African Green Monkey Subspecies Research Articles

The Host Restriction Factor APOBEC3G and Retroviral Vif Protein Coevolve due to Ongoing Genetic Conflict

APOBEC3G (A3G) is a host cytidine deaminase that inhibits retroviruses. HIV and related primate lentiviruses encode Vif, which counteracts A3G by inducing its degradation. This Vif-mediated A3G inhibition is species specific, suggesting that the A3G-Vif interaction has evolved as primate lentiviruses have adapted to their hosts. We examined the evolutionary dynamics of the A3G-Vif interaction within four African green monkey (AGM) subspecies, which are each naturally infected with a distinct simian immunodeficiency virus (SIV). We identified single amino acid changes within A3G in two AGM subspecies that render it resistant to Vif proteins, except for Vif from the viruses that naturally infect these subspecies. Moreover, experimental infection of AGMs shows that Vif can rapidly adapt to these arising Vif-resistant A3G genotypes. These data suggest that despite being generally nonpathogenic in its natural host, SIV infection selects for Vif-resistant forms of A3G in AGM populations, driving Vif counterevolution and functional divergence.

Advances in HIV molecular biology

Advances in HIV molecular biology

Phylogenetic Analysis of Simian T-lymphotropic Virus Type I (STLV-I) in Common Chimpanzees (Pan troglodytes): Evidence for Interspecies Transmission of the Virus between Chimpanzees and Humans in Central Africa

Serum and peripheral blood leukocytes from the chimpanzees (Pan troglodytes) of the colony of the Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, NIH, were tested for the presence of STLV-I-specific antibodies and proviral DNA. Antibodies were determined by gelatin particle agglutination and Western blot (WB) assays utilizing HTLV-I antigens. Proviral DNA was detected by four PCR assays targeting three different regions of STLV-I genome: the fragments of theenvandpolgenes andLTR.Twenty of twenty-two DNA samples from WB-positive animals were PCR positive. None of the DNA samples from WB-negative (n= 5) and WB-indeterminate (n= 4) animals was PCR positive. The results of the nested and double nestedenvPCR tests were fully concordant; the seminestedLTRPCR test was much less sensitive. The DNA sequences from theenv(483 bp) and thepol(200 bp) genes andLTR(705 bp) were determined for six, two, and two chimpanzee STLV-I isolates, respectively. Phylogenetic analysis revealed that chimpanzee STLV-I isolates can be attributed to three clades. The first of these clades (SS-PTR1/CSA) included STLV-I isolates from the chimpanzees and West African subspecies of African green monkeys (Cercopithecus a. sabaeus). The other clades (S-PTR2 and S-PTR3) included STLV-I isolates only from chimpanzees. However, both S-PTR2 and S-PTR3 clustered together with Central African HTLV-I comprising the human/simian clade (HS-HSA/PTR). This pattern of phylogenetic clustering suggests that interspecies transmission of STLV-I occurred between chimpanzees and African green monkey subspecies as well between chimpanzees and human populations in Central Africa.

St. Kitts green monkeys originate from West Africa: Genetic evidence from feces.

Sequencing of a fragment of mitochondrial DNA extracted from droppings of a green monkey inhabiting the Caribbean island of St. Kitts, and comparing the obtained sequence with sequences determined earlier for the four recognized subspecies of African green monkeys, showed that this monkey can be classified as Cercopithecus aethiops sabaeus, and thus originates from West Africa. As the ancestors of the monkeys reached the island by ships involved in the slave trade in the 17th to 18th centuries, determination of the monkey subspecies suggests that the animals were originally acquired nearby the West African ports from which the ships sailed, and were not brought from the central parts of Africa together with the slaves. © 1996 Wiley-Liss, Inc.

Phylogeny and natural history of the primate lentiviruses, SIV and HIV

Studies of primate lentivirus phylogeny over the past decade have established a minimum of five related, but genetically distinct, groups of simian immunodeficiency virus (SIV), each originating from a different African primate species. The hypothesis that HIV-2 (and SIVmac) arose by cross-species transmission from sooty mangabeys ( Cercocebus atys has been strengthened by a more detailed characterization of the SIVsm/SIVmac/HIV-2 group of viruses. SIV from all four subspecies of African green monkeys (SIVagm) have been characterized with an apparent chimeric genome structure of SIVagm from west African green monkeys. Although these naturally infected primates remain healthy, cross-species transmission to other primate species may result in immunodeficiency, as caused by SIVsm infection of macaque monkeys ( Macaca sp.) and recently, SIVagm infection of pig-tailed macaques ( M. nemestrina). Studies of variation within infected individuals have been facilitated by adaptation of the techniques of heteroduplex analysis and single-stranded conformational polymorphism of PCR generated fragments.

