Not in their genes: phenotypic flexibility, behavioural traditions and cultural evolution in wild bonnet macaques.

Phenotypic flexibility, or the within-genotype, context-dependent, variation in behaviour expressed by single reproductively mature individuals during their lifetimes, often impart a selective advantage to organisms and profoundly influence their survival and reproduction. Another phenomenon apparently not under direct genetic control is behavioural inheritance whereby higher animals are able to acquire information from the behaviour of others by social learning, and, through their own modified behaviour, transmit such information between individuals and across generations. Behavioural information transfer of this nature thus represents another form of inheritance that operates in many animals in tandem with the more basic genetic system. This paper examines the impact that phenotypic flexibility, behavioural inheritance and socially transmitted cultural traditions may have in shaping the structure and dynamics of a primate society--that of the bonnet macaque (Macaca radiata), a primate species endemic to peninsular India. Three principal issues are considered: the role of phenotypic flexibility in shaping social behaviour, the occurrence of individual behavioural traits leading to the establishment of social traditions, and the appearance of cultural evolution amidst such social traditions. Although more prolonged observations are required, these initial findings suggest that phenotypic plasticity, behavioural inheritance and cultural traditions may be much more widespread among primates than have previously been assumed but may have escaped attention due to a preoccupation with genetic inheritance in zoological thinking.

Comparative immunocytochemistry of isolated rat & monkey pancreatic islet cell types.

BACKGROUND & OBJECTIVES: Data on comparative distribution of the islet cell types in the Indian bonnet monkeys and rats are not available. The aim of the present study was to compare the arrangement of the three islet cell types in the native and in isolated rat and Indian bonnet monkey islets by immunocytochemistry. METHODS: Rat islets isolated by chopped tissue collagenase digestion method and islets of monkey isolated by intraductal collagenase digestion method were immunostained by streptavidin-biotin peroxidase method. RESULTS: Immunocytochemical staining of the isolated islets in both the species revealed the presence of three different cell types: insulin secreting B cells, glucagon secreting A cells and somatostatin secreting D cells. The arrangement of islet cell types in the rats and monkeys was similar to that of the intact islets of the native pancreas but were arranged in a definite pattern. In rats the A and D cells were peripherally arranged around the centrally located B cells. In monkeys the B cells occupied the majority of the periphery while the A and D cells were found mostly in the centre. INTERPRETATION & CONCLUSION: The findings of the present study showed that the arrangement of cell types in the islets was not affected by the isolation procedure. The difference in the arrangement of islet cell types in the two species may reflect special functional adaptations.

Motor and somatosensory evoked potentials in a primate model of experimental spinal cord injury.

Motor and somatosensory evoked potentials (MEP and SSEP) were compared after experimental spinal cord injury in Bonnet monkeys (macaca radiata). The MEP and SSEP changes following graded injuries were related to clinical outcome. Eight healthy mature monkeys with a mean weight of 4.2 + 0.9 Kg were chosen for the study. Graded spinal cord injury was caused using 50, 100, 200, 300 gm-cm force by modified Allens' weight drop device. MEP and SSEP recordings were done before injury and at 0, 2, 4 and 6 hours after injury and on the 7th postoperative day. Neurological assessment was done at 24 hours and on the 7th day following injury. 50, 100, 200 gm-cm force caused partial injuries and 300 gm-cm force caused severe spinal cord injury. The predictive value of MEP and SSEP following partial injuries was 80% and 66.67% respectively. Both MEP and SSEP were 100% predictive in severe injury. MEP and SSEP monitoring can therefore be complementary to each other in predicting the neurological outcome in partial injuries to the spinal cord.

Evaluation of rabies virus neutralizing antibody titres induced by intramuscular inoculation of rabies DNA vaccine in mice and Bonnet monkeys (Macaca radiata).

