Evolution comparée du gène transferrine chez l'homme et les primates,par hybridation après transfert avec une sonde spécifique

Hybridization of an human transferring gene probe with DNAs of Man and several Primates digested by various endonucleases reveals homologous restriction fragments between the different species. Comparisons based on restriction fragment lengths, numbers and intensities show regularity in the variation of this gene with the different grades of Primate evolution.     

An evolution revolution provides further revelation

The extent of copy-number variation (CNV) in the human genome has been appreciated only recently. Nevertheless, for almost four decades, gene duplication has been a prevailing hypothesis for evolutionary change. Recently, gene CNV spanning 60 million years of human and primate evolution has been determined enabling lineage-specific gene CNV to be identified. Primate lineage-specific gene CNV studies reveal that almost one third of all human genes exhibit a copy-number change in one or more primate species. Intriguingly, human lineage-specific gene amplification can be correlated to the emergence of human-specific traits such as cognition and endurance running.     

Primate cranium morphology through ontogenesis and phylogenesis,factorial analysis of global variation

Factorial analysis of Primate cranial morphology describes variation of the Order in postnatal growth, and shows the positions of some fossil specimens relative to present species.     

Genetic correlations between mandibular molar cusp areas in baboons

Primate evolutionary studies rely significantly on dental variation given the large role that teeth play in how an organism interacts with its environment (animal and plant) and conspecifics. Variation in cusp size has been shown to vary among primate taxa, although most studies to date focused on extant and extinct hominoids. Here we test the assumed hypothesis that a significant proportion of this variation in baboons is due to the additive effects of genes. We perform quantitative genetic analyses on variation in two-dimensional (2-D) mandibular molar cusp size in a captive pedigreed breeding population of baboons (Papio hamadryas) from the Southwest National Primate Research Center. These analyses show that variation in cusp size is heritable and sexually dimorphic. Additionally, we tested for genetic correlations between cusps on the same crown, between morphological homologues along the tooth row, and between cusp area and crown buccolingual width. We find that four of the six cusp pairs on the first molar have a genetic correlation of one, save for the metaconid-hypoconid and entoconid-hypoconid, which are not statistically different from zero. The second and third molars have lower genetic correlations, although the metaconid-hypoconid correlation is similarly estimated at zero and the entoconid-protoconid correlation is estimated to be one. This cross pattern of genetic and no genetic correlation does not immediately accord with the known pattern of development and/or calcification. We propose two explanative hypotheses.     

Lentiviral vectors: excellent tools for experimental gene transfer and promising candidates for gene therapy

Lentiviral vectors are tools for gene transfer derived from lentiviruses. From their first application to now they have been strongly developed in design, in biosafety and in their ability of transgene expression into target cells. Primate and non-primate derived lentiviral vectors are now available and with both types of systems a lot of studies tuned to improve their performances in a large number of tissues are ongoing. Here we review the state of the art of lentiviral vector systems discussing their potential for gene therapy.     

Nonhuman primates are relevant models for research in hematology, immunology and virology

Nonhuman primates have been used for biomedical research for several decades. They have proved to be models that are relevant to humans because of the high level of gene homology which underlies physiological and biochemical similarities. The similarity of monkeys to humans has been used to investigate pathophysiological mechanisms in hematology, immunology and virology. New therapeutic procedures can be assessed in primates by using materials, in particular pharmacological reagents, and methods designed for humans. The relevance of these models also relies on the use of species-specific pathogens and the availability of recombinant, homologous cytokines. The introduction of more and more sophisticated cell and gene therapy protocols in hematopoietic cell transplantation and immunotherapy requires the development of preclinical trials similar to clinical settings. For several decades now, baboons and cynomolgus/rhesus monkeys have been the most useful primate models in experimental hematology, and this has contributed to numerous therapeutic advances. Primate models of AIDS have been developed to study the pathogenesis, transmission and immune responses to infection, and to test vaccines and drugs. Primate research should be restricted in quantity, and mainly designed with the aim of removing uncertainty as to the safety and clinical benefit to the patient, of new biomedical protocols.     