Isolation and Characterization of Simian Immunodeficiency Viruses from Two Subspecies of African Green Monkeys

Cercopithecus aethiops (African Green monkey), a nonhuman primate species distributed throughout subsaharan Africa, has been shown to have high seroprevalence rates of antibodies to simian immunodeficiency virus (SIV), and therefore, has been proposed as a natural reservoir for immunodeficiency viruses. Our laboratories have isolated SIV-like viruses from two East African subspecies of C. aethiops designated grivet and vervet monkeys. Analysis of the structural proteins based on the molecular weights and immunologic cross-reactivity to the prototypic SIV(MAC), HIV-1, and HIV-2 isolates suggests that these viruses are distinctly different. Heterogeneity was observed in the molecular weights of the gag, pol, and env gene products between SIV isolates from vervets [SIV(AGM(VER))] and grivets [SIV(AGM(GRI))]. Phenotypically, SIV(AGM(VER)) isolates were distinguishable from SIV(AGM(GRI)) isolates by the apparent size difference of the major core antigen p24. All SIV(AGM(GRI)) and SIV(AGM(VER)) isolates were found to encode a transmembrane protein of approximately 40 kD (gp40) in contrast to gp32 of SIV(MAC). Furthermore, the transmembrane protein was shown to be encoded by the entire env open reading frame, unlike gp32 of SIC(MAC) or gp36 of SIV(AGM(TYO-1)). These data indicate that viruses from C. aethiops share common features with SIV(MAC) and HIV-1, but represent diverse SIV-like viruses which may vary according to subspecies and geographic location.

Development of a nonhuman primate model for spontaneous hypertension. Blood pressures in first-generation offspring.

A breeding colony of two subspecies of African green monkeys has been established in an attempt to develop a strain of nonhuman primates with inherited spontaneous hypertension. Selective breeding of normotensive and hypertensive feral animals has produced over 300 first-generation, colony-born offspring of nine possible types, which were grouped according to parentage. Blood pressures were measured by indirect methods in 335 unanesthetized animals aged 0.5 to 6 years. Analysis of variance and covariance of mean blood pressures of animals aged 0.5 to 6 years indicated significant differences between control and experimental offspring groups (p less than .001) both before and after adjusting for sex, subspecies, age, and body weight. Mean blood pressures of control and experimental (p less than .02) offspring were significantly different from 0.5 to 5 years of age. The slopes of the regression of mean blood pressure on age were significantly different between the control and experimental groups (p less than .001). Multiple linear regression analysis indicated significant differences among blood pressure, body weight, and age (p less than .001) and also between age and weight (p less than .001) between the groups. The relative contributions of age and weight to determining the mean blood pressure differed, however. The results indicate that elevated blood pressures can be detected in offspring with even one parent having elevated blood pressure from as early as 1 year of age and that the tendency to develop elevated blood pressure is transmitted from parent to offspring in this species, thereby providing a strong indication that a hypertensive strain of monkeys can be developed through selective breeding.

Nutritional effects on blood lipid and HDL cholesterol concentrations in two subspecies of African green monkeys (Cercopithecus aethiops).

The African green monkey has previously been found to be a promising model for the study of atherosclerosis. We have compared the plasma and HDL cholesterol response to dietary manipulation in the two subspecies of African green monkeys (vervets and grivets) most often imported for biomedical research purposes. Twenty vervets and 20 grivets were fed, in succession, diets containing safflower oil, butter, or lard as the principal dietary fat at a level of 40% of calories. Ten animals of each subspecies were fed the diets without added cholesterol (control groups) and 10 were fed diets with either added crystalline cholesterol (safflower oil and butter diets) or egg yolk (lard diet) to raise the diet cholesterol level at least five-fold. The effect of the type of dietary fat was that total plasma cholesterol (TPC) and HDL cholesterol concentrations were lowest while the safflower oil diet was fed, were significantly higher when butter fat diets were fed, and were highest when the egg yolk-lard based diets were fed. In addition, a significant effect of the elevated level of dietary cholesterol, independent of the type of dietary fat, was seen: a statistically significant negative correlation between TPC and HDL cholesterol concentrations was induced. In contrast, a positive correlation between TPC and HDL cholesterol concentrations was found at the lower dietary cholesterol level. Thus, the different factors (type of fat versus cholesterol) influenced lipoprotein metabolism in distinct yet related ways. Although average values for both plasma and HDL cholesterol concentrations were significantly higher in the grivet subspecies than in the vervet subspecies, the data for both subspecies fit the same regression lines. This outcome suggested that the subspecies differed in the magnitude of response rather than in the mechanism of response.