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PubMed1988

Sequence of simian immunodeficiency virus from African green monkey, a new member of the HIV/SIV group.

Some wild African green monkeys are known to be naturally infected with a retrovirus related to human immunodeficiency virus (HIV) without having any apparent symptoms of an AIDS-like disease. This simian immunodeficiency virus, designated SIVAGM, may be helpful in clarifying the evolution and pathogenicity of HIV. Some virus strains that were previously reported to be isolated from African green monkeys were shown to be laboratory contaminations of SIVMAC (SIV from a rhesus macaque) Here we report the complete DNA sequence of authentic SIVAGM, which was isolated from a naturally infected African green monkey of Kenyan origin. Comparison of the genome of SIVAGM with those of known HIV/SIVs indicates that the virus is a new simian lentivirus that is approximately equally distantly related to HIV-1 and HIV-2 in contrast to SIVMAC, which is much closer to HIV-2 than to HIV-1 (refs 5, 9).

Amino Acid Sequence↗
PubMed2001

Ecological importance of trichromatic vision to primates.

Trichromatic colour vision, characterized by three retinal photopigments tuned to peak wavelengths of approximately 430 nm, approximately 535 nm and approximately 562 nm (refs 1, 2), has evolved convergently in catarrhine primates and one genus of New World monkey, the howlers (genus Alouatta). This uniform capacity to discriminate red-green colours, which is not found in other mammals, has been proposed as advantageous for the long-range detection of either ripe fruits or young leaves (which frequently flush red in the tropics) against a background of mature foliage. Here we show that four trichromatic primate species in Kibale Forest, Uganda, eat leaves that are colour discriminated only by red-greenness, a colour axis correlated with high protein levels and low toughness. Despite their divergent digestive systems, these primates have no significant interspecific differences in leaf colour selection. In contrast, eaten fruits were generally discriminated from mature leaves on both red-green and yellow-blue channels and also by their luminance, with a significant difference between chimpanzees and monkeys in fruit colour choice. Our results implicate leaf consumption, a critical food resource when fruit is scarce, as having unique value in maintaining trichromacy in catarrhines.

Adaptation, Biological↗
PubMed1992

The spatial arrangement of cones in the primate fovea.

The retinae of Old World primates contain three classes of light-sensitive cone, which exhibit peak absorption in different spectral regions. But how are the different types of cone arranged in the hexagonal mosaic of the fovea? This question has often been answered with artists' impressions, but never with direct measurements. Staining for antibodies specific to the short-wave photopigment has revealed a sparse, semiregular array of cones; but nothing is known about the arrangement of the more numerous long- and middle-wave cones. Are they randomly distributed, with chance aggregations of one type, as Hartridge postulated in these columns nearly 50 years ago? Or do they exhibit a regular alteration, recalling the systematic mosaics seen in some non-mammalian species? Or, conversely, is there positive clumping of particular cone types, as might be expected if local patches of cones were descended from a single precursor cell? We have made direct microspectrophotometric measurements of patches of foveal retina from Old World monkeys, and report here that the distribution of long- and middle-wave cones is locally random. These two cone types are present in almost equal numbers, and not in the ratio of 2:1 that has been postulated for the human fovea.

Animals↗
PubMedDate not supplied

Hemagglutination inhibition studies for the evaluation of blood group antigens in ethanol soluble substances (ESS) obtained from human, baboon and vervet monkey red blood cells.

Soluble blood group substances, isolated from the red blood cells of humans, baboons, and vervet monkeys by ethanol extraction, possessed serologically active specificities for the following antigens: A, B, H, Lea, LebL, P, P19 Pk and I. Human red blood cells lacking any of these specificities by the direct hemagglutination test also lacked the related antigens in their soluble extract. The only exception was in "Bombay" Oh cells, from which soluble H substance could be readily isolated. Soluble substances obtained from baboon and vervet monkey red blood cells, which lack the human variety of A, B, and H antigens on their red blood cells, inhibited both human and lectin anti-H reagents. The detection of "hidden" H activity in Oh cells will pose some important questions regarding membrane characteristics and the role of immune surveilance.

