6 x 10(9) parasites can be removed from an infected animal for molecular or diagnostic antigenic studies.     

Studies on the North Korean strain of Plasmodium vivax in Aotus monkeys and different anophelines

Twenty-two Aotus monkeys of different karyotypes were infected with the North Korean strain of Plasmodium vivax. Aotus lemurinus griseimembra animals from Colombia produced higher maximum parasitemias and more readily infected mosquitoes than did Aotus monkeys from Bolivia (K-VI) or Peru (K-V and K-X). Comparative feedings indicated that the most susceptible mosquito species was Anopheles stephensi, followed by An. gambiae, An. dirus, An. freeborni, An. quadrimaculatus, An. culicifacies, and An. maculatus.     

Do time, heterochromatin, NORs, or chromosomal rearrangements correlate with distribution of interstitial telomeric repeats in Sigmodon (cotton rats)?

We studied the chromosomal distribution of telomere repeats (TTAGGG)(n) in 8 species of Sigmodon (cotton rats) using chromosome paints fluorescent in situ hybridization (FISH) from Sigmodon hispidus. In 2 species with the proposed primitive karyotype for the genus, telomere repeats were restricted to telomeric sites. But in the other 6 species that include 3 with proposed primitive karyotypes and 3 with highly rearranged karyotypes, telomere repeats were found on both telomeric sites and within interstitial telomeric sites (ITSs). To explain the distribution of ITS in Sigmodon, we gather data from C-bands, silver nitrate staining, G-bands, and chromosomal paint data from previous published studies. We did find some correlation with ITS and heterochromatin, euchromatic chromosomal rearrangements, and nucleolar organizing regions. No one type of chromosomal structure explains all ITS in Sigmodon. Multiple explanations and mechanisms for movement of intragenomic sequences are required to explain ITS in this genus. We rejected the hypothesis that age of a lineage correlates with the presence of ITS using divergence time estimate analyses. This multigene phylogeny places species with ITS (S. arizonae, S. fulviventer, S. hispidus, S. mascotensis, S. ochrognathus, and S. toltecus) in the clade with a species without ITS (S. hirsutus). Lineages with ITS (S. arizonae and S. mascotensis) arose independently from a lineage absent of ITS (S. hirsutus) around 0.67 to 0.83 Ma. The rearranged karyotypes of S. mascotensis and S. arizonae appear to be an independently derived autapomorphic characters, supporting a fast rate of chromosomal changes that vary among species.     

XX/XY sex chromosome system and chromosome markers in the snake eel Ophisurus serpens (Anguilliformes: Ophichtidae)

We report evidence of an XX/XY sex chromosome system in the snake eel Ophisurus serpens (Anguilliformes: Ophichthidae). We characterized the male and female karyotypes by C-, replication- and HaeIII-bandings. The 45S and 5S ribosomal gene families were located using dual fluorescence in situ hybridization, which showed that the 5S rDNA sites were present on the X chromosome, beside an autosome pair. FISH with a telomeric peptide nucleic acid probe enabled recognition of Interstitial Telomeric Sequences (ITSs), likely remnants of chromosomal rearrangements, in five chromosome pairs, including the rDNA-bearing ones. Possible mechanisms of the origin of sex chromosomes in this species are discussed, considering the presence of a sex-linked marker and ITSs.     

Nutritional and Health Status of Woolly Monkeys

Woolly monkeys (Lagothrix lagotricha and L. flavicauda) are threatened species in the wild and in captivity. Numerous zoological institutions have historically kept Lagothrix lagotricha spp., but only a few of them have succeeded in breeding populations. Therefore the majority of institutions that formerly kept Lagothrix lagotricha are no longer able or willing to do so. Captive populations of the species have frequent health problems, most significantly hypertension and related disorders. Researchers have conducted free-ranging dietary and behavior studies with respect to woolly monkeys, but have established no concrete link between diet or nutrients and captive health problems. The available literature we discuss indicates that researchers need to examine the link further. In addition, it is critical to the survival of the primates to be able to keep breeding populations in captivity owing to increasing natural pressures such as deforestation and hunting. Therefore, better understanding of the captive and free-ranging behavior and health parameters of the species is vital to ensure their survival and to maintain forest health and diversity. Researchers need to conduct large-scale research studies comparing the health and complete diet of individuals in the wild and captivity to resolve health problems facing the species in captivity.     

Molecular cytotaxonomy of New World monkeys (Platyrrhini) - comparative analysis of five species by multi-color chromosome painting gives evidence for a classification of Callimico goeldii within the family of Callitrichidae

Chromosome rearrangements are considered as "rare genomic changes" and can provide useful markers and even landmarks for reconstructing phylogenies complementary to DNA sequence data and bio-morphological comparisons. Here, we applied multi-directional chromosome painting to reconstruct the chromosome phylogeny and evolutionary relationships among the New World monkey (Platyrrhini) species Callithrix argentata, Cebuella pygmaea, Saguinus oedipus, Callithrix jacchus and Callimico goeldii. The results clarified several aspects of New Wold monkey phylogeny. In particular the phylogenetic position of C. goeldii was elucidated, which has been controversially discussed and variously classified in the family Callitrichidae, in the family Cebidae or in its own family Callimiconidae. Comparative genome maps were established by multi-color fluorescence in situ hybridization (FISH) with human, S. oedipus and Lagothrix lagothricha chromosome- specific DNA probes. From these data we reconstructed the putative ancestral karyotype of all Callitrichidae. Various derived chromosomal syntenies are shared by all five species and cytogenetically define Callitrichidae - including Callimico goeldii -- as a distinctive group within the Platyrrhini. C. pygmaea and C. argentata share identical chromosomal syntenies from which S. oedipus and C. jacchus differ by single independent translocations. A common derived chromosomal change links Callimico with the marmosets to the exclusion of the tamarins, however, it has further diverged from an ancestral marmoset karyotype by at least four apomorphic rearrangements. Saimiri sciureus, representing the Cebinae, exclusively shares a derived syntenic association with all Callithrichidae, defining the genus Saimiri as a sister group.     

Analysis of the heterochromatin of <Emphasis Type="Italic">Cebus</Emphasis> (Primates,Platyrrhini) by micro-FISH and banding pattern comparisons

The karyotype of the neotropical primate genus Cebus (Platyrrhini: Cebidae), considered the most ancestral one, shows the greatest amount of heterochromatin described among Platyrrhini genera. Banding techniques and restriction enzyme digestion have previously revealed great variability of quantity and composition of heterochromatin in this genus. In this context, we use fluorescence in situ hybridization (FISH) to analyse this genomic region and discuss its possible role in the diversification of Cebus. We used a heterochromatin probe for chromosome 11 of Cebus libidinosus (11qHe+ CLI probe), obtained by chromosome microdissection. Twenty-six specimens belonging to the families Atelidae, Cebidae, Callitrichidae and Pithecidae (Platyrrhini) were studied. Fourteen out of 26 specimens were Cebus (Cebidae) individuals of C. libidinosus, C. xanthosternos, C. apella, C. nigritus, C. albifrons, C. kaapori and C. olivaceus. In Cebus specimens, we found 6 to 22 positive signals located in interstitial and telomeric positions along the different species. No hybridization signal was observed among the remaining Ceboidea species, thus reinforcing the idea of a Cebus-specific heterochromatin composed of a complex system of repetitive sequences.     

Cytogenetics of Brazilian monkeys

Karyotypic studies were carried out on some species belonging to the family Cebidae. The chromosome complements have been studied in blood cultures in vitro in the following species: Alouatta fusca clamitans (2n = 50); Aotes trivirgatus (2n = 52); Cebus albifrons (2n = 52); Cebus sp. (2n = 54); Ateles paniscus paniscus (2n = 34); Lagothrix lagotricha (2n = 62). Comparison between the present results and the karyotypes of the Cebidae described in the literature reveal intraspecific and interspecific variability in number and structure of the chromosomes.     

