Odour signals major histocompatibility complex genotype in an Old World monkey

The major histocompatibility complex (MHC) is an extraordinarily diverse cluster of genes that play a key role in the immune system. MHC gene products are also found in various body secretions, leading to the suggestion that MHC genotypes are linked to unique individual odourtypes that animals use to assess the suitability of other individuals as potential mates or social partners. We investigated the relationship between chemical odour profiles and genotype in a large, naturally reproducing population of mandrills, using gas chromatography–mass spectrometry and MHC genotyping. Odour profiles were not linked to the possession of particular MHC supertypes. Sex influenced some measures of odour diversity and dominance rank influenced some measures of odour diversity in males, but not in females. Odour similarity was strongly related to similarity at the MHC, and, in some cases, to pedigree relatedness. Our results suggest that odour provides both a cue of individual genetic quality and information against which the receiver can compare its own genotype to assess genetic similarity. These findings provide a potential mechanism underlying mate choice for genetic diversity and MHC similarity as well as kin selection.     

Victoriapithecus: The key to Old World monkey and catarrhine origins

The past ten years have witnessed major changes in reconstructions of the history of Old World monkeys, most of them driven by new material of the Miocene monkey Victoriapithecus from Maboko Island, Kenya. Before the mid-1980s, predictions about the morphological and ecological adaptations of the earliest cercopithecoids relied heavily on evidence from extant colobine and cercopithecine monkeys. It was argued that the earliest cercopithecoids were largely or at least partly folivorous, had short colobine-like faces, and were arboreal. The only studies suggesting that some of these arguments were not true were based on limited knowledge of the anatomy of Victoriapithecus. The presence of semi-terrestrial adaptations in middle Miocene monkeys hinted to some that early monkeys may not have been arboreal. Others attempted to cope with the discrepancy between neontological predictions and the fossil evidence by proposing that limb bones with stronger terrestrial adaptations within the Maboko sample were derived cercopithecine remains, while those with more arboreal features belonged in the subfamily Colobinae and should be regarded as primitive.     

The morula-blastocyst transition in two Old World primates: the baboon and rhesus monkey

Baboon and rhesus monkey embryos demonstrate compaction during the morula stage, although not all blastomeres participate simultaneously. During this process the outer adherent cells develop progressively more extensive apical junctional complexes. Several spaces appear between blastomeres before formation of a single cavity, and assortment of inner cell mass and trophoblast cells is less rapid and less precise in primates than in rodents. Nonhuman primates should prove appropriate for studies of individual aberrant blastomeres during blastocyst formation.     

Effective use of a joystick by an infant monkey

The acquisition of the ability to use a joystick to maintain contact between a cursor and moving target is described for an infant bonnet macaque (Macaca radiata). The infant was first exposed to a very elementary joystick task while living in a social group at the age of 3.5 months. With task difficulty increased in small increments over a total of only 9 weeks of access to the tasks, the infant was able to maintain contact with a small moving target for over 2.5 sec by the age of 7.5 months. © 1994 Wiley-Liss, Inc.     

Variation of the number of proximal caudal vertebrae with tail reduction in Old World monkeys

Tail length in primates can vary greatly between species or even between local conspecific populations, and the tail is markedly reduced in several lineages. In Old World monkeys, tail length is considered as an important feature reflecting their phylogeny and adaptations. The number of caudal vertebrae is one of the important factors which determine tail length, and it is known that this number varies with tail length. Caudal vertebrae can be divided into two types (proximal and distal), and tail mobility and function are considered to be different in these two regions. Though the number of vertebrae in each region is important for understanding tail length evolution in Old World monkeys, there have been few attempts to investigate this matter. This study focused only on the proximal caudal vertebrae, which are more easily preserved than the distal ones, and tested if there is variation in their number with tail length or phylogenic differences. As a result, two important findings were obtained: (1) the variation of the number of proximal caudal vertebrae was different among the phylogenic groups, and (2) especially in Papionini, there was a great variation in the number of proximal caudal vertebrae, and it correlated strongly with relative tail length [RTL = (tail length/head and body length (sitting height)) × 100 %]. I speculate that these variations in the number of proximal caudal vertebrae were possibly caused by a change of the embryonic developmental mechanism of tail morphogenesis, a common mechanism of morphological evolution. To clarify the mechanisms and evolutionary trends of the variation in the proximal caudal vertebrae, not only morphological approaches but also developmental biological approaches will be necessary in the future.     