ABO Blood-Group System↗
PubMed1979

Rapid evolution of animal mitochondrial DNA.

Mitochondrial DNA was purified from four species of higher primates (Guinea baboon, rhesus macaque, guenon, and human) and digested with 11 restriction endonucleases. A cleavage map was constructed for the mitochondrial DNA of each species. Comparison of the maps, aligned with respect to the origin and direction of DNA replication, revealed that the species differ from one another at most of the cleavage sites. The degree of divergence in nucleotide sequence at these sites was calculated from the fraction of cleavage sites shared by each pair of species. By plotting the degree of divergence in mitochondrial DNA against time of divergence, the rate of base substitution could be calculated from the initial slope of the curve. The value obtained, 0.02 substitutions per base pair per million years, was compared with the value for single-copy nuclear DNA. The rate of evolution of the mitochondrial genome appears to exceed that of the single-copy fraction of the nuclear genome by a factor of about 10. This high rate may be due, in part, to an elevated rate of mutation in mitochondrial DNA. Because of the high rate of evolution, mitochondrial DNA is likely to be an extremely useful molecule to employ for high-resolution analysis of the evolutionary process.

Animals↗
PubMed1981

DNA sequences similar to those around the simian virus 40 origin of replication are present in the monkey genome.

We report the molecular cloning of African green monkey genomic DNA segments that include regions of homology to the origin of replication of simian virus 40 (SV40). Three clearly different cloned segments 14 to 17 kilobase pairs (kb) long were isolated from a genomic library in lambda phage. We estimate that each of the three is repeated fewer than four times in the monkey genome. The SV40-like regions represent a small portion of the cloned segments, and these regions cross hybridize only weakly with one another. One of the three segments is described here in detail. Although the entire segment occurs only once or twice in the monkey genome, it contains DNA sequences (other than the SV40-like sequences) that are repeated elsewhere in the genome including in the other two cloned segments. The homology to SV40 is contained within about 300 base pairs of monkey DNA and is limited to the region around the viral replication origin. The nucleotide sequence of the SV40-like region was determined. It contains a large number of short stretches homologous to three specific noncoding domains around the SV40 origin of replication: the 27-base-pair region of dyad symmetry, the first set of (short) repeats that occur just on the late side of the origin, and, further in the late direction, the two 72-base-pair-long repeats. Although these components are grouped in the monkey DNA, as they are in SV40 DNA, their relative juxtaposition is scrambled.

Animals↗
PubMed1982

A monkey Alu sequence is flanked by 13-base pair direct repeats by an interrupted alpha-satellite DNA sequence.

A member of the Alu family, the dominant family of short interspersed repeated DNA sequences in primates, interrupts a cloned repeat unit of African green monkey alpha-satellite DNA. The Alu is immediately flanked by 13-base-pair duplications of the known sequence of the satellite at the site of insertion. These observations support the idea that Ala family members may be moveable elements.

Animals↗
PubMed1985

Transcription factor Sp1 recognizes promoter sequences from the monkey genome that are simian virus 40 promoter.

A 440-base-pair fragment of African green monkey genomic DNA shares homology with the transcriptional regulatory region of simian virus 40 (SV40) and has been reported to direct transcription in vivo. We find that two regions within this fragment bind the promoter-specific cellular transcription factor Sp1 and are protected in DNase protection ("footprinting") experiments. As in SV40, binding occurs in regions containing multiple copies of the sequence GGGCGG. These regions, when fused to the proximal, or "TATA box," element of the herpes simplex virus thymidine kinase promoter, are able to direct Sp1-dependent transcription in vitro. The finding that Sp1 is capable of productive interaction with sequences taken from a cellular promoter supports the idea that Sp1 may play a role in modulating transcription of cellular genes.

Animals↗
PubMed1985

Vaccinia virus-infected cells release a novel polypeptide functionally related to transforming and epidermal growth factors.