A rabies DNA vaccine consisting of plasmid DNA expressing the rabies virus surface glycoprotein was injected (im) twice at two week interval to outbred swiss mice or Bonnet monkeys (Macaca radiata) and the levels of rabies virus neutralizing antibody (VNA) titres were examined over a one year period. In mice, the VNA titre was maintained above the minimum protective level (0.5 I.U./ml) up to 10 months after primary immunization, while in monkeys, the titre dropped below the protective level by 6 months. An anamnestic B cell response was seen in both mice and monkeys following the administration of a booster dose, 10 and 6 months after the primary immunization, respectively. These results indicate that im injection of rabies DNA vaccine induces VNA in nonhuman primates and mice unlike intradermal (id) immunization, which was shown to induce VNA only in mice but not in monkeys. This is the first report on the induction of VNA in nonhuman primates by im inoculation of rabies DNA vaccine.

Effect of dichloracetate on infarct size in a primate model of focal cerebral ischaemia.

Acidosis is a major contributing factor towards spread of the ischaemic focus in the brain. Drugs that increase pyruvate dehydrogenase activity could decrease the formation of lactic acidosis. The sodium salt of dichloracetic acid (DCA) has been found to be effective in reducing lactate. This study was undertaken to study the efficacy of DCA in reducing infarct size in experimental focal ischaemia in monkeys. Macaca radiata monkeys in the treatment group were given 35 mg per kilogram of dichloracetate intravenously immediately before occluding and interrupting the middle cerebral artery, and the control group was given saline as placebo under similar conditions. Mean infarct size expressed as a percentage of the size of the hemisphere in all the three brain slices was 35.38 in the control group as against l2.06 in the treated group (p=0. 0008).

Partial cloning and sequencing of a cDNA encoding bonnet monkey (Macaca radiata) oviduct specific protein.

Based on the complete nucleic acid sequence of human estrogen dependent oviductal protein and deduced amino acid sequence, potential antigenic site of the protein was identified. Two oligonucleotide primers were designed to specifically amplify the region which includes this antigenic site. With the expectation that the human, and monkey oviductins would have high nucleotide sequence homology, Bonnet monkey oviduct along with endometrium was obtained on day 5, 9, 12 and 22 of the cycle. Using RT PCR correct sized PCR product was detected in oviduct taken from day 9 and 12 of the cycle. PCR product was cloned into pBluescript KS[+] and nucleic acid sequence determined. A 96% homology to human, baboon and rhesus monkey estrogen induced glycoprotein, and a 84-88% homology to other mammalian oviductal protein was noted, thus confirming the authenticity of cDNA clone for monkey fallopian tube specific protein.

A primate model of respiratory syncytial virus infection.

To determine whether bonnet monkeys are susceptible to infection and disease due to respiratory syncytial virus (RSV), 4 juvenile bonnet monkeys (Macaca radiata) were inoculated with RSV intratracheally and sacrificed at 3, 5, 7 and 9 days post infection. RSV was cultured from pre-autopsy broncheoalveolar lavage fluid from all 4 animals with a peak titre of virus on day 9. Serum RSV neutralizing antibody was present by day 7. Animals developed tachypnoea and chest retractions by 5th day post infection and 2 animals had lobular pneumonia on chest radiography. The pathological changes were of a bronchovascular inflammation, interstitial pneumonia and alveolitis, akin to that seen in humans. These findings show that bonnet monkeys can be infected with RSV, and can develop immune response and clinical and pathological changes similar to those seen in human infants with RSV disease. Thus intractracheal RSV inoculation of juvenile bonnet monkeys appears to be a good model to study pathogenesis of RSV disease.

Effect of elevated glucose on contractile and relaxant response of aortic strips in Indian bonnet monkey (Macaca radiata radiata).

Vascular contractile response to phenylephrine and potassium chloride were examined in strips of isolated thoracic aorta from non-diabetic monkeys with and without intact endothelium exposed to glucose (5.5 mM; control) and (11 mM; high) concentration. Acetylcholine causes relaxation in isolated aortic strips with intact endothelial cells while it causes contraction in aortic strips with damaged endothelial cells. In preparations with intact and damaged endothelium, there was a significant increase in the maximal contractile response to potassium chloride when added cumulatively, on exposure to elevated glucose (11 mM) concentration as compared to control. It was also observed that relaxant response to acetylcholine and sodium nitroprusside in control (5.5 mM) and high glucose (44 mM) concentration. Endothelium-dependent relaxation to acetylcholine decreased significantly in the presence of 44 mM glucose. In preparation without endothelium, contraction caused by acetylcholine increased in the presence of glucose (44 mM). Direct smooth muscle relaxation to sodium nitroprusside remained unchanged in aortic strips with and without endothelium. Relaxation response to sodium nitroprusside decreased in strips with damaged endothelium on exposure to high glucose when compared to control glucose.

Effect of passive immunization with specific anti-FSH on tes-ticular lipids and some lipogenic enzymes of adult bonnet monkeys

The effect of anti-follicular stimulating hormone [FSH] on testicular lipid and the specific activity of testicular enzymes of the isocitrate dehydrogenase [ICDH], pyruvate/malate dehydrogenase [MDH] and malic enzyme involved in lipogenesis were studied in mature bonnet monkeys, Macaca radiata. Immunization of monkey with anti-FSH for 24 days did not produce any significant changes in the body weight, organ weight and pituitary weight. Testicular isocitrate dehydrogenase [ICDH] and malic enzyme activities were decreased significantly but MDH activity was stimulated by anti-FSH treatment. Testicular total lipid, phospholipid and cholesterol, were not altered significantly by the Anti-FSH treatment. Increased level of free cholesterol were also observed after FSH treatment. Among glyceride glycerol sub classes, triacyl glycerol showed a significant increase. Among testicular phospholipid classes, phosphatidyl inositol was markedly decreased by anti-FSH immunization. Data on serum hormonal profile, shows that there were no alteration in serum testosterone, prolactin [PRL] and luteinizing hormones [LH] but FSH was significantly decreased. The present study reveals that immunization with anti-FSH has significant effect on different class of testicular lipids and pyruvate malate enzymes cycle

Seasonal variations in Sertoli and germ cell marker enzymes in testis of rhesus and bonnet monkeys.

Variations in specific activities of the marker enzymes of Sertoli and germ cells during breeding (November-December) and non-breeding (May-June) seasons were investigated in rhesus and bonnet monkeys maintained under laboratory conditions. The marker enzymes selected for testicular cells were-Sertoli cells: beta-glucuronidase, gamma-glutamyl transpeptidase; pre-meiotic germ cells: glucose 6-phosphate dehydrogenase, malate dehydrogenase, alpha-glycerophosphate dehydrogenase; mature germ cells: LDH-X, sorbitol dehydrogenase. Results have indicated significant seasonal variation in marker enzymes only in rhesus testis. Marker enzymes of Sertoli cell increased while those of germ cell decreased significantly during non-breeding season. Marker enzymes of mature germ cells were affected much more drastically than those of the pre-meiotic germ cells.

Intravenous glucose tolerance test in Macaca radiata radiata.

A reliable method for performing sensitive intravenous glucose tolerance tests in monkeys has been standardized. This helps in assessment of beta cell function. A normal curve for glucose disposal is constructed. A high variability in insulin levels is also documented.

Xenographic transplantation of monkey pancreatic islets into rats.

Islets of Langerhans were isolated from the monkey pancreatic by collagenase digestion method. Freshly isolated monkey pancreatic islets were transplanted under the renal capsule of normal rats. Treated group of rats received Cyclosporine A injections and the control group of rats did not receive any drug. In Cyclosporine A treated rats the monkey islets were not destroyed. They maintained their normal structural integrity with occasional neutrophils surrounding the islets. In the untreated rats dense infiltration of neutrophils destroyed the islets in three days. On the seventh day dense infiltration of lymphocytes was seen. Granulomas composed of epitheloid cells and occasional multinucleated Langerhans type giant cells were seen on the fourteenth day.

Establishment of a cell line from Indian bonnet monkey (Macaca radiata) kidney and its characterization.

A cell line (MRK-90) has been established from a kidney tissue of a macaque monkey (Macaca radiata) of India. The cells are in 150th passage and have been characterized for morphology, chromosome number, isoenzyme patterns (LDH and MDH) and virus susceptibility. These studies indicate that the cells are epithelial like, heteroploid (2n = 65) and grow easily on glass surface/plastic surface without any difficulty. The cells are susceptible to a broad spectrum of viruses.

Lipid composition and membrane fluidity of monkey small intestinal brush border membrane: regional differences.

Brush border membrane vesicles (BBMV) isolated from various regions of monkey small intestine were compared for lipid composition, membrane fluidity and sodium-dependent D-glucose transport. Total phospholipid content was same in all regions whereas cholesterol content was high in duodenum and jejunum as compared to ileum resulting in higher cholesterol/phospholipid molar ratios. Regional differences in individual phospholipid subclasses and fatty acids in total lipids were also observed. Fluidity measurements showed that the membranes of duodenum and jejunum were less fluid than ileum. The change in BBMV fluidity appears to be due to alteration in cholesterol/phospholipid ratio and phospholipid composition. The sodium dependent D-glucose uptake was more in duodenum and jejunum as compared to ileum. These results suggest that there is a regional difference in the lipid composition and fluidity of BBMV in monkey small intestine which may influence their function.

Acinar cells free pure islets for transplantation from Indian bonnet monkeys.

Pancreatic islets, completely free of acinar cells were isolated from the Indian bonnet monkey Macaca radiata radiata for transplantation studies. The monkey pancreas was inflated with Hank's solution containing collagenase (5 mg/ml). After incubation for 25 min at 37 degrees C the friable pancreas was teased apart. The fragments were aspirated with a 20 ml disposable syringe (without needle) twice and ejected. After the third aspiration, the homogenate was poured over nylon mesh. Islets were separated from the filtrate by centrifugation in Ficoll gradients and then hand picked. Histological examination revealed that the islets were completely free of acinar cells. On exposure to glucose, the islets responded normally with increased insulin release. They retained their structural integrity after transplantation under the renal capsule of normal rats treated with cyclosporine. The deleterious effect of exocrine cells after transplantation will be completely eliminated by this islet preparation.

High prevalence of HTLV antibodies in wild-caught bonnet monkeys in southern India.

The prevalence of human T-lymphotropic virus (HTLV) type-1 antibodies was determined in the bonnet monkeys, living naturally, within about 30 km radius of Vellore (south India). Sera from 157 animals, collected between January 1982 and May 1993 were screened for the presence of HTLV-I infection by a particle agglutination test (PAT). When sera repeatedly reactive in PAT were subjected to indirect immunofluorescence and western blot tests, 63 (40%) were confirmed to be positive for HTLV-1 antibody. These findings are significant in the light of recent reports that HTLV infection is endemic to southern India.

Modulation of monkey small intestinal brush border membrane D-glucose transport by nonesterified fatty acids.

Brush border membranes isolated from monkey intestinal mucosa was found to contain considerable amount of nonesterified fatty acids. Incubation of brush border membranes with fatty acid free albumin selectively removed the free fatty acids more than 80% without altering the level of phospholipids or cholesterol. The sodium dependent D-glucose transport was stimulated by the albumin treatment. Kinetic study showed that albumin treatment did not alter the apparent affinity (Km) of the transporter for glucose whereas the maximal velocity (Vmax) was increased significantly. The sodium dependent D-glucose transport was inhibited by the exogenously added unsaturated fatty acids. Saturated fatty acids and methyl esters of unsaturated fatty acids showed no inhibition. Based on these results, it may be concluded that free fatty acids inhibit the sodium dependent intestinal D-glucose transport either by directly interacting with the transport protein or by abolishing the sodium gradient.

Ultrastructural specialization of intestinal epithelium over Peyer's patches in the bonnet monkey, Macaca radiata.

The follicle associated epithelium (FAE) which separates the lymphoid follicle of Peyer's patch from the gut lumen is known to have specialized cells called M cells or "microfold" cells in man and certain animals. These cells are considered to be involved in antigen uptake and transport. Our light microscopic study of the small intestine of bonnet monkeys suggested the presence of such specialised cells in FAE. We have confirmed the presence of M cells in bonnet monkey FAE having ultrastructural features very similar to those of human M cells.