Relative rates of nuclear DNA evolution in human and Old World monkey lineages

Rates of substitution were compared between humans and Old World monkeys for sequences in or adjacent to 19 genes. The comparison of 21,299 sites in noncoding regions indicates that the substitution rate is approximately 43% greater in the Old World monkey lineage. However, 83% of the compared sites are in the region of the beta-globin gene family. Outside this region there is no consistent pattern of rate difference between the two lineages. Comparison of the coding regions of 16 genomically dispersed genes, involving 1,592 synonymous sites and 5,275 nonsynonymous sites, showed a faster rate of substitution in the human lineage at the nonsynonymous sites of the prion gene, but otherwise no evidence of rate difference between the two lineages. It is concluded that rate differences between these two lineages may be specific to certain regions of the genome rather than being a general phenomenon. This conclusion needs to be confirmed by comparison of a larger number of genomically dispersed sequences. It is, however, consistent with the results of DNA-DNA hybridization experiments, which show no difference in evolutionary rate between the two lineages.      

Comparative large-scale propagation of retroviruses from Old World (Mason-Pfizer monkey virus) and New World (squirrel monkey virus) primates.

A cell culture method is described for the large-scale (50 to 150 1) production of Mason-Pfizer monkey virus and squirrel monkey virus, two primate retroviruses. Virus production was achieved with suspension cultures of chronically infected A204 human rhabdomyosarcoma cells harvested and clarified in the logarithmic stages of cell culture growth. Methods for the subsequent purification and concentration of virus material utilizing zonal centrifugation also are described. Applications of these methodologies resulted in products that afforded biochemical comparisons of these agents in a manner such that host cell-derived variations were minimized. These data indicated that high levels of production and efficient recovery and purification of virus material were achieved.     

The phylogeny of Old World monkeys

The living Old World monkeys, family Cercopithecidae, are the most successful group of nonhuman primates alive today. Overall, they account for over one quarter of the extant genera of primates and approximately 40% of the species. They have an extensive fossil record extending back to the early and middle Miocene of Africa.^1,2 Despite this specific diversity and a long evolutionary history, it is commonly argued that the group is relatively uniform in both its skeletal³ and dental⁴ anatomy, suggesting that much of the current taxonomic diversity is a relatively recent phenomenon. In such a species group, it is perhaps not surprising that the taxonomy of Old World monkeys is subject to many differing classifications. Thus, in recent years, authors have recognized as few as 10 and as many as 22 different genera within the family. Although some of this greater-than-two-fold difference in the number of genera can be attributed to the “splitting” versus “lumping” philosophies of different researchers, much of it is based on major disagreements over phylogenetic relationships. Recent studies of the genetics and chromosomes of this group have illuminated Old World monkey phylogeny in many ways. Some of these studies have resolved longstanding debates based on morphological data; others have revealed phylogenetic relationships that morphologists had never suspected.     

Maintenance of an Old World Betasatellite by a New World Helper Begomovirus and Possible Rapid Adaptation of the Betasatellite