The recent discovery, that a vaccinia virus (VV) gene encodes a polypeptide with structural homology to transforming growth factor (TGF-alpha) and epidermal growth factor (EGF), led us to look for a virus-induced protein with the predicted biological activity. The supernatants of VV-infected cell cultures were found to contain an acid stable Mr 25,000 polypeptide that competes with EGF for binding to EGF membrane receptors. This VV-induced growth factor (VGF) like EGF and TGF-alpha is mitogenic and stimulates anchorage-independent cell growth in the presence of TGF-beta. However, VGF did not cross-react in a radioimmunoassay specific for small and large forms of TGF-alpha and exhibited minimal cross-reactivity with antisera to EGF. VGF was detectable in the culture medium within 2 hr, and maximal amounts were present 12 hr after infection. The level of VGF was proportional to the multiplicity of VV used. Inhibition of viral DNA synthesis enhanced VGF production, consistent with the hypothesis that VGF is an early gene product encoded by VV. The demonstration of a novel growth factor, released from cells infected with VV, may have important implications regarding the nature of virus-host interactions.

Animals↗
PubMed1986

Cross-reactivity to human T-lymphotropic virus type III/lymphadenopathy-associated virus and molecular cloning of simian T-cell lymphotropic virus type III from African green monkeys.

Simian T-lymphotropic retroviruses with structural, antigenic, and cytopathic features similar to the etiologic agent of human acquired immunodeficiency syndrome, human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV), have been isolated from a variety of primate species including African green monkeys (STLV-IIIAGM). This report describes nucleic acid cross-reactivity between STLV-IIIAGM and HTLV-III/LAV, molecular cloning of the STLV-IIIAGM genome, and evaluation of its structure and genetic relationship to other retroviruses. Overlapping clones from a cell line infected with virus from a single animal were found to encompass the entire STLV-IIIAGM genome and exhibit a limited degree of restriction-site variability. Specific hybridizing fragments were detected in DNA from this and other STLV-IIIAGM-infected cell lines. A fraction of viral DNA present in at least two STLV-IIIAGM lines persists as unintegrated viral DNA, a characteristic of infection with cytopathic retroviruses. Strongest cross-reactivity was detected between HTLV-III/LAV pol- and gag- genes and STLV-IIIAGM, whereas no cross-reactivity was detected between STLV-IIIAGM and molecular clones of human T-lymphotropic virus types I and II (HTLV-I and -II), visna virus, bovine leukemia virus, or feline leukemia virus.

Animals↗
PubMed1993

Rhythmic and patterned neuronal firing in visual cortex.

We present evidence from multi-electrode recordings that the stimulus driven activity in a region of monkey visual cortex displays synchronous, oscillatory behaviour with temporally changing patterns of firing. The spatial-temporal patterns are dependent on cortical layer and on visual stimulus, 'build up and die down' with a period of 70-100 msec, and cannot be factorized into separate spatial and temporal components. This finding supports neural network models which explicitly incorporate spatial-temporal structure, ruling against a purely spatial code for information processing. The new type of analysis presented here is also suitable for direct on-line interactive analysis during multi-electrode recording experiments. Further, it could be modified for use in human EEG or evoked response recordings.

Action Potentials↗
PubMed1986

Effects of chlorine dioxide on thyroid function in the African green monkey and the rat.

In a previous study from this laboratory, chlorine dioxide (ClO2) treated drinking water depressed thyroxine (T4) levels in the African green monkey. The present study again demonstrated a decrease in T4 levels in the same species after 4 wk of oral exposure. However, after 8 wk of treatment T4 levels rebounded to above pretreatment levels, coinciding with an increase in thyroid radioiodide uptake. This T4 rebound phenomenon and increased iodide uptake may be due to a compensatory endocrinological mechanism. In rats, T4 levels dropped during the 8-wk ClO2 treatment period in a dose-dependent manner, and no rebound effect was observed. Iodide uptake values in the rat were not affected. It appears that ClO2 may have an effect on thyroid function in both species.

Animals↗
PubMed2005

Class II phosphoinositide 3-kinase defines a novel signaling pathway in cell migration.

