Measuring opportunity for natural selection: Adaptation among two linguistically cognate tribes inhabiting two eco-situations of North-East India

BACKGROUND:

Numerous literature on the migration of Mishings point out to the fact that the Mishing and the Minyong are two culturally and linguistically cognate tribes that co-existed in the same ecology in the hills of Arunachal Pradesh. The Mishing tribe after migration, now inhabits flood-prone areas of Brahmaputra valley of Assam.

AIM:

The study aims to measure the adaptation process of these two cognate tribes inhabiting two different ecologies at present: Hills and plains by calculating the index of selection intensity by Crow’s and Johnston and Kensinger’s formulae.

MATERIALS AND METHODS:

The reproductive histories of 77 Mishing mothers of completed fertility inhabiting a flood affected village of Assam and 74 Minyong mothers inhabiting a hilly village of Arunachal Pradesh are selected.

RESULTS AND DISCUSSION:

The Minyongs show higher average fertility than the Mishings. The proportion of embryonic death is higher, and child death is lower among the Mishings (0.1661; 0.1623) than the Minyongs (0.1319; 0.2238). The index of selection due to mortality component is contributing more toward the total index of selection in both the tribes.

CONCLUSION:

The contribution of mortality component is sizeable to the total selection like many other tribes of North-East India. Higher proportion of embryonic deaths among the Mishings infers that the causes are mostly biological whereas, the higher proportion of child deaths among the Minyongs infers that the causes are mostly socio-cultural.     

Dopamine receptor D4 exon 3 variable number of tandem repeat polymorphism: Distribution in eastern Indian population

BACKGROUND:

A 48bp variable number of tandem repeat (VNTR), in the dopamine receptor D4 (DRD4), has been extensively studied in association with a variety of traits and neuropsychiatric disorders in different ethnic groups; the VNTR has been found to affect receptor binding.

AIMS:

This investigation, for the first time, compared distribution of DRD4 VNTR in different Indian populations from the eastern part of the country, belonging to Indo-Caucasoid and Indo-Mongoloid ethnicity.

MATERIALS AND METHODS:

852 individuals were recruited and divided into six population groups; Brahmin, Kayastha, Scheduled Caste, Mahishya, Muslim and Manipuri (Meitei). Allele and genotype frequencies were compared among groups as well as with data available for south-western Indian population.

RESULTS:

A total of six alleles (2-7-repeats) were observed, of which the 4-repeat (4R) was most frequent. Gross genetic dissimilarities were noticed between the Indo-Caucasoid and Indo-Mongoloid ethnic groups. Muslim group lacked 5R and 7R, while Manipuri group exhibited a very high frequency of 2R. Populations from eastern India revealed lower 7R frequencies as compared to the south-western populations.

CONCLUSIONS:

The DRD4 VNTR has been reported to play important role in cognition and alleles with higher repeats have been found to be associated with novelty seeking and personality traits. The present comparative analysis of different eastern Indian population would be helpful in extending our knowledge on this particular DRD4 variant. It will also be useful in understanding the behavioural differences between populations in the light of their genetic make up.     

Genetic analysis of OCT1 gene polymorphisms in an Indian population

BACKGROUND:

Genetic variants of the organic cation transporter (OCT1) gene could influence interindividual variation in clinical response to metformin therapy. The genetic basis for the single-nucleotide polymorphism (SNP) of OCT1 gene has been established in other populations, but it remains to be elucidated in the Indian population. This study is focused on OCT1 gene variants rs2282143 (P341L, 1022C>T), rs628031 (M408V, 1222A>G) and rs622342 (1386C>A) frequency distributions in the South Indian Tamilian population.

MATERIALS AND METHODS:

A total of 112 unrelated healthy subjects of South Indian Tamilian origin, aged 18–60 years, of either sex were recruited for the study. Genotyping was determined using the quantitative real time-polymerase chain reaction and polymerase chain reaction followed by restriction fragment length polymorphism methods.

RESULTS:

Allele frequencies of rs2282143, rs628031and rs622342 polymorphisms were 8.9%, 80.3% and 24.5%, respectively. Interethnic differences in the genotype and allele frequencies of OCT1 gene polymorphism were observed when compared with other major populations. The SNPs rs2282143, T allele and rs628031, G allele were more common in Asians (5.5–16.8% and 76.2–81%) and African Americans (8.2% and 73.5%) than in Caucasians (0–2% and 57.4–60%).