Begomoviruses (family Geminiviridae) cause major losses to crops throughout the tropical regions of the world. Begomoviruses originating from the New World (NW) and the Old World (OW) are genetically distinct. Whereas the majority of OW begomoviruses have monopartite genomes and whereas most of these associate with a class of symptom-modulating satellites (known as betasatellites), the genomes of NW begomoviruses are exclusively bipartite and do not associate with satellites. Here, we show for the first time that a betasatellite (cotton leaf curl Multan betasatellite [CLCuMuB]) associated with a serious disease of cotton across southern Asia is capable of interacting with a NW begomovirus. In the presence of CLCuMuB, the symptoms of the NW cabbage leaf curl virus (CbLCuV) are enhanced in Nicotiana benthamiana. However, CbLCuV was unable to interact with a second betasatellite, chili leaf curl betasatellite. Although CbLCuV can transreplicate CLCuMuB, satellite accumulation levels in plants were low. However, progeny CLCuMuB isolated after just one round of infection with CbLCuV contained numerous mutations. Reinoculation of one such progeny CLCuMuB with CbLCuV to N. benthamiana yielded infections with significantly higher satellite DNA levels. This suggests that betasatellites can rapidly adapt for efficient transreplication by a new helper begomovirus, including begomoviruses originating from the NW. Although the precise mechanism of transreplication of betasatellites by begomoviruses remains unknown, an analysis of betasatellite mutants suggests that the sequence(s) required for maintenance of CLCuMuB by one of its cognate begomoviruses (cotton leaf curl Rajasthan virus) differs from the sequences required for maintenance by CbLCuV. The significance of these findings and, particularly, the threat that betasatellites pose to agriculture in the NW, are discussed.Viruses of the family Geminiviridae are distinct in having genomes of circular, single-stranded DNA (ssDNA) contained within twinned quasi-isometric (“geminate”) virions from which they derive their name. Geminiviruses are divided into four genera based on the organization of their genomes, biological properties, type of insect vector (either whitefly, leafhopper, or treehopper), and host range (either mono- or dicotyledonous hosts) (37). The genus Begomovirus contains the vast majority of the identified geminivirus species, and these are transmitted exclusively by the whitefly Bemisia tabaci (Gennadius) to dicotyledonous plants. All begomoviruses native to the New World (NW) and a small number originating from the Old World (OW) have bipartite genomes (with components known as DNA-A and DNA-B). The majority of the OW begomoviruses have genomes consisting of a single component homologous to the DNA-A component of the bipartite viruses. Begomoviruses from the NW and OW are genetically distinct. They segregate separately in phylogenetic analyses, and the OW viruses show a greater genetic diversity and have an additional, absolutely conserved gene (known as V2 for the monopartite and AV2 for the bipartite viruses) that is absent in the NW begomoviruses.The global trade in agricultural products is leading to the spread of many viruses. The prime example here is tomato yellow leaf curl virus. This monopartite begomovirus has its origins in the Middle East/Mediterranean region but has been inadvertently introduced to the NW, with serious consequences for tomato production across the southern United States (24, 26). Similarly, the NW begomovirus squash leaf curl virus from the southwestern United States has been introduced into the Middle East (2, 20).The majority of OW monopartite begomoviruses are associated with additional ssDNA molecules. The first evidence for this came with the report by Dry et al. (14) of an ssDNA satellite associated with tomato leaf curl virus (ToLCV) occurring in Australia. This molecule was later shown to be a defective (truncated) version of a much larger group of subviral components associated with begomoviruses that are now known collectively as betasatellites (6). Betasatellites are approximately half the size of a begomovirus component (∼1,360 nucleotides [nt]) and are required by the helper begomovirus for efficient infection of some hosts (9, 30, 31). Betasatellites have been shown to be associated with an increasing number of diseases caused by begomoviruses, including many of the most significant, economically damaging diseases occurring in the OW. The most noteworthy of these diseases is cotton leaf curl disease (CLCuD). CLCuD was epidemic during the 1990s across Pakistan and continues to be so in northern India. The disease is caused by a complex consisting of representatives of at least seven distinct begomovirus species and a specific betasatellite (23).Betasatellites have a highly conserved structure although their sequences are highly diverse, with distinct species showing as little as 50% sequence identity (6, 11, 42). They contain a single coding sequence (known as βC1), a region of sequence rich in adenine, and a ∼150-nt region, known as the satellite conserved region (SCR), that is highly conserved between all betasatellites. The SCR contains a predicted hairpin structure that contains within the loop a nonanucleotide sequence (TAATATTAC) that for geminiviruses marks the origin of virion-strand DNA replication. The βC1 gene is a pathogenicity determinant (27, 28, 33) and encodes all satellite functions identified so far, including suppression of RNA-mediated host defense (13) and possibly a role in virus movement (29). For many of the monopartite begomoviruses, the betasatellite is essential for inducing typical disease symptoms in the hosts from which they were isolated (6, 9, 30). However, recently some viruses with less dependence on interaction with their betasatellites have been identified (6).When betasatellites were first identified, their ability to interact with NW begomoviruses was investigated, but no evidence for interaction was found (R.W. Briddon, unpublished results). Here, we report a positive interaction between a betasatellite and the NW cabbage leaf curl virus (CbLCuV). We show that the interaction between the betasatellite and this NW begomovirus leads to rapid sequence changes in the satellite, which enhances its interaction with the virus.     

The status of the West African fish Gobius nigricinctus with reference to New World autochthones and an Old World colour-analogue

The systematic features of a small West African marine gobiid fish, Gobius nigricinctus Delais 1951, are redescribed from the holotype with special emphasis on the head lateral-line canal and sensory papillae (tree neuromast) systems. A junior synonym is found to be Gobius lepidogenys Robins 1970. The status of G. nigricinctus is best expressed in a new monotypic genus, Gorogobius , with closest affinity to the Atlantic-Mediterranean Corcyrogobius and Odondebuenia , Similarities in head sensory papillae arrangement exist between Gorogobius and certain 'seven-spined' genera of the New World tropical insular fauna, but G. nigricinctus is shown not to be a recent transatlantic immigrant. The validity of the tribe Gobiosomini as a natural grouping endemic to the Americas is questioned. Close resemblance in striped coloration between Gorogobius and small Indo-West Pacific gobies, especially Quisquilius eugenius , is shown to be the result of convergent evolution.     

Andromonoecy in an Old World Papilionoid legume,Erophaca baetica

Andromonoecy (i.e. the occurrence on individual plants of hermaphroditic and male flowers) is a rare sexual system among the angiosperms, regarded by some authors as a transitional stage from hermaphroditism to monoecy. Having discovered the occurrence of andromonoecy in Erophaca baetica (a Mediterranean shrubby legume with two subspecies), a novelty for Old World papilionoid legumes, we investigated the morpho‐functional correlates and the geographical distribution of this phenomenon in the species. The relative frequencies of hermaphrodite and male flowers were determined in two field and 111 herbarium populations. Biomass allocation within flowers, pollen production and viability, pollen tube growth, nectar production and the temporal pattern of male flower production were also studied in two nearby southern Spanish populations. Virtually all of the studied populations were andromonoecious. Male flowers tended to appear at apical positions within the inflorescence, and became more abundant by the end of the flowering season. Male flowers were externally similar to hermaphroditic flowers (although with less biomass and smaller parts) and released equivalent amounts of pollen and nectar; however, their pollen germinated significantly better. Erophaca is the first example of an andromonecious Papilionoid in the Old World. Since the main difference among floral morphs in this species is functional (i.e. pollen germination rate) rather than morphological, andromonoecy is not readily noticeable, and very careful inspection may be required to reveal it. The potential effect of andromonoecy in enhancing outcrossing rate in this species is discussed.     

Different mechanisms of cell entry by human-pathogenic Old World and New World arenaviruses

The Old World arenavirus Lassa virus (LASV) is the causative agent of severe viral hemorrhagic fever (VHF) in humans and is the most prevalent human pathogen among arenaviruses. The present study investigated the largely unknown mechanisms of cell entry of LASV, a process know to be mediated solely by the virus envelope glycoprotein (GP). To circumvent biosafety restrictions associated with the use of live LASV, we used reverse genetics to generate a recombinant variant of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) expressing the LASV GP (rLCMV-LASVGP). The rescued rLCMV-LASVGP grew to titers comparable to that of LCMV and showed the receptor binding characteristics of LASV. We used rLCMV-LASVGP to characterize the cellular mechanisms of LASV entry in the context of a productive arenavirus infection. The kinetics of pH-dependent membrane fusion of rLCMV-LASVGP resembled those of the human-pathogenic New World arenavirus Junin virus (JUNV) and other enveloped viruses that use clathrin-mediated endocytosis for entry. However, rLCMV-LASVGP entered cells predominantly via a clathrin-, caveolin-, and dynamin-independent endocytotic pathway similar to the one recently described for LCMV. Productive infection of rLCMV-LASVGP was only mildly affected by a dominant negative mutant of Rab5 and was independent of Rab7, suggesting an unusual mechanism of delivery to endosomes. In addition, rLCMV-LASVGP infection was independent of actin but required intact microtubules. Our data indicate that LASV enters cells via a pathway distinct from the one used by human-pathogenic New World arenaviruses.