The lipid products of phosphoinositide 3-kinase (PI3K) are involved in many cellular responses such as proliferation, migration, and survival. Disregulation of PI3K-activated pathways is implicated in different diseases including cancer and diabetes. Among the three classes of PI3Ks, class I is the best characterized, whereas class II has received increasing attention only recently and the precise role of these isoforms is unclear. Similarly, the role of phosphatidylinositol-3-phosphate (PtdIns-3-P) as an intracellular second messenger is only just beginning to be appreciated. Here, we show that lysophosphatidic acid (LPA) stimulates the production of PtdIns-3-P through activation of a class II PI3K (PI3K-C2beta). Both PtdIns-3-P and PI3K-C2beta are involved in LPA-mediated cell migration. This study is the first identification of PtdIns-3-P and PI3K-C2beta as downstream effectors in LPA signaling and demonstration of an intracellular role for a class II PI3K. Defining this novel PI3K-C2beta-PtdIns-3-P signaling pathway may help clarify the process of cell migration and may shed new light on PI3K-mediated intracellular events.

Animals↗
PubMed1987

Structure of the long terminal repeat of simian lymphotropic virus type III (African green monkey) and its relatedness to that of HIV.

The simian T-lymphotropic virus type III (STLV-III[AGM]) is a retrovirus in wild African green monkeys which is serologically related to the human T-lymphotropic virus type III (HTLV-III/LAV-1/HIV) and other related human retroviruses. The long terminal repeats (LTR) contained in clones of viral DNA of (STLV-III[AGM]) were subcloned in M13 and their DNA sequence was determined and compared with that of HIV (HTLV-III[BH10]). The STLV-III(AGM) LTR is considerably larger than that of HTLV-III(BH10) (800 bp vs 634 bp) and contains a 498 bp U3 region, a 176 bp R region, and a 126 bp U5 region. These two LTR sequences share regions of significant homology. Regions of greatest homology include the 5' portion of U3, a core enhancer sequence in U3, sequences including and surrounding the TATAA promoter box in U3 and the AATAAA polyadenylation/termination signal in R, and the 3'-most region of U5. The relatively larger size of the STLV-III LTR is due to the presence in all three parts of the LTR of sequences which have no apparent homolog in the HIV LTR. Overall, the two LTRs are 47% homologous. Even greater homology (75%) is evident with a 300 bp segment including R and some of U3 from the LTR of another human retrovirus, HIV-2/LAV-2. The STLV-III LTR contains an imperfect 28 bp direct repeat in the R region which is not present in HIV. There are no obvious direct repeats in U3 homologous to the 10 bp repeat in the U3 of HTLV-III.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Cloning and sequence analysis of simian transforming growth factor-beta cDNA.

We have isolated a cDNA clone coding for the simian TGF-beta precursor from a cDNA library made from an African green monkey cell line, BSC-40. The deduced amino acid sequence of the mature simian TGF-beta shows 100% homology with that of the human TGF-beta: Strong sequence homology was found between the precursor regions of the human and simian proteins with only five amino acid changes out of 278. The simian (and murine) precursor sequence was found to code for one less amino acid residue than the human. The implications of these results with respect to the isolation of a growth inhibitor from these cells functionally related to the TGF-beta molecule are discussed.

Amino Acid Sequence↗
PubMed1990

Prostaglandins mediate the ocular hypotensive action of the angiotensin converting enzyme inhibitor MK-422 (enalaprilat) in African green monkeys.

MK-422 (enalaprilat) (0.0005-0.5%) significantly reduced intraocular pressure (IOP) in African Green monkeys. Studies utilizing unilateral instillation of MK-422 and its inactive R-isomer indicated a local site of action within the eye which is dependent upon inhibition of angiotensin converting enzyme, also known as kininase II. Tonography showed a small increase (21%) in conventional aqueous humor outflow facility which did not entirely account for the IOP lowering effect of MK-422. Pretreatment with indomethacin or pilocarpine specifically attenuated the ability of MK-422 to lower IOP suggesting that biosynthesis of prostaglandins and uveoscleral outflow pathways are important in mediating the ocular hypotension. The data indicate that MK-422 may lower IOP in monkeys by virtue of its ability to prevent the breakdown of bradykinin and thereby promote the formation of endogenous prostaglandins in the eye.

Administration, Topical↗