Gc and transferrin isoelectrofocusing subtypes among Brazilian Indians

A total of 397 persons living in six villages of three Brazilian Indian tribes were studied in relation to the Gc subtypes. The corresponding gene frequencies are more similar between the Gorotire and Caingang than between the Gorotire and the Krahó, despite the considerable geographical distance that separates the villages of these two first tribes and their lignuistic differentiation. An uncommon variant pattern (1C7) was observed in eight Gorotire Indians; it had been described for the first time in a Tibetan sample, furnishing additional evidence on the Asiatic origin of these Indians. The distinct Gc subtype frequencies observed in our main ethnic groups provide an important new tool for anthropological analyses. Tf subtypes were studied among the Caingang only. The frequencies of Tf^C1 and Tf^C2 are similar to those obtained by other researchers in Hessen, Germany.     

The genetic structure of a tribal population, the Yanomama indians. VII. Anthropometric differences among Yanomama villages

Anthropometric data on 12 variables in 19 villages of the Yanomama Indians demonstrate significant heterogeneity in physique among villages of this tribe. Mahalanobis' distances (D²) calculated from the data lead to the tentative conclusion of a general correspondence between anthropometric and geographic distances separating villages. The mean stature of the Yanomama is smaller than that of most other South American tribes which have been measured, and the Yanomama are genetically distinct from the other small Indians as shown by genetic distances based on allele frequencies for a variety of genetic markers. Since some subjects were measured more than once by the same and by different observers, it was possible to calculate approximate estimates of variance within and between observers. Univariate analysis indicates that face height and nose height are especially susceptible to systematic differences in technique between observers. The variances obtained in this field study compare favorably with those of some classical laboratory studies described in the literature. It was found that measurement error nevertheless probably makes a substantial contribution to anthropometric distance between villages. The median error variance as a fraction of that of Herskovits ('30) is 0.62 for the seven measurements in common with this study. The median value of the error variance for the 12 variables in this study is between 16% and 17% of the total variance.     

Electrophoretic and isoelectric focusing studies in Brazilian Indians: data on four systems

Three-hundred ninety-nine individuals living in seven populations of two Brazilian Indian tribes (Macushi and I?ana River Indians) were tested for the phosphoglucomutase 1 (PGM1), properdin factor B (BF), haptoglobin (HP), and alpha-1-antitrypsin (PI) systems. We observed significant internal heterogeneity in the two tribes for the PGM1 alleles and in the Macushi for the HP markers. Frequencies in three of the four systems (the exception being BF) also show clear differences in the Macushi and I?ana River Indians. Compared with other ethnic groups, South American Indians generally present high frequencies of PGM1*1B, BF*S, HP*1S, and PI*M3. On the other hand, PGM1*1A, PI*M1, and PI*M2 are reduced, and HP*1F is absent or rare. This is the first report about HP subtypes among American Indians.     

Finger dermatoglyphics of the Peruvian Cashinahua

The Peruvian Cashinahua are an isolate of unmixed American Indians living in four villages in the Southeastern part of the country. Finger dermatoglyphic data were collected from the three most closely grouped villages in the summer of 1966. The relatively low proportion of whorls and high proportion of arches, and the low values of pattern intensity (10.75) and total ridge count (89.14) contrasts markedly with other American Indian groups in general, and with Amazon Basin groups in particular. The distinctive finger print patterns may be explained by factors such as genetic drift and inbreeding, which can alter gene and phenotype frequencies in small populations.     

Intra and intertribal genetic variation within a linguistic group: The Ge-speaking Indians of Brazil

A total of 562 individuals living in four villages of two Brazilian Indian tribes (Cayapo and Krahó) was studied in relation to blood groups ABO, MNSs, P, Rh, Lewis, Duffy, Kidd and Diego; haptoglobin, Gc, acid phosphatase and phosphoglucomutase types. These results were compared with those obtained previously among the Xavante, and the inhabitants of three other Cayapo villages, all of whom speak Ge languages; the ranges in gene frequencies observed in a representative series of South American Indians from all over the continent were also compiled. The Ge Indians are characterized by low frequencies ofR^z, medium frequencies ofR¹,R², R⁰, orr,Jk^a andPGM¹₁, and high frequencies ofGc² andACP^A when compared with other South American tribes. Genetic distance analyses based on six loci indicate that the intratribal variability observed among Cayapo is of the same order of magnitude as those obtained among the Xavante and Krahó, being much less pronounced than those observed among the Yanomama and Makiritare. The intertribal differences within this linguistic group are much less pronounced than those encountered among tribes that speak more differentiated languages.     

Gene and gene-product variation in the apolipoprotein A-I/C-III/A-IV cluster in the Dogrib Indians of the Northwest Territories.

The Dogrib, an Amerindian tribe residing in the Northwest Territories of Canada, were typed for DNA and protein polymorphism at the apolipoprotein A-I/C-III/A-IV gene cluster. Variation was seen at three previously described RFLPs detected with the enzymes SstI, PstI, and XmnI, though frequencies of these polymorphisms differ significantly from those reported in other populations. They exhibit no variation at two previously reported PvuII sites. No variation was seen in the APO A-I or APO A-IV gene products, with the Dogrib showing the most common isoelectric-focusing/immunoblot patterns of other world populations. Haplotype frequencies computed from inferred haplotypes and by maximum likelihood estimation did not differ significantly. The extent of nonrandom association of these sites is highly significant (P less than .00001), though pairwise analysis shows significance between the SstI and XmnI sites only. Levels of fasting triglyceride and fasting total cholesterol were determined for each individual. Analysis of covariance shows that fasting triglyceride levels in women vary significantly with the XmnI genotype. These results suggest that genetic variation at the APO A-I/C-III/A-IV gene cluster may be a useful tool for the study of quantitative lipoprotein variation in the Dogrib.     

Characteristics of polymorphism at a VNTR locus 3' to the apolipoprotein B gene in five human populations.

We have analyzed the allele frequency distribution at the hypervariable locus 3' to the apolipoprotein B gene (ApoB 3' VNTR) in five well-defined human populations (Kacharis of northeast India, New Guinea Highlanders of Papua New Guinea, Dogrib Indians of Canada, Pehuenche Indians of Chile, and a relatively homogeneous Caucasian population of northern German extraction) by using the PCR technique. A total of 12 segregating alleles were detected in the pooled sample of 319 individuals. A fairly consistent bimodal pattern of allele frequency distribution, apparent in most of these geographically and genetically diverse populations, suggests that the ApoB 3' VNTR polymorphism predates the geographic dispersal of ancestral human populations. In spite of the observed high degree of polymorphism at this locus (expected heterozygosity levels 55%-78%), the genotype distributions in all populations (irrespective of their tribal or cosmopolitan nature) conform to their respective Hardy-Weinberg predictions. Furthermore, analysis of the congruence between expected heterozygosity and the observed number of alleles reveals that, in general, the allele frequency distributions at this locus are in agreement with the predictions of the classical mutation-drift models. The data also show that alleles that are shared by all populations have the highest average frequency within populations. These findings demonstrate the potential utility of highly informative hypervariable loci such as the ApoB 3' VNTR locus in population genetic research, as well as in forensic medicine and determination of biological relatedness of individuals.     

The Genetic Structure of a Tribal Population, the Yanomama Indians. VI. Analysis by F-Statistics (Including a Comparison with the Makiritare and Xavante

The infra-structure of three relatively undisturbed tribes of American Indians (Yanomama, Makiritare, Xavante) has been investigated by means of the F-statistics of Wright, using 8, 9 and 6 codominant systems respectively. The data for the first two mentioned tribes are much more extensive (37 and 7 villages) than for the third (3 villages), and much of the argument is based on the first two. An additive model partitioning F(IS) into an average effect (F(A)) and deviations due to deme size, systems effects, village effects, and random error has been employed. The Cannings-Edwards formulation suggests that the small size of the demes alone would result in an F(IS) of -0.008 for the Yanomama and -0.007 for the Makiritare. There is no evidence for significant village or systems effects. Despite considerable scatter, F(A) values are not significantly heterogeneous and tend to be negative (-0.012 to -0.023). On the basis of a computer simulation model, it appears that there is an excess of consanguineous marriage over random expectation, i.e. the negative F(A) values are probably not due to avoidance of close inbreeding in a subdivided population in which demes are small. Aspects of population structure which could contribute to negative F(A) values are identified. These include unequal gene frequencies in the sexes and occasional marked differential fertility. It is at this point unnecessary to introduce overdominance as a cause of the negative F(A) values, since a computer simulation program which does not incorporate selection satisfactorily reproduces the observed F(IS) values. If population breeding structure alone can result in negative F(IS) values, then this may constitute a mechanism for retarding random fixation.-Mean F(ST) values are 0.063 for the Yanomama and 0.036 for the Makiritare. While truly comparable data are lacking, it seems likely these will be found to be relatively high values for human populations. F(IT) values have been calculated by both direct and indirect approaches. The direct approach yields a value of 0.045 for the Yanomama and -0.009 for the Makiritare; the respective indirect values are 0.085 and 0.017. The primary identifiable reason for this difference between tribes is the greater genetic heterogeneity among Yanomama villages. The assumptions underlying the indirect approach to the calculation of F(IT) do not appear to be met in these populations.     

Genetic demography of the amazonian Ticuna Indians

The Ticuna Indians of Brazil are now a largely acculturated and integrated tribe, situated for the most part in villages along the Solimões river. Demographic information collected in eight of their villages is reported here. For five of them detailed data concerning migration, fertility and mortality were obtained. They are characterized by a relatively large mobility, high fertility (mean number of livebirths per female of age 40 or more: seven), low (2·5%) frequency of sterile couples, and relatively low mortality for groups living at this cultural stage (25% of deaths before the age of reproduction). This low mortality, and a relatively small variance in the number of live-born children in completed families, lead to the lowest index of opportunity for selection obtained thus far in populations of South American Indians (0·54).     

Reconstructing history: the Amazonian Mura Indians

We studied demographic characteristics of two Mura Indian villages. Two-hundred six inhabitants of these villages and another population were tested in relation to 30 blood and 4 saliva genetic systems. These groups exhibit high mobility and exogamy rates and high fertility but relatively low mortality and variance in number of children per woman. Hb J Oxford and albumin Maku were observed, and they show high prevalences of GPT*1 and RH*R1 but low of HP*1 compared to other South American Indians. Four electrophoretic saliva systems are reported here for the first time in a predominantly Amerindian group. The amount of polymorphism was more limited than that found in Caucasian, black, and Oriental populations. The Mura are still predominantly Indian (82%) but have African (11%) and Caucasoid (7%) admixture. Using these values, the putative ancestral Mura gene frequencies were assessed. Problems related to quantitative estimations of admixture and the factors that influence the process are discussed.     

The Brazilian focus of onchocerciasis: new observations in the areas of the Mucajaí and Catrimani rivers, Territory of Roraima

A recent survey for onchocerciasis conducted among the Yanomami Indians living on the middle reaches of the Mucajaí and Catrimani Rivers (Territory of Roraima) has failed to show any alteration in the local pattern of the disease. In fact, after a decade from the first surveys in these areas located at the periphery of the Yanomami focus, the prevalence and the intensity of infection have not experienced a significant change. Considering only the residents in the villages inside the surveyed areas, the prevalence varied from zero in the neighbourhood of the Catrimani mission to 3.1 per cent near the Mucajaí mission. Had there been a competent vector of Onchocerca volvulus in the region higher rates might be expected due to the Yanomami custom of periodic visits among the groups of the tribe. In some of these visits, numbers of highly infected Indians from the central and mountainous part of the Yanomami territory--where more than 90 per cent of the adults have onchocerciasis--come to the villages in the lowland area, attracted by the facilities offered by the mission posts. As the visitors stay in the host villages for several days or weeks, the residents could become exposed to the disease. Simulium oyapockense s.1., a man-biting species of black fly, widely distributed in Northern Brazil, is the only possible vector of O. volvulus in the investigated areas, on the grounds of its local abundance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mansonella ozzardi in the Federal Territory of Roraima, Brazil. Distribution and finding of a new vector in the area of Surumu River

A survey conducted among the Makuxi Indians from 15 settlements in the northeastern part of the Territory of Roraima, Brazil, revealed the occurrence of Mansonella ozzardi in 3,2% (21/652) of the persons examined. The absence of demonstrable infection--with one exception--in persons under 15 years of age, and the low microfilaria density in adults suggest that mansonelliasis has been acquired by the Makuxi Indians outside their villages. As many Indians from the region pan gold on the Upper Maú (Ireng) river--where black flies occur in great quantity--the mining camps are probably the sites of transmission. Experimental infection with M. ozzardi of Simulium oyapockense s.l. (or Simulium roraimense) showed that this species, at the least in the Surumu river area, is capable of supporting the full development of the microfilariae. Although S. oyapockense has a wide distribution in the extreme north of Brazil, it does not appear to be an efficient vector, since only 20,6% (19/92) of the specimens collected after a blood meal on a naturally infected Indian contained larval stages of M. ozzardi (with an average of 1-2 larvae per fly). The high prevalence rate of infection found, in a previous survey, among the Sanumá and Mayongong, two Indian groups living at the Auaris river area, on the other side of the Territory of Roraima, indicates that a more competent intermediate host should exist in that region.     

Taste sensitivity to phenylthiocarbamide (PTC) and endemic goiter in the Indian natives of Peruvian highlands

In 263 Peruvian Indians, natives and residents of Andean villages in the Department of Pasco, where goiter is endemic, very low frequencies of PTC non-tasters were found in agreement with other data on South America Indians. The data suggest that in this population the risk of developing goiter either is not associated with the tasting non-tasting dimorphism, or is greater in the taster class.     

Population Genetic Characteristics of the D1S80 locus in seven human populations

We have analyzed the allele frequency distribution at the highly polymorphic variable number of tandem repeat (VNTR) locus D1S80 (pMCT118) in seven ethnic populations (namely, New Guinea Highlanders of Papua New Guinea, Dogrib Indians of Canada, Pehuenche Indians of Chile, American and Western Samoans, Kacharis of Northeast India, and German Caucasians) using the polymerase chain reaction (PCR) technique. In the pooled sample of 443 unrelated individuals 20 segregating alleles were detected. A trimodal pattern of allelic distribution is present in the majority of populations and is indicative of the evolutionary antiquity of the polymorphism at this locus. In spite of the observed high degree of polymorphism (expected heterozygosity 56%–86%), with a single exception — the marginally significant P value (0.04) of the exact test in American Samoans — the genotype distributions in all populations conform to their respective Hardy-Weinberg expectations. Summary statistics indicate that, in general, the allele frequency distribution at this locus may be approximated by the infinite allele model. The data also demonstrate that alleles that are shared by all populations have the highest average frequency within populations. Furthermore, the kinship bioassay analysis demonstrates that the extensive variation observed at the D1S80 locus is at the interindividual within population level, which dwarfs any interpopulation allele frequency variation, consistent with the population dynamics of hypervariable polymorphisms. These characteristics of the D1S80 locus make it a very useful marker for population genetic research, genetic linkage studies, forensic identification of individuals, and for determination of biological relatedness of individuals.     

Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil

Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil, was studied from September 1993 to October 1994 to assess the current levels of resource exploitation. Hunting effort, harvesting yields and species composition of the hunt were recorded daily in five villages varying in number of people, location and age of the settlement. The Waimiri Atroari harvested a total of 3004 individuals of 41 species in one year. Lowland tapir (Tapirus terrestris), white-lipped peccary (Tayassu pecari), collared peccary (T. tajacu) and spider monkey (Ateles paniscus) represented 87% of the total yearly game weight. Sex ratios of spider monkeys killed were heavily biased towards females indicating a stronger hunting pressure on those individuals. Harvesting yields was proportional to hunting efforts indicating no evident game depletion in the study period. However, capture per unit of effort was significantly different among villages. Differences in total game mass harvested may be explained by local resource depletion associated with age and size of the settlement. However, this relationship is confounded by the capacity of some villages to exploit distant hunting sites. Data obtained in one village showed that harvest rates were higher in hunting sites located far from settlement indicating game depletion in hunting sites surrounding the village.     

Comparison of basal glutathione S-transferase activities and of the influence of phenobarbital, butylated hydroxy-anisole or 5,5'-diphenylhydantoin on enzyme activity in male rodents

1. Hepatic cytosolic glutathione S-transferase (GST) activities, toward five substrates, were shown to vary markedly among three laboratory rodent species. 2. Basal GST activities for 1-chloro-2,4-dinitrobenzene (hamster greater than mouse greater than rat), 1,2-dichloro-4-nitrobenzene (mouse greater than rat greater than hamster), p-nitrobenzyl chloride (rat = mouse = hamster), bromosulfophthalein (rat greater than mouse greater than hamster) and 1,2-epoxy-3-(p-nitrophenoxy)propane (mouse greater than rat = hamster) differed with respect to magnitude and distribution among species. 3. GST substrate activities in response to phenobarbital, butylated hydroxy-anisole or 5,5'-diphenylhydantoin treatment were increased more often in mouse and rat as compared to the hamster. 4. These results suggest that basal GST activity, as well as inducibility, differ among rodent species. Since GST are involved in detoxication processes, differences in GST properties may underlie variability in species sensitivity to toxicants.     

A comparative study of the substrate and inhibitor specificity of the glutathione transferase from the spring grain aphid (Schizaphis gramina Rond.) and from rat liver]

Kinetic parameters of 9 substrates interaction with glutathione transferase (GST) from spring grain aphid and rat were studied. The most significant difference in Vmax values was noticed for 4-nitropyridine-N-oxide (6 times higher for aphid) and ethacrynic acid (7 times higher for rat). Km values were practically in all cases higher for aphid GST as compared to rat GST. New class of effectors of GST suggested by us, that is azimines (2 series), was used for the inhibitor analysis. GST interaction with these inhibitors was appreciated by three types of activity: nucleophilic replacement, thiolysis and N-deoxygenation. It has been shown that the degree of GST inhibition depended considerably both on the GST source and the substrate used. New high-effective inhibitors of GST were found among azimines and their higher specificity to rat GST as compared to aphid GST was demonstrated especially in thiolysis reaction.     

Genetic structure of a tribal population, the Yanomama Indians. XIII. Dental microdifferentiation.

Data are presented on the frequency of the following eight dental traits in 635 Yanomama and 65 Makiritare Indians: upper central incisor rotation or winging, shoveling of maxillary incisors, maxillary molar hypocone reduction, Carabelli's trait, mandibular molar cusp number, mandibular molar cusp pattern rotation of second lower premolar, and pattern of second lower premolar cusps. Yanomama dentition is unusual in the high frequency of six cusps on the mandibular molars. There is marked dental microdifferentiation between villages; significant agreement was observed between a matrix of pairwise "dental distances" based on six morphological traits and corresponding matrices based on 11 genetic systems and on geographic location.     

Comparative studies on the isoenzymes of glutathione S-transferase of rat brain and other tissues

Six forms of glutathione S-transferase (GST) designated as GST 9.3, GST 7.5, GST 6.6, GST 6.1, GST 5.7 and GST 4.9 have been purified to homogeneity from rat brain. All GST isoenzymes of rat brain are apparent homodimers of one of the three type subunits, Ya, Yb, or Yc. More than 60% of total GST activity of rat brain GST activity is associated with the isoenzymes containing only the Yb type of subunits. In these respects brain GST isoenzymes differ from those of lung and liver. The Ya, Yb, and Yc type subunits of brain GST are immunologically similar to the corresponding subunits of liver and lung GST. The isoelectric points and kinetic properties of the Yb type subunit dimers in brain are strikingly different from those of the Yb type dimers present among liver GST isoenzymes indicating subtle differences between these subunits of brain and liver.