Counting primates for conservation: primate surveys in Uganda

Primate census techniques have been developed over the past 35–40 years yet there is still some confusion and great variation in the methods used. This precludes comparisons between sites where different techniques have been used. This paper discusses the variations between the methods that seem to be practiced currently and then describes a census of primates in the forests of western Uganda. Primate density and biomass varied greatly between forests as well as within forests and this is probably related to food availability. Chimpanzee (Pan troglodytes) density was strongly correlated with nest encounter rates from reconnaissance walks in the forest. This result can be used to estimate chimpanzee density in forests where it is difficult to survey this species (e.g., due to security reasons). A total of 4,980 chimpanzee was estimated for Uganda which is higher than previously guessed, but still of conservation concern. Only four forests had more than 500 individuals which gives concern for long-term population viability.     

Statistical genetics of molar cusp patterning in pedigreed baboons: implications for primate dental development and evolution

Gene expression and knock-out studies provide considerable information about the genetic mechanisms required for tooth organogenesis. Quantitative genetic studies of normal phenotypic variation are complementary to these developmental studies and may help elucidate the genes and mechanisms that contribute to the normal population-level phenotypic variation upon which selection acts. Here we present the first quantitative genetic analysis of molar cusp positioning in mammals. We analyzed quantitative measures of molar cusp position in a captive pedigreed baboon breeding colony housed at the Southwest National Primate Research Center in San Antonio, Texas. Our results reveal complete pleiotropy between antimeric pairs of traits--i.e., they are influenced by the same gene or suite of genes. Mandibular morphological homologues in the molar series also exhibit complete pleiotropy. In contrast, morphological homologues in maxillary molar series appear to be influenced by partial, incomplete pleiotropic effects. Variation in the mandibular mesial and distal molar loph orientation on the same molar crown is estimated to be genetically independent, whereas the maxillary molar mesial and distal loph orientation is estimated to have partially overlapping genetic affects. The differences between the maxillary and mandibular molar patterning, and the degree of genetic independence found between lophs on the same molar crown, may be indicative of previously unrecognized levels of modularity in the primate dentition.     

The Japanese Tsukuba Primate Center for Medical Science (TPC): an outline

The facilities and activities of the Japanese Primate Center at Tsukuba, Japan are described. The Center became partially functional in 1978 and was completed in 1979. The three main aims of the Primate Center are: to quarantine newly imported primate animals, to breed, and to study them.     

The Primate Anthology: Essays on Primate Behavior, Ecology, and Conservation from Natural History

The Primate Anthology: Essays on Primate Behavior, Ecology, and Conservation from Natural History. Russell L. Ciochon and Richard A. Nisbett. eds. Upper Saddle River, NJ: Prentice Hall, 1998. 246 pp.     

Use of nonhuman primates in cancer research

A short historical review of the use of primates in cancer research is presented followed by a review of various forms of neoplasma observed in the oldest existing Primate Center. Special attention is paid to baboon lymphomas studied for the past two decades at the U.S.S.R. Primate Center at Sukhumi.     

Ecological correlates of abundance in the Tana mangabey (Cercocebus galeritus)

I investigated the ecological correlates of abundance in the Tana mangabey (Cercocebus galeritus), one of the world's most endangered primates, with the goal of recommending management strategies. I systematically selected 31 forest fragments throughout the mangabey's 60-km distribution along the lower Tana River in southeastern Kenya. Within the 31 fragments, I measured vegetation structure, food abundance, and human forest product use in 107 belt transects, and conducted 370 mangabey surveys. I used a weighted multiple regression analysis to determine whether there was a dependence between the selected forest attributes and the mean number of mangabey groups per fragment. Fragment area and density of trees > or =10 cm diameter at breast height (DBH) were the only variables that significantly correlated with the variation in mangabey abundance. No additional variables were significant when the analysis was limited to forest fragments inside the Tana River Primate National Reserve (TRPNR) or to fragments outside the TRPNR. When I estimated the resources available before recent human forest product use by adding nonharvested and harvested variables, the total basal area of the top 15 food species became significant. This was only within the TRPNR, however. Management, therefore, should focus on increasing forest area, density of trees > or =10 cm DBH, and coverage of food trees throughout the mangabey's distribution. Solutions must be found for the problem of forest clearing, and forest product use must be better managed to protect the habitat of this critically endangered primate. The significance of food abundance only within the TRPNR suggests a need to collect dietary data from mangabey groups in fragments toward the southern limit of the mangabey's distribution, where plant species composition differs from that in fragments in which dietary data have been previously collected.     

Efficiency of homologous intermolecular recombination at different locations on the Bacillus subtilis chromosome.

The efficiencies of intermolecular recombination at 12 different locations on the Bacillus subtilis chromosome were determined by transforming competent cells with a nonreplicative plasmid. The efficiencies varied by only about threefold but were significantly different (P less than 0.05 by a chi-square test) for approximately 20% of the locations. The recA gene product is required for recombination, and the addA gene product appears to affect the variation in a site-specific way.     

Gestation length in rhesus macaques (Macaca mulatta)

We describe some of the sources of variation in gestation length among rhesus macaques. the data were obtained from the timed-mating breeding program at the California Regional Primate Research Center (CRPRC). Information about approximately 700 pregnancies that resulted in spontaneous vaginal deliveries of liveborn young is presented. The average length of these pregnancies was 166.5 days. In this population, older females with higher parities had significantly longer pregnancies and significantly heavier infants than other females did. Other factors, including infant sex, month of conception, maternal reproductive history, and paternal identity, had no consistent effect upon gestation length.     

Milk composition varies in relation to the presence and abundance of Balantidium coli in the mother in captive rhesus macaques (Macaca mulatta)

Primate infants require extensive maternal investment, and lactation is the most expensive aspect of this investment. However, the relationship between maternal condition and milk composition has been largely uninvestigated in primates. To better understand this relationship, I collected mid-lactation milk samples from 46 captive multiparous rhesus macaques (Macaca mulatta) at the Caribbean Primate Research Center, Sabana Seca Field Station, Puerto Rico. The maternal variables assessed were age, weight, weight for crown-rump length (CRL), and presence of parasites. Additionally the analysis included infant age, weight, and sex. Protein concentration in milk showed little interindividual variation, whereas fat had a high variance. Mothers without the lower intestinal parasite Balantidium coli had a significantly higher fat concentration in milk than mothers with B. coli, but other parasite species (Trichuris trichiura and Strongyloides fulleborni) were not associated with milk fat concentration. Females with younger infants had a higher fat concentration in their milk than mothers with older infants; however, the association between B. coli and milk fat remained significant after controlling for infant age. These results, obtained from a well fed captive population, indicate that even small differences among mothers are associated with milk composition.     

Evolution of genetically correlated traits: tooth size and body size in baboons

Within a population, only phenotypic variation that is influenced by genes will respond to selection. Genes with pleiotropic effects are known to influence numerous traits, complicating our understanding of their evolution through time. Here we use quantitative genetic analyses to identify and estimate the shared genetic effects between molar size and trunk length in a pedigreed, breeding population of baboons housed at the Southwest National Primate Research Center. While crown area has a genetic correlation with trunk length, specific linear measurements yield different results. We find that variation in molar buccolingual width and trunk length is influenced by overlapping additive genetic effects. In contrast, mesiodistal molar length appears to be genetically independent of body size. This is the first study to demonstrate a significant genetic correlation between tooth size and body size in primates. The evolutionary implications are discussed.     

Genomic organization and expression of Campylobacter flagellin genes.

Campylobacter coli VC167, which undergoes an antigenic flagellar variation, contains two full-length flagellin genes, flaA and flaB, that are located adjacent to one another in a tandem orientation and are 91.5% homologous. The gene product of flaB, which has an Mr of 58,946, has 93% sequence homology to the gene product of flaA, which has an Mr of 58,916 (S. M. Logan, T. J. Trust, and P. Guerry, J. Bacteriol. 171:3031-3038, 1989). Mutational analyses and primer extension experiments indicated that the two genes are transcribed under the control of distinct promoters but that they are expressed concomitantly in the same cell, regardless of the antigenic phase of flagella being produced. The flaA gene, which was expressed at higher levels than the flaB gene in both phases, was transcribed from a typical sigma 28-type promoter, whereas the flaB promoter was unusual. A mutant producing only the flaB gene product did not synthesize a flagellar filament and was nonmotile. Southern blot analysis indicated that flagellar antigenic variation involves a rearrangement of flagellin sequence information rather than the alternate expression of the two distinct genes.     

灵长类比较基因组学的研究进展

随着人类和黑猩猩全基因组测序工作宣布完成,以及其他灵长类基因组测序工作的逐步开展,目前已经积累了大量的灵长类基因组数据,一个崭新的研究领域——灵长类比较基因组学应运而生。该文主要通过对人类和其他非人灵长类系统关系和基因组结构的比较,从系统进化、基因组结构和基因表达调控等方面评述该领域的研究进展,阐述人类、黑猩猩与其他非人灵长类之间的主要生物学差异,揭示人类进化的生物学机制。     

Morphological Variation in Wild Marmosets (Callithrix penicillata and C. geoffroyi) and Their Hybrids

Evolutionary theory and observation predict wider phenotypic variation in hybrids than parental species. Emergent phenotypic novelty in hybrids may in turn drive new adaptations or speciation by breaking parental phenotypic constraints. Primate hybridization is often documented through genetic evidence, but knowledge about the primate hybrid phenotype remains limited due to a small number of available studies on hybrid primate morphology. Here, we examine pelage and morphometric variation in two Brazilian marmoset species (Callithrix penicillata and C. geoffroyi) and their hybrids. Hybrids were sampled in an anthropogenic hybrid zone in the municipality of Viçosa, Minas Gerais state, Brazil. We analyzed hybrid facial and body pelage color variation, and compared 13 morphometric measures between hybrids and parental species. Five different hybrid facial morphotypes were observed, varying from intermediate to parental-like. Hybrid facial morphotypes were biased towards C. penicillata, suggesting that the pelage of this species may be dominant to that of C. geoffroyi in this context, and indicating that mate preference, and therefore gene flow/introgression, may be biased towards C. penicillata within the hybrid zone. Hybrid morphometric features were on average intermediate to parental species traits, but transgressive hybrids were also observed, suggesting that morphometric variation for the studied traits is consistent with Rieseberg’s complementary allele model. Finally, we observed a decoupling of facial patterning and size/shape in hybrids, relative to parent phenotypes, suggesting that an important factor driving phenotypic novelty within the Viçosa marmoset hybrid zone might be the loosening of evolutionary constraints on phenotypic trait integration.     

Park or Ride? Evolution of Infant Carrying in Primates

Few mammalian orders carry their infants clinging to the mother's fur. I investigated the evolution of carrying behavior in primates and the life-history and ecological correlates of infant care patterns. Primates are ideal for the study as there is variation in infant care patterns. Primate infants are left hidden in nests or parked in trees, both of which strategies I term parking, and are carried orally or ride clinging to the mother's fur: riding. Infant carrying has evolved several times in the Primates and, once evolved, it has been conserved. Significant energetic costs of riding are indicated as riding species maintain smaller home ranges than those of non-riders of the same body size. With body size and phylogenetic influences taken into account, riders appear to incur a reproductive cost by weaning and breeding later than parkers. Although riders do not have lower birth rates than those of parkers, their later age at first reproduction leads to their having a lower reproductive rate, measured by the intrinsic rate of population increase. Precociality of infants is not correlated with either riding or nesting behavior. Although non-nesting species have larger litter sizes, their infants are not significantly smaller, nor are their neonatal brains relatively smaller. Although riding may have some energetic and reproductive costs, its repeated evolution in the Primates suggests that it also has some benefits, the most likely being a reduced mortality risk for carried infants.