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PubMed1993

Comparative high-resolution mapping of human and primate chromosomes by fluorescence in situ hybridization.

A molecular cytogenetic approach that facilitates high-resolution comparative mapping of defined human genes in different primate species is presented. Fluorescence in situ hybridization and digital imaging microscopy were used to visualize human DNA probes on simultaneously banded or "painted" metaphase chromosomes of great apes (Pan troglodytes, Gorilla gorilla, Pongo pygmaeus), hylobatids (Hylobates lar and Hylobates syndactylus), and Old World monkeys (Macaca fuscata and Cercopithecus aethiops). Using a series of DNA probes, chromosomal rearrangements in the karyotypes of primates were readily detected at the molecular cytogenetic level. This approach should contribute considerably to the understanding of primate phylogeny and evolution.

Animals↗
PubMed1997

Social pressures have selected for an extended juvenile period in primates.

Primates are highly social animals. As such, they utilize a large repertoire of social skills to manage their complex and dynamic social environments. In order to acquire complex social skills, primates require an extended learning period. Here 1 perform a comparative analysis using independent contrasts to show that social pressures have favored an extension in the proportion of time primates spend as juveniles.

Aging↗
PubMedDate not supplied

Variations in molar enamel thickness among primates.

Because of its hardness, resistance to abrasion and its influence on crown morphology, molar enamel thickness is an important factor in adaptation of the dentition to the diet. Enamel thickness has also been discussed extensively in relation to the phylogenetic relationships among the hominoids. The aims of this study were: (1) to analyse enamel thickness/tooth size relationships among primates as a whole, and (2) to evaluate variations in enamel thickness among hominoids against the background of the other primates. We employed measures of tooth size, and of enamel thickness and quantity based on measurements of areas in longitudinal sections of 125 molars of 39 species. Among primates, there were two grades of enamel thickness, prosimians having thinner enamel for a given tooth size or body weight than anthropoids. The scaling of enamel thickness with tooth size and body weight tended to show positive allometry among anthropoids. Comparison of hominoid enamel thicknesses with that in anthropoids led to the conclusion that Hylobates has enamel of average thickness, Homo has thick enamel and Gorilla has thin enamel, while Pan and Pongo had average or thin enamel, depending on tooth type. These results may be relevant to considerations of hominoid evolution.

Analysis of Variance↗
PubMed1999

The conditions for tool use in primates: implications for the evolution of material culture.

In order to identify the conditions that favored the flourishing of primate tool use into hominid technology, we examine inter- and intraspecific variation in manufacture and use of tools in extant nonhuman primates, and develop a model to account for their distribution. We focus on tools used in acquiring food, usually by extraction. Any model for the evolution of the use of feeding tools must explain why tool use is found in only a small subset of primate species, why many of these species use tools much more readily in captivity, why routine reliance on feeding tools is found in only two species of ape, and why there is strong geographic variation within these two species. Because ecological factors alone cannot explain the distribution of tool use in the wild, we develop a model that focuses on social and cognitive factors affecting the invention and transmission of tool-using skills. The model posits that tool use in the wild depends on suitable ecological niches (especially extractive foraging) and the manipulative skills that go with them, a measure of intelligence that enables rapid acquisition of complex skills (through both invention and, more importantly, observational learning), and social tolerance in a gregarious setting (which facilitates both invention and transmission). The manipulative skills component explains the distribution across species of the use of feeding tools, intelligence explains why in the wild only apes are known to make and use feeding tools routinely, and social tolerance explains variation across populations of chimpanzees and orangutans. We conclude that strong mutual tolerance was a key factor in the explosive increase in technology among hominids, probably intricately tied to a lifestyle involving food sharing and tool-based processing or the acquisition of large, shareable food packages.

Animals↗
PubMed2001

Primates from Rudabánya: allocation of specimens to individuals, sex and age categories.

Fossil primates have been known from the late Miocene locality of Rudabánya since 1965. Numerous campaigns of collecting, sampling and excavation have been carried out since that time by several teams of researchers, but the sample of primates has never been fully catalogued and published. Here we provide a comprehensive list of all primate specimens from Rudabánya with provenience data and allocation to individuals. At the main locality of R II 16 individuals are attributed to Anapithecus and nine to Dryopithecus, based on dental remains. Anapithecus comes mostly from a layer of gray to black marl and Dryopithecus is found mostly in a less consolidated overlying black mud. However, both taxa are found in both layers. Anapithecus is represented by larger proportions of juveniles and females, and Dryopithecus by more adult and subadult males. Both species are represented primarily by dental remains, but those of Dryopithecus are more commonly associated with mandibles and maxillae, while in Anapithecus most individuals are represented by associated dentitions. Dryopithecus is better represented by postcrania other than phalanges. Anapithecus age and sex frequency distributions are more typical of those of carnivore and chimpanzee prey assemblages than Dryopithecus.

Age Factors↗
PubMed2002

Taxonomic variation in the patterns of craniofacial dimorphism in primates.

Understanding sexual dimorphism in living primates is important for interpreting the biological and taxonomic significance of variation in the primate fossil record. In the past two decades, there has been an increasing emphasis on the fact that sexual dimorphism varies in both magnitude and pattern among species. Several studies have suggested that distinct patterns of dimorphism may assist in species recognition and perhaps phylogenetic analysis. This study evaluates patterns of craniofacial dimorphism in samples of 82 anthropoid primates. Dimensions of the viscerocranium tend to be more dimorphic than those of the neurocranium and orbits. Principal components analysis of phylogenetically controlled data demonstrates a basic pattern of dimorphism in overall skull proportions, and a distinction between length and breadth measurements. For any given species there can be substantial variation in the magnitude of dimorphism among dimensions, and different species can show substantially different patterns of dimorphism within and between regions of the skull and jaws. Patterns of dimorphism are clearly associated with phylogeny. Pattern similarity is not dependent on the overall magnitude of craniofacial dimorphism, or body mass dimorphism. Among all anthropoids, there are few combinations of characters that consistently show greater or lesser degrees of dimorphism. Such "stability" of patterns increases within genera. Patterns of dimorphism are likely to be useful for interpreting the taxonomic significance of variation in the fossil record. However, phylogenetic propinquity alone is not reason to use an extant species as a model for variation in an extinct species. Rather, care must be taken to identify stable patterns of dimorphism within a group of closely related extant species.

Animals↗
PubMed2002

Primate canines from the early Miocene Pinturas Formation, Southern Argentina.

Previously undescribed canines from the Pinturas Formation (Santacrucian, early Miocene) in Patagonia, Argentina, indicate the presence of new primate taxa. These isolated teeth exhibit a generalized structure; the crowns are robust at the base, slightly or nonprojecting beyond the occlusal plane of the cheek teeth, with a relatively rounded or slightly sharp entocristid in the lowers. It is possible to distinguish at least one, possibly two, new primate genera. One taxon is slightly smaller than Soriacebus adrianae and morphologically distinct. The other may be an early relative of Alouatta, and if so it would expand the temporal and geographic range of this lineage. A third taxon is represented by an advanced pitheciin (? Soriacebus). Other isolated canines could be attributed to Carlocebus, but precise attribution remains uncertain. Despite the fragmentary nature of these specimens, and some unresolved taxonomic and phylogenetic questions, there is clear evidence for a greater diversity of fossil primates in Patagonia during the early Miocene than previously recognized.

Animals↗
PubMed1999

Origin and phylogenetic distribution of Alu DNA repeats: irreversible events in the evolution of primates.