CONCLUSION:

This is the first time the frequency of OCT1 gene polymorphism was determined in the Indian population, and is similar to the frequencies observed in African-Americans and other Asian populations but different from those in Caucasians. The data observed in this study would justify further pharmacogenetic studies to potentially evaluate the role of OCT1 gene polymorphism in the therapeutic efficacy of metformin.     

Haptoglobin polymorphism among the tribal groups of southern Gujarat

BACKGROUND:

Gujarat is located at the western most point of the Indian subcontinent. Valsad and Surat districts are part of the ‘tribal belt’of Gujarat and constitute 29.1% of total tribal population of Gujarat. These tribal populations are a rich source of gaining insights in the patterns of genetic diversity and genetico-environmental disorders against the back drop of their ecological, historical and ethnographic aspects.

AIM:

The objectives were to find out a) the genetic diversity among the tribes of Gujarat with reference to haptoglobin (Hp) locus b) the relationship between Hp polymorphism and sickle cell anemia/trait.

MATERIALS AND METHODS:

431 individuals belonging to eight tribal groups were studied for Hp polymorphism using polyacrylamide disc gel electrophoresis (PAGE). Hb*S was screened by dithionate tube turbididy (DTT) test and confirmed using cellulose acetate membrane electrophoresis (CAME).

STATISTICAL ANALYSIS:

Allele frequency was calculated by direct gene counting method. Average heterozygosity and gene diversity were computed using software DISPAN. Analysis of molecular variance (AMOVA) was estimated using software ARLEQUIN version 3.1.

RESULTS AND CONCLUSIONS:

Pattern of allele frequency distribution showed preponderance of Hp² allele in all the eight tribal groups, which is in accordance with its frequency in different populations of Indian subcontinent. Total average heterozygosity (H_T) was found to be low (0.160) but the level of genetic differentiation (G_ST) was found to be moderately high (5.6%). AMOVA analysis indicated least among group variance between west and south Indian populations (-0.04%) indicating the affinities of the tribes of Gujarat with that of Dravidian speaking groups. Analysis of Hp phenotypes among sickle cell anemia/ trait individuals revealed a high frequency of Hp 0-0 phenotype (92.7%) among SS individuals as opposed to only 9.7% among AS individuals, reaffirming the selective advantage of HbAS state in relation to hemolytic disorders.     

Association of microsatellite instability and chronic obstructive pulmonary disorder in isocyanate-Exposed population of Bhopal

CONTEXT:

Survivors of the Bhopal gas disaster still suffer from various respiratory ailments. We examined the effects of exposures among a cross-section of current residents suffering from COPD by ISSR-PCR.

AIMS:

Molecular screening of the gas-affected population of Bhopal with COPD for microsatellite instability due to exposure of MIC.

SETTINGS AND DESIGN:

The isocyanate-exposed population of Bhopal city suffering from chronic obstructive pulmonary disorder.

MATERIALS AND METHODS:

Inter-(SSR) analysis was used to characterize microsatellite instability in 52 MIC victims of Bhopal, suffering from COPD using (CA)₈RG and (CA)₈R[Y-Q] primer.

STATISTICAL ANALYSIS USED:

Association analyses were performed using regression analysis.

RESULTS:

The study on the MIC-affected population in Bhopal showed weak association between microsatellite instability and age (r = + 0.37); exposure distance from site (r = −0.44); and smoking status(r = + 0.12); while regression analysis of the above parameters displayed supporting evidence.

CONCLUSIONS:

The high prevalence of smoking coupled with aging and poor living habits threatens, to further increase COPD incidences among this population, highlighting the need for enhanced screening efforts.     

Inbreeding as a cause for deafness: Dadhkai study

BACKGROUND:

We report on the higher prevalence of deaf-mutes from a village in Jammu and Kashmir State of India.

MATERIALS AND METHODS:

A cross-sectional study among 79 deaf mutes using pedigree analysis, audiometry, imaging and molecular analysis.

RESULTS:

A high rate of hereditary deafness with 79 individuals diagnosed to be suffering from non-syndrome deafness in a total population of 2452 individuals residing in the village.

INTERPRETATION:

Flourishing of intermarriages led to a population with high prevalence of deafness     

Frequency of fokI and taqI polymorphism of vitamin D receptor gene in Indian population and its association with 25-hydroxyvitamin D levels

BACKGROUND:

The VDR protein is at the centre of the vitamin D endocrine system, a complex physiological system with substantial feedback regulatory mechanisms involved in maintaining serum calcium and 1, 25 dihydroxy vitamin D3. Variations in VDR gene are shown to have implications in several diseases and have also been implicated as an important genetic factor affecting bone mass.

AIM:

To determine the frequency of Fok I and Taq I variants in healthy Indian individuals and its association with 25-OH-Vitamin D levels.

SETTINGS AND DESIGN:

Blood samples were collected from 143 unrelated normal individuals (Male-84 and Female-59) and their genotypes determined.

MATERIALS AND METHODS:

After amplification by polymerase chain reaction, each polymorphism was genotyped by restriction fragment length polymorphism. For 100 normal healthy individuals 25-hydroxyvitamin D estimation was done using DiaSorin kit method.

STATISTICAL ANALYSIS:

Graph pad software was used to calculate the P values from the Chi-square.

RESULTS:

Out of 143 samples analyzed for FokI and TaqI polymorphisms the following genotypic frequency was obtained FF 59%, Ff 36%, ff 5% and TT 49%, Tt 43%, tt 8% respectively.

CONCLUSIONS:

Results indicate that the distribution of the polymorphic loci Fok I and Taq I vary considerably not only in different populations, but also within India. Furthermore, when the genotypes were analyzed with respect to 25-OH-Vitamin D levels, a significant association was seen for the Taq 1 SNP but not with the Fok I.     

Mutational identification of fibroblast growth factor receptor 1 and fibroblast growth factor receptor 2 genes in craniosynostosis in Indian population

OBJECTIVE:

The Objective of this study was to identify the association of mutation of fibroblast growth factor receptor 1 (FGFR1), FGFR2 genes with syndromic as well as non-syndromic craniosynostosis in Indian population.

MATERIALS AND METHODS:

Retrospective analysis of our records from January 2008 to December 2012 was done. A total of 41 cases satisfying the inclusion criteria and 51 controls were taken for the study. A total volume of 3 ml blood from the patient as well as parents was taken. Deoxyribonucleic acid extracted using phenol chloroform extraction method followed by polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS:

There were 33 (80.4%) non-syndromic cases of craniosynostosis while 8 (19.5%) were syndromic. Out of these 8 syndromic cases, 4 were Apert syndrome, 3 were Crouzon syndrome and 1 Pfeiffer syndrome. Phenotypically the most common non-syndromic craniosynostosis was scaphocephaly (19, 57.7%) followed by plagiocephaly in (14, 42.3%). FGFR1 mutation (Pro252Arg) was seen in 1 (2.4%) case of non-syndromic craniosynostosis while no association was noted either with FGFR1 or with FGFR2 mutation in syndromic cases. None of the control group showed any mutation.

CONCLUSION:

Our study proposed that FGFR1, FGFR2 mutation, which confers predisposition to craniosynostosis does not exist in Indian population when compared to the western world.     

Identification of a rare blood group, "Bombay (Oh) phenotype," in Bhuyan tribe of Northwestern Orissa, India

BACKGROUND:

Blood group serology plays a vital role in transfusion medicine. The Bombay (Oh) phenotype is characterized by the absence of A, B, and H antigens on red cells and occurs rarely, especially in tribal populations of India.

AIMS AND OBJECTIVES:

This is a field-based random population study in the Bhuyan tribal community. The study reports three cases of the rare Bombay (Oh) phenotype for the first time in the Bhuyan tribe of Sundargarh district in North-Western Orissa.

MATERIALS AND METHODS:

Taking informed consent, red blood cells of 836 Bhuyan subjects were tested with three antisera, i.e., anti-A, anti-B, and anti-H (lectin) for forward reaction. Agglutinations of plasma with A, B, and O (H) red cells (reverse reaction) were also tested for the presence or absence of antibodies in the serum. Specialized tests like absorption-elution, titration of naturally occurring antibodies at different temperatures, inhibition of anti-H by O saliva secretor, and determination of secretor status were performed.

RESULTS:

Three cases of a rare blood group, Bombay (Oh) phenotype, (2 out of 244 Khandayat Bhuyan and 1 out of 379 Paudi Bhuyan from Hemgiri and Lahunipara blocks, respectively) in the Bhuyan tribe of Sundargarh district in North-Western Orissa were detected, giving an incidence of 1 in 122 in Khandayat Bhuyan and 1 in 379 in Paudi Bhuyan, with an average of 1 in 278 among the Bhuyan tribal population. This incidence is high in comparison to earlier studies reported from India.

CONCLUSIONS:

The practice of tribal and territorial endogamy in a smaller effective populations (for example, there are only 3,521 individuals in Paudi Bhuyan) results in smaller marital distance and inbreeding, leading to increased homozygous expression of rare recessive genetic characters like the Bombay (Oh) phenotype. This study further testifies that the incidence is higher in those states of India where the consanguinity is a common practice.     

Missense mutation G296S in GATA4 is not responsible for cardiac septal defects

BACKGROUND:

The most common type of congenital heart disease is the cardiac septal defects, which has reported to be caused by a missense mutation (G296S) in exon 3 of the GATA4 gene.

AIMS:

The present study was undertaken to find out whether GATA4 gene is the prime cause of the septal defects in Mysore population.

MATERIALS AND METHODS:

GATA4 gene analyses were undertaken on 21 confirmed CHD cases by PCR and DNA sequencing.

RESULTS AND CONCLUSION:

Analysis of this particular mutation in 21 septal defect patients revealed that none of the patients had the mutation, indicating that this mutation is population specific or septal defect in Mysore population is caused due to mutations in other regions of the GATA4 gene.     

Subtelomeric chromosomal rearrangements in a large cohort of unexplained intellectually disabled individuals in Indonesia: A clinical and molecular study

CONTEXT:

Unbalanced subtelomeric chromosomal rearrangements are often associated with intellectual disability (ID) and malformation syndromes. The prevalence of such rearrangements has been reported to be 5-9% in ID populations.

AIMS:

To study the prevalence of subtelomeric rearrangements in the Indonesian ID population.

MATERIALS AND METHODS:

We tested 436 subjects with unexplained ID using multiplex ligation dependent probe amplification (MLPA) using the specific designed sets of probes to detect human subtelomeric chromosomal imbalances (SALSA P070 and P036D). If necessary, abnormal findings were confirmed by other MLPA probe kits, fluorescent in situ hybridization or Single Nucleotide Polymorphism array.

RESULTS:

A subtelomeric aberration was identified in 3.7% of patients (16/436). Details on subtelomeric aberrations and confirmation analyses are discussed.

CONCLUSION:

This is the first study describing the presence of subtelomeric rearrangements in individuals with ID in Indonesia. Furthermore, it shows that also in Indonesia such abnormalities are a prime cause of ID and that in developing countries with limited diagnostic services such as Indonesia, it is important and feasible to uncover the genetic etiology in a significant number of cases with ID.     

Recombination in human leukocyte antigen region in two Asian Indian families

BACKGROUND:

Recombination (crossing over) may generate novel haplotypes that can be beneficial to a population against recently introduced pathogens. It may lead to the generation of new alleles.

SETTINGS AND DESIGN:

A prospective study at a tertiary care centre.

AIM:

To report two rare cases of crossing over in HLA region.

MATERIALS AND METHODS:

Tissue-typing was done by sequence specific primers (SSP) for DR locus and by both SSP and serology for Class I which was reconfirmed on fresh samples.

RESULTS:

In one patient crossing over had taken place in the region of A locus resulting in inheritance of A*01 instead of expected A*11. In second family crossing over had taken place in region of DRB1 locus and the sibling inherited DRB1*08 instead of DRB1*10.

CONCLUSIONS:

Possibility of recombination must be considered when interpreting implausible tissue-typing results of families worked up for BMT.     

Rapid detection of chromosome X,Y, 13, 18, and 21 aneuploidies by primed in situ labeling/synthesis technique

AIMS AND OBJECTIVE:

Primed in situ labeling/synthesis (PRINS) technique is an alternative to fluorescent in situ hybridization for chromosome analysis. This study was designed to evaluate the application of PRINS for rapid diagnosis of common chromosomal aneuploidy.

MATERIALS AND METHODS:

We have carried out PRINS using centromere specific oligonucleotide primers for chromosome X, Y, 13, 18 and 21 on lymphocyte metaphase and interphase cells spread. Specific primer was annealed in situ, followed by elongation of primer by Taq DNA polymerase in presence of labeled nucleotides. Finally, reaction was stopped and visualized directly under fluorescent microscope.

RESULTS:

Discrete centromere specific signals were observed with each primer.

CONCLUSION:

PRINS seems to be a rapid and reliable method to detect common chromosome aneuploidy in peripheral blood lymphocyte metaphase and interