Genetic load in an isolated tribal population of south India

Summary The Kota of Nilgiri Hills, Tamilnadu, are an isolated tribal population and occupy the lowest stratum in the local social hierarchy. They have developed an economic symbiotic relationship with other tribes of the Nilgiri Hills (e.g., Toda, Kurumba, Badaga), but have almost no social relationship with other communities, such as the Hindu and Muslim, communities, etc. The total population of the Kota is about 1200. Consanguineous marriages are highly favoured in this group.This paper presents data on prenatal, infant and adolescent mortality in relation to the degree of inbreeding. No perceptible difference has been found in mortality figures between consanguineous and non-consanguineous marriages. This may be due to the long history of inbreeding among the Kota. No case of visible congenital malformation has been noticed.The estimates of genetic load as revealed by inbreeding data indicate that genetic load in the Kota is low (perhaps about 1 lethal equivalent per gamete); it is also low in comparison with that in other Indian populations.     

Genetic affinities of the central Indian tribal populations

Background

The central Indian state Madhya Pradesh is often called as ‘heart of India’ and has always been an important region functioning as a trinexus belt for three major language families (Indo-European, Dravidian and Austroasiatic). There are less detailed genetic studies on the populations inhabited in this region. Therefore, this study is an attempt for extensive characterization of genetic ancestries of three tribal populations, namely; Bharia, Bhil and Sahariya, inhabiting this region using haploid and diploid DNA markers.

Methodology/Principal Findings

Mitochondrial DNA analysis showed high diversity, including some of the older sublineages of M haplogroup and prominent R lineages in all the three tribes. Y-chromosomal biallelic markers revealed high frequency of Austroasiatic-specific M95-O2a haplogroup in Bharia and Sahariya, M82-H1a in Bhil and M17-R1a in Bhil and Sahariya. The results obtained by haploid as well as diploid genetic markers revealed strong genetic affinity of Bharia (a Dravidian speaking tribe) with the Austroasiatic (Munda) group. The gene flow from Austroasiatic group is further confirmed by their Y-STRs haplotype sharing analysis, where we determined their founder haplotype from the North Munda speaking tribe, while, autosomal analysis was largely in concordant with the haploid DNA results.

Conclusions/Significance

Bhil exhibited largely Indo-European specific ancestry, while Sahariya and Bharia showed admixed genetic package of Indo-European and Austroasiatic populations. Hence, in a landscape like India, linguistic label doesn''t unequivocally follow the genetic footprints.     

Genomic structures and population histories of linguistically distinct tribal groups of India

There are various conflicting hypotheses regarding the origins of the tribal groups of India, who belong to three major language groups--Austro-Asiatic, Dravidian and Tibeto-Burman. To test some of the major hypotheses we designed a genetic study in which we sampled tribal populations belonging to all the three language groups. We used a set of autosomal DNA markers, mtDNA restriction-site polymorphisms (RSPs) and mtDNA hypervariable segment-1 (HVS-1) sequence polymorphisms in this study. Using the unlinked autosomal markers we found that there is a fair correspondence between linguistic and genomic affinities among the Indian tribal groups. We reconstructed mtDNA RSP haplotypes and found that there is extensive haplotype sharing among all tribal populations. However, there is very little sharing of mtDNA HVS-1 sequences across populations, and none across language groups. Haplogroup M is ubiquitous, and the subcluster U2i of haplogroup U occurs in a high frequency. Our analyses of haplogroup and HVS-1 sequence data provides evidence in support of the hypothesis that the Austro-Asiatic speakers are the most ancient inhabitants of India. Our data also support the earlier finding that some of the western Eurasian haplogroups found in India may have been present in India prior to the entry of Aryan speakers. However, we do not find compelling evidence to support the theory that haplogroup M was brought into India on an "out of Africa" wave of migration through a southern exit route from Ethiopia. On the contrary, our data raise the possibility that this haplogroup arose in India and was later carried to East Africa from India.     

Recent trends in nori products and markets in Asia

Since 1960s, modern techniques for nori (Porhyra) cultivation, artificial seeding of conchospores, floatingnet cultivation and freeze storage of nets, have been introduced into Japan, Korea and China. Owing to recent developments of these techniques, mechanization of processing and adaptation of fast-growing varieties of Porphyra, annual yield of nori have increased rapidly. Individual problems have, however, arisen in each country. In Japan, as the result of overproduction of nori, the farmers' profit level has, in general, decreased. As a consequence, the number of nori farmers, especially among those who would enter the industry, has declined markedly, and this is currently a serious problem. In Korea, there is a pressing need to improve the quality of nori, which is more important than increasing production. In China, the technical level of producing high quality Porphyra through cultivation and processing high quality nori is relatively undeveloped. There is thus a critical requirement to develop basic techniques in both cultivation and processing of nori in China.     

Asymmetry of finger ridge countsamong four tribal populations of Andhra Pradesh, India

The asymmetry among the four tribal populations Dulia, Kotia, Manne Dora and Manzai Mali is reported. The mean directional asymmetry (MDA) and mean absolute asymmetry (MAA) were measured for homologous fingers. The asymmetry follows a decreasing trend in radio-ulnar direction with higher mean values in thumb and index finger. The individual variation is also higher in these fingers. Neither sexual nor population differences are consistent. Jantz's Square root of A2 (another measure to assess asymmetry) for total finger ridge count and absolute finger ridge count does not indicate any significant sexual or ethnic differences. The results suggest that the underlying mechanisms influencing the level of asymmetry may be similar for all groups, and that certain dermatoglyphic areas like the thumb are more vulnerable to developmental/environmental stress, that cause asymmetry at the developmental stage.     

Insertion/deletion polymorphisms in tribal populations of southern India and their possible evolutionary implications

India has the unique distinction of having perhaps the largest diversities, both biological and cultural. The Nilgiri Hills of southern India, a home for several tribal pockets representing different genetic isolates, provides a genetic wealth to understand human evolution. We have analyzed eight widely distributed polymorphic insertion/deletion loci (AluAPO, AluACE, AluDI, AluPLAT, AluPV92, AluFXIIIB, CD4 del and mtNUC) in 250 unrelated individuals from five tribal populations (Badaga, Irula, Kota, Kurumba, and Toda). All loci were highly polymorphic except the CD4 del locus, at which the deletion allele was fixed in Kotas and Kurumbas. The levels of average heterozygosities were found to be high in all the populations. In most populations, they were also higher than those predicted by the island model of population structure. The gene diversity (GST = 8.3%) was found to be higher than that in populations of most global regions with the exception of Africa. It is clear from the present study that drift effects could have accentuated the process of genetic differentiation of the tribal populations. The possibility of an early demographic expansion of modern humans within south India also cannot be ruled out.     

Emphasizing 'Others': the emergence of Hindu nationalism in a central Indian tribal community

This article is an ethnographic account of the rise of Hindu nationalism in a central Indian 'tribal' ( adivasi ) community. It is a response to the lack of ethnographic attention within wider nationalist discourse to the kinds of social conditions and processes that have contributed to the manifestation of nationalism at the grass-roots level. It is argued that the successful spread of Hindu nationalism in specifically tribal areas is due to the instrumentalist involvement of the Rashtriya Swayamsevak Sangh (RSS), a militant Hindu nationalist organization, in local affairs. The outcome of such involvement is the promotion of the threatening 'Other' and the attachment of ethnic group loyalties to a wider nationalist agenda.     

Diversity of AM fungi in some tree species from dry land area of central Maharashtra (India)

AM symbiosis reducing damage caused by soilborne pathogen and abiotic stresses and its protection is modulated by soil and other environmental conditions. Drought stress is one of the abiotic stresses in most areas of central Maharashtra (India) and lots of tree species survive in this drought-prone area; the present investigation deals with qualitative and quantitative distribution of AM fungi in rhizosphere soil of three tree species from three localities in the dry land area of central Maharashtra, the mycorrhizal population with respect to its variation in the month of May to October and to study the physicochemical properties of rhizospheric soil.

The spore population was very high in the months of June to September in all three localities studied. The extent of colonisation by AM fungi was moderately high (70–100%). During this season there was positive correlation between AM colonisation and spore population in these months because of moderate rainfall. The species of Gigaspora and Acaulospora were dominant in Acacia arabica and Prosopis specigera rhizospheric soil, whereas the species of Glomus and Sclerocystis were dominant in association with Azadirachta indica. Thirteen dominant AM fungal species were observed in test plants. The uneven distribution of AM fungi in different localities during different seasons may be attributed to the differential physicochemical properties of soil.     

Genetic studies on Gadaba: a tribal population of Andhra Pradesh, India.

Blood samples were collected from Gadaba, a tribal population of Andhra Pradesh, South India, in order to examine the distribution of blood groups, red cell enzymes and the gammaglobulin polymorphism. Out of 20 genetic markers studied seven protein loci exhibited monomorphism. Surprisingly a case of a rare homozygous variant and twenty-one heterozygous variants at the phosphogluconate dehydrogenase locus (6-PGD), six variants at the phosphohexose isomerase locus (PHI) and a single case of phosphoglucomutase locus 1 (PGM 1) variant were observed. Further, the tribal populations of South India reveal higher frequencies of rare variants than the caste populations. However, the presence of rare variants that are phenotypically neutral may be plausibly due to their high selective value.     

Fertility and mortality differentials among selected tribal population groups of north-western and eastern India

Selection potential based on differential fertility and mortality has been computed for six tribal groups inhabiting different geo-climatic conditions, namely: Sahariya, Mina and Bhil of the State of Rajasthan, north-western India, and Munda, Santal and Lodha of the State of West Bengal, eastern India. Irrespective of the methodology, the total index of selection was found to be highest among Lodhas (0.668), followed by Sahariyas (0.524), Santals (0.462), Bhils (0.386), Mundas (0.353) and Minas (0.334). Incidentally, Lodha and Sahariya are two of the seventy-four notified primitive tribal groups of India, and these two study populations show the highest index of total selection, mainly because of a higher embryonic and postnatal mortality. The relative contribution of the fertility component to the index of total selection is higher than the corresponding mortality component in all tribal groups. The analysis of postnatal mortality components indicates that childhood mortality constitutes the bulk of postnatal mortality, suggesting that children under 5 years need better health care in these tribal groups.     

Neolithic phylogenetic continuity inferred from complete mitochondrial DNA sequences in a tribal population of Southern India

The subsequent human migrations that dispersed out of Africa, both prehistoric and historic and colonization of India by modern humans is unanimous, and phylogeny of major mitochondrial DNA haplogroups have played a key role in assessing the genetic origin of people of India. To address more such events, complete mitogenomes of 113 Melakudiya tribe of Southern India were sequenced and 46 individuals showed the presence of west Eurasian autochthonous haplogroups HV14 and U7. Phylogenetic analysis revealed two novel subclades HV14a1b and HV14a1b1 and sequences representing haplogroup U7 were included under previously described subclade U7a3a1a2* specific to India. Moreover, the present analysis on complete mtDNA reveals addition information of the spread and distribution of west Eurasian haplogroups in southern India, in tracing an unexplored genetic link between Melakudiya tribe with the people of Iranian Plateau, South Caucasus, and Central Asia. Coalescence ages of HV14 and U7a3a1a2* trees in the present study dates?~?16.1?±?4.3 and ~?13.4?±?5.6 kya respectively.     

Undernutrition among the tribal children in India: tribes of Coastal, Himalayan and Desert ecology

The purpose of the present cross-sectional investigation was to assess the nutritional condition in children of three tribal communities namely Dhodia, Kinnaura and Bhil, which belong to Coastal, Himalayan and Desert ecology, respectively, in India. A total of 989 tribal children in the age group 0-1 years through 5+ years (below 6 years) was examined. There were 306 Dhodia children (164 boys and 142 girls), 327 Kinnaura children (177 boys and 150 girls) and 356 Bhil children (168 boys and 188 girls) out of 989 subjects. Crown-heel length was measured using infantometer with the child lying supine, height with Martin's anthropometer and body weight using standard weighing machine. Body mass index (BMI) was subsequently computed. 'Z' score was undertaken to obtain comprehensive pictures of undernutrition in terms of wasting, stunting and underweight in these communities. The chi2-test test was also undertaken to compare nutritional indicators by the sexes. It was observed that maximum wasting (85.3%), stunting (86.6%) and underweight (93.3%) was recorded in Kinnaura girls, who belong to Himalayan ecology. The results revealed also that so far as wasting and stunting was concerned, the situation was worst for desert dwelling Bhil, where only 7.3% wasted and 5.6% stunted pre-school children fall in between -1 SD to < or = median as compared to 11.7% wasted and 18.3% stunted pre-school children in Dhodia and 11.3% wasted and 15.3% stunted pre-school children in Kinnaura, who fall in the same category (-1 SD to < or = median). It was important to note that the prevalence of undernutrition in terms of wasting, stunting and underweight was similar in both the sexes (chi2(2) = 1.745, p > 0.05). The findings of the present study revealed the widespread prevalence of undernutrition among the children of Dhodia, Kinnaura and Bhil tribal communities and highlight a need for an integrated approach towards improving the child health as well as the nutritional status in these areas.     

Prevalence and molecular heterogeneity of alfa+thalassemia in two tribal populations from Andhra Pradesh,India

Summary We describe here the screening of a small group of apparently healthy individuals belonging to the tribal communities of Koya Dora and Konda Reddi. A remarkably high incidence of deletion and nondeletion ⁺ thalassemia mutants has been found with allele frequencies and distributions characteristic to each tribe. We have confirmed the strict relationship between Hb S levels and the number of globin genes in double heterozygotes for the S gene and thalassemia. In this population sample we did not find either heterozygous carriers of ⁰ thalassemia (deletion of both alpha genes in cis) or individuals showing hemolytic anemia due to inactivation of three -globin genes (Hb H disease). Selection by malaria is most probably responsible for the prevalence of the various ⁺ thalassemia haplotypes among the two tribal populations of Andhra Pradesh.     

The 9-bp deletion between the mitochondrial lysine tRNA and COII genes in tribal populations of India

A 9-base-pair (bp) deletion located between the lysine tRNA (MTTK) and COII (MTCOX*2) genes in the human mitochondrial genome is a valuable marker for tracing population relationships. Previous research has shown that the 9-bp deletion is associated with two major clusters of control region sequences; one occurs in sub-Saharan Africa, while the other is associated with Asian populations and populations of Asian origin. We surveyed 898 individuals from 16 tribal populations in India and found 6 individuals with the 9-bp deletion. Sequences of the first hypervariable segment (HV1) of the mtDNA control region from these 9-bp deletion-bearing mtDNAs were compared to those previously reported from Asian and African populations. Phylogenetic analysis indicates three distinct clusters of tribal Indian 9-bp deletion mtDNA types. One cluster, found in northeast India, includes southeast Asian and Indonesian mtDNA types. The remaining two clusters appear to have unique origins in southern India. These data provide further evidence of past migrations from Asia into the northeast corner of the Indian subcontinent.     

Genetic distances among the five tribal populations of Andhra, Pradesh, South India.

In this paper, data on genetic distances among five tribal populations ae given. Among the five tribes, Koya Dora, Raj Gond and Naikpod are autochthonous populations of the Deccan plateau whereas the other two groups, Pardhan and Lambadi are migrants. Kova Doras were sampled from five distant localities. Genetic markers typed are: A1A2B0, Rho(D) blood group systems glucose-6-phosphate dehydrogenase deficiency, transferrin, haptoglobin, groupspecific component, haemoglobin, colour-vision deficiency and tastability to P. T. C. Using frequency data for the above nine genetic loci, genetic distances between the five endogamous tribes, and between the five groups of Koya Dora are calculated by adopting the statistical method of Edwards (1971). While genetic distances between Koya Dora, Raj Gond and Lambadi are minimal, the genetic distance between Pardhans and other tribal groups is maximum. Naikpods occupy an intermediate position. The closeness of Lambadi with Koya Dora and RAJ Gond can be regarded as coincidental. Interestingly, the differences in the genetic distance values between five Koya Dora groups are as great as the differences between the five endogamous tribal populations tested for the same loci. Genetic affinities of these tribal populations are discussed in relation to their ethnic origin migration and geographical isolation.