Over the past 60 million years, or so, approximately one million copies of Alu DNA repeats have accumulated in the genome of primates, in what appears to be an ongoing process. We determined the phylogenetic distribution of specific Alu (and other) DNA repeats in the genome of several primates: human, chimpanzee, gorilla, orangutan, baboon, rhesus, and macaque. At the population level studied, the majority of the repeats was found to be fixed in the primate species. Our data suggest that new Alu elements arise in unique, irreversible events, in a mechanism that seems to preclude precise excision and loss. The same insertions did not arise independently in two species. Once inserted and genetically fixed, the DNA elements are retained in all descendant lineages. The irreversible expansion of Alu s introduces a vector of time into the evolutionary process, and provides realistic (rather than statistical) answers to questions on phylogenies. In contrast to point mutations, the present distribution of individual Alu s is congruent with just one phylogeny. We submit that only irreversible and taxonomically relevant events are at the molecular basis of evolution. Most point mutations do not belong to this category.

Alu Elements↗
PubMed1997

Evolution and selection of primate T cell antigen receptor BV8 gene subfamily.

The set of potential T cell receptor specificities is highly diverse. The relative contributions of T cell receptor (TCR) V beta gene segment polymorphisms, duplications, deletions, and gene conversions to this final T cell receptor protein diversity are unknown. To study these mechanisms, we sequenced and compared closely related primate TCR gene segments from BV8S1, S2, and S5. Interspecies comparisons show that these gene segments have sustained multiple duplication, gene conversion, and deletion events during the last 35 million years of anthropoid primate evolution. BV8 coding sequences are generally conserved with respect to their flanking noncoding sequences, but we find no evidence for positive or negative selection in sequences coding for the first two putative complementarity-determining (ligand-binding) regions. Sequences of TCRBV8 gene segments from unrelated humans demonstrate no nonsynonymous substitutions in nonleader regions of either the BV8S1 or S2 gene segments. We conclude that gene duplication, deletion, and conversion mechanism contribute in a substantial way to the overall diversity of the TCRBV8 gene segment repertoire in primate evolution and that germline substitutions and consequent polymorphisms in CDRs 1 and 2 of these gene segments probably do not play an active role in generating TCR beta chain protein variation.

Adult↗
PubMed1995

Mobilization of an ERV9 human endogenous retroviral element during primate evolution.

ERV9 is a low repeated family of human endogenous retroviral elements, which has close to 50 members, in addition to at least 4000 solitary LTRs. Previous work has shown that randomly selected LTRs can promote transcription of reporter genes, raising the possibility that these sequences may affect the expression of adjacent cellular genes. We report here the structural organization in different primate species of a zinc-finger coding gene whose expression is driven in humans by a solitary ERV9-LTR promoter. Using a PCR strategy and library screening, we were able to trace the origin of the insertion event in the primate lineage and to evaluate the impact of this event on gene structure. Our findings indicate that the integration of the ERV9 element occurred after the split of orangutang from the great apes, but before the divergence of the gorilla lineage. These results suggest that ERV9 elements have been mobile within the primate lineages and may still be active in humans.

Amino Acid Sequence↗
PubMed1996

Viral isolates derived from simian varicella epizootics are genetically related but are distinct from other primate herpesviruses.

Epizootics of a natural varicella-like disease occur in populations of nonhuman primates. Several primate herpesviruses have been isolated from these epizootics, but the relatedness of these isolates to each other is not well-defined. In this study, we demonstrated that the restriction endonuclease (REn) profiles of four epidemiologically distinct isolates were similar, although not identical, indicating that simian varicella epizootics are caused by various strains of simian varicella virus (SVV). The genetic variation among the isolates did not map to a specific region of the SVV genome and REn differences were detected within the SVV DNA long component and the inverted repeat region. Southern blot hybridization demonstrated that SVV is more closely related to varicella-zoster virus than to other primate herpesviruses. The study indicates that the current herpesvirus classification scheme should be changed to include SVV as a single taxonomic group within the Varicellovirus genus of alphaherpesviruses. In addition, REn profiles of SVV isolates, derived from primary and secondary episodes of simian varicella in the same monkey, were identical, providing evidence for SVV reactivation in a latently infected monkey.

Animals↗
PubMed1997

Endocrine control of germ cell proliferation in the primate testis. What do we really know?

The present chapter reviews current knowledge concerning hormonal regulation of gametogenesis in the primate testis. LH/testosterone and FSH are the prime regulators of primate spermatogenesis. Although either hormone is capable of stimulating all phases of the spermatogenic process including the formation of sperm, the combination of both hormones is necessary in most instances to achieve quantitatively normal germ cell numbers. Sertoli cell proliferation can also be induced by either hormone in juvenile monkeys. Evidence for differential effects of testosterone and FSH on gametogenesis, however, is lacking and a synergistic effect is observed when they are combined. Receptors for androgens and FSH occur exclusively on testicular somatic cells and, hence, the trophic effects of these hormones on germ cell numbers are indirect ones. Interestingly, both hormones seem to have a common target, the spermatogonial population but it is unknown how such an indirect albeit highly specific effect is mediated. Whether the trophic hormone action influences germ cell numbers via increased proliferation or decreased cell death or both remains to be seen. There is evidence to suggest that the local androgen requirements for primate spermatogenesis might be comparatively high.

Androgens↗
PubMed2003

Understanding xenotransplantation risks from nonhuman primate retroviruses.

Significant progress in making animal-to-human transplantation a viable adjunct to human organ donation will require a greater understanding of the intricacies of immunologic rejection. Recent success in generating cloned knockout piglets increases the possibility that xenotransplantation may find its way into the clinics. Nonhuman primates' organs have been used for human transplants in the past and there is reason to believe that if ethical considerations and inherent problems with supply were overcome, their close genetic proximity to humans would lessen complications of rejection. Unfortunately, nonhuman primates harbor several pathogens known to be infectious in humans and the potential of other viral infections has precluded further use of monkeys in this setting. Baboons are generally considered the nonhuman primate species of choice yet this species carries several retroviruses considered a threat to humans in transplantation. Both known and potentially undiscovered retroviruses pose an important risk that is the focus of this review.

Animals↗
PubMed1987

Isozymes as bioprobes for genetic analysis of nonhuman primates.

The identification and the utilization of genetically determined electrophoretic differences of enzymes between the individuals of species as well as between cell lines have played an important role in the advancement of mammalian genetics during the past quarter of a century. In an explicit search we found a number of red cell enzyme polymorphisms in each of the following four species: chimpanzees, orang utans, rhesus monkeys and brown capuchins. Allelic distribution patterns among populations have indicated trends of subspeciation among chimpanzees and orang utans due to geographic barriers leading to reproductive isolation. Investigations of quantitative levels of red cell glucose-6-phosphate dehydrogenase have suggested that relative activity profiles of certain enzymes among species may be helpful in studies of the evolution of physiological traits and their biological significance during speciation. A large number of biochemical genetic markers in primate-rodent (i.e., chimpanzee-, gorilla-, orang utan-, rhesus monkey- and African green monkey-Chinese hamster) somatic cell hybrids have been identified and are useful for primate genetic analysis. Some of the biologically relevant observations on the enzyme markers in the above mentioned primate species are discussed.

Animals↗
PubMed1987

Use of monoclonal antibodies in genetic research with nonhuman primates.

Monoclonal antibodies, because of their specificity and unlimited availability, have become one of the most powerful experimental tools available to the biological sciences. It is possible to make monoclonal antibodies that bind to determinants that are monomorphic in one or more species or to determinants that are polymorphic within a species. Few monoclonal antibodies have been made using immunogens derived from nonhuman primates. However, some monoclonal antibodies that recognize monotypic markers in humans can be used to detect polymorphic markers in nonhuman primates. Thus, the rapid development of monoclonal antibodies specific for human proteins significantly increases the potential number of immunogenetic markers useful for studying phylogenetic relationships and for identifying genetic polymorphisms among nonhuman primates.

Animals↗
PubMed1995

Microsatellite polymorphisms reveal phylogenetic relationships in primates.

We amplified, via PCR, DNA segments from intron 1 of the tyrosine hydroxylase gene (TH01) and intron 40 of the von Willebrand factor gene (VWA) in ten nonhuman primate genera. In humans both introns contain polymorphic microsatellites with tetrameric repeats. Compared to the allelic ranges in human populations relatively short repeat arrays could be detected for the nonhuman primates typed, presumably reflecting an ancient precursor state at both microsatellite loci. Furthermore, our results provide evidence for an association of the average number of repeats present in different primate genera and their divergence time from man. DNA sequencing of VWA orthologues revealed a relatively high variability in the arrangement of repeats in the 5'-repeat arrays, the generation of which could probably be explained by polar mutational events.

Animals↗
PubMed1994

C4 gene polymorphism in primates: evolution, generation, and Chido and Rodgers antigenicity.

Eleven new C4d genomic primate sequences of the fourth complement factor (C4) have been obtained. Seven of them belong to five species not yet explored for this gene: Pan paniscus (pygmy chimpanzee), Cercopithecus aethiops (green monkey), Macaca mulatta (rhesus monkey), Macaca fascicularis (cynomolgus), and Saguinus oedipus (cotton top tamarin). The New World monkeys (tamarins, four individuals) sequenced for C4 have a single C4d sequence only, which shows a B isotypic specificity and a Rodgers 3 (Rg3), Chido 1 (Ch1) antigenicity. Rg3 and Ch1 could thus be the oldest Rg/Ch specificity (at least 50 million years old) and Rg1, Rg2, Ch3, and Ch6 could be more recent human-specific antigens. Mechanisms of C4d polymorphism generation were analyzed by compiling all the presently available sequences. Examples of both point mutations and crossing-over events among C4d primate sequences could be detected. The problem of a possible trans-species inheritance of C4d polymorphism was addressed and two apparently contradicting dendrograms were obtained. One of them, constructed by using both exon and intron sequences, does not support trans-species evolution, but supports the proposed theory of extensive homogenization of the C4 genes occurring within each species, because alleles from each primate species cluster together. Another completely different dendrogram, obtained by using exon sequences only, suggests the existence of trans-species evolution for C4d polymorphism, because alleles belonging to different species cluster together in a way similar to that found for HLA class I or II alleles. However, orangutan sequences group together in both kinds of C4d sequence dendrograms and seem to have arisen from an ancestor different from that of chimpanzee, gorilla and man C4d sequences. Finally, further data have been obtained that support trans-species conservation of A-ness and B-ness and the existence of trans-specifically conserved allelic motifs, both in intronic and exonic sequences.

Amino Acid Sequence↗
PubMed1993

Evolution of protamine P1 genes in primates.

Protamine P1 genes have been sequenced by PCR amplification and direct DNA sequencing from 9 primates representing 5 major families, Cebidae (new world monkeys), Cercopithecidae (old world monkeys), Hylobatidae (gibbons), Pongidae (gorilla, orangutan, and chimpanzee), and Hominidae (human). In this recently diverged group of primates these genes are clearly orthologous but very variable, both at the DNA level and in their expressed amino acid sequences. The rate of variation amongst the protamine P1s indicates that they are amongst the most rapidly diverging polypeptides studied. However, some regions are conserved both in primates and generally in other placental mammals. These are the 13 N-terminal residues (including a region of alternating serine and arginine residues (the motif SRSR, res. 10-13) susceptible to Ser phosphorylation), a tract of six Arg residues (res. 24-29) in the center of the molecule, and a six-residue region (RCCRRR, res. 39-44), consisting of a pair of cysteines flanked by arginines. Detailed consideration of nearest-neighbor matrices and trees based on maximum parsimony indicates that P1 genes from humans, gorillas, and chimpanzees are very similar. The amino acid and nucleotide differences between humans and gorillas are fewer than those between humans and chimpanzees. This finding is at variance with data from DNA-DNA hybridization and extensive globin and mitochondrial DNA sequences which place human and chimpanzee as closest relatives in the super family, Hominoidea. This may be related to the fact that protamine P1s are expressed in germ line rather than somatic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