Constitutive heterochromatin polymorphism in Lagothrix lagothricha cana,Cebus apella,and Cebus capucinus

We describe the C-bands in the karyotypes of Lagothrix lagothricha cana, Cebus apella and Cebus capucinus. The C-banding patterns show both a high degree of polymorphism as well as the presence of terminal and interstitial C-bands. Varying amounts of heterochromatin result in dimorphism of some chromosome pairs. The high incidence of chromosome rearrangements found in the Cebidae may be due to the presence of terminal and interstitial C-bands.     

Platyrrhine juvenile mortality in captivity and in the wild

I reviewed literature on juvenile mortality in the Platyrrhini in order to evaluate reproductive success in captive breeding. Juvenile mortality includes abortion, premature mortality, stillbirth and death of the unweaned young. The highest losses occur in the Callitrichidae (31% through 3 months of age; 86% through 6 months of age) and in Lagothrixspp. (around 50% through 1 month of age) among the Cebidae. High abortion rates occur in Saguinusand Aotus.High stillbirth incidences are reported for the Callitrichidae (Callithrixand Saguinus)and for the Cebidae (Saimiriand Aotus).Although most mortality occurs in the first week for most species, a considerable proportion of deaths occurs in the period from week 1 until weaning. Important causes of death are trauma and aberrant parental behavior. Prematurity plays an important role in perinatal death among the Callitrichidae. Dystocia is a major cause of stillbirth in Saimiri. Congenital malformations occur in Callithrix, Saguinus, Leontopithecus,and Saimiri.Infectious diseases play a secondary role in mortality, particularly during the first period of life. A higher mortality risk is present if the infant is male, if the litter size is different from two (Callitrichidae), if the mother is primiparous, captive born, or inexperienced, or if the group is small (Callitrichidae) or unstable (Cebidae).     

Endings in the middle: current knowledge of interstitial telomeric sequences

Interstitial telomeric sequences (ITSs) consist of tandem repeats of the canonical telomeric repeat and are common in mammals. They are localized at intrachromosomal sites, including those repeats located close to the centromeres and those found at interstitial sites, i.e., between the centromeres and the telomeres. ITSs might originate from ancestral intrachromosomal rearrangements (inversions and fusions), from differential crossing-over or from the repair of double-strand break during evolution. Three classes of ITSs have been described in the human genome, namely, short ITSs, long subtelomeric ITSs and fusion ITSs. The fourth class of ITSs, pericentromeric ITSs, has been found in other species. The function of ITSs can be inferred from the association of heritable diseases with ITS polymorphic variants, both in copy number and sequence. This is one of the most attractive aspects of ITS studies because it leads to new and useful markers for genetic linkage studies, forensic applications, and detection of genetic instability in tumors. Some ITSs also might be hotspots of chromosome breakage, rearrangement and amplification sites, based on the type of clastogens and the nature of ITSs. This study will contribute new knowledge with respect to ITSs' biology and mechanism, prevalence of diseases, risk evaluation and prevention of related diseases, thus facilitates the design of early detection markers for diseases caused by genomic instability.     

Chromosomal localization of the telomeric (TTAGGG)n sequence in eight species of New World Primates (Neotropical Primates, Platyrrhini)

Chromosomal localization of the telomeric sequence (TTAGGG)(n) in eight New World Primates (Platyrrhini) (Alouatta caraya, Alouatta palliata, Alouatta guariba clamitans, Aotus azarae, Ateles chamek, Cebus nigritus, Cebus paraguayanus, and Saimiri boliviensis) using Fluorescence In Situ Hybridization (FISH) with a peptide nucleic acid (PNA) pantelomeric probe and their possible relationship with the C-banding pattern were analyzed. FISH showed telomeric signals only at the terminal regions of chromosomes from all the species analyzed. Although all of them showed centromeric C+ bands and different size and location of extracentromeric C+ bands, none, except Aotus azarae exhibited (peri)centromeric interstitial telomere-like sequences (ITS). The presence of ITS in Aotus azarae was limited to one pair of submetacentric chromosomes and very likely represents telomeric sequences remaining after a fusion event of ancestral chromosomes during karyotype evolution. Therefore, our data indicate that the distribution of heterochromatin blocks do not correlate with the presence of ITS. However, we cannot rule out the possibility that simple ITS arrays with a few copies of the (TTAGGG)(n) sequence, not detectable by conventional FISH, might play a role in the karyotypic evolution of Ceboidea. Further FISH and molecular studies will be needed to confirm this hypothesis.     

Comparative and functional myology of the prehensile tail in new world monkeys

The caudal myology of prehensile-tailed monkeys (Cebus apella, Alouatta palliata, Alouatta seniculus, Lagothrix lagotricha, and Ateles paniscus) and nonprehensile-tailed primates (Eulemur fulvus, Aotus trivirgatus, Callithrix jacchus, Pithecia pithecia, Saimiri sciureus, Macaca fascicularis, and Cercopithecus aethiops) was examined and compared in order to identify muscular differences that correlate with osteological features diagnostic of tail prehensility. In addition, electrophysiological stimulation was carried out on different segments of the intertransversarii caudae muscle of an adult spider monkey (Ateles geoffroyi) to assess their action on the prehensile tail. Several important muscular differences characterize the prehensile tail of New World monkeys compared to the nonprehensile tail of other primates. In atelines and Cebus, the mass of extensor caudae lateralis and flexor caudae longus muscles is more uniform along the tail, and their long tendons cross a small number of vertebrae before insertion. Also, prehensile-tailed monkeys, especially atelines, are characterized by well-developed flexor and intertransversarii caudae muscles compared to nonprehensile-tailed primates. Finally, Ateles possesses a bulkier abductor caudae medialis and a more cranial origin for the first segment of intertransversarii caudae than do other prehensile-tailed platyrrhines. These myological differences between nonprehensile-tailed and prehensile-tailed primates, and among prehensile-tailed monkeys, agree with published osteological and behavioral data. Caudal myological similarities and differences found in Cebus and atelines, combined with tail-use data from the literature, support the hypothesis that prehensile tails evolved in parallel in Cebus and atelines. © 1995 Wiley-Liss, Inc.     

The place of Callimico goeldii in the Callitrichine phylogenetic tree: evidence from von Willebrand factor gene intron II sequences

Sequences of a 0.9-kb DNA segment spanning intron 11 of the von Willebrand Factor gene (vWF) were determined for 21 individuals of 19 primate species. The results of maximum parsimony and maximum likelihood analyses of these vWF sequences are congruent with previous molecular findings from other nonlinked nuclear genomic loci which divide the platyrrhine superfamily Ceboidea into three monophyletic families: Cebidae, Atelidae, and Pitheciidae. The vWF results strongly support the taxon Callitrichinae as a monophyletic subfamily within Cebidae. The four extant callitrichine genera constitute tribe Callitrichini, and the basal branchings within this tribe first separate out Saguinus (tamarins), next Leontopithecus (lion tamarins), and last the sister genera Callimico (Goeldi's monkeys) and Callithrix (marmosets). Callithrix divides into three subclades, with pygmy marmosets (C. pygmaea) as sister of the C. argentata species group and with the C. jacchus species group as their sister. Fossil and DNA evidence place the emergence of the callitrichine clade in the basal cebid radiation at about 20 Ma (million years ago) and the three basal branchings in the callitrichin radiation at about 13 to 11 Ma. In turn, the branchings separating the three subclades of Callithrix are placed at about 5 to 4 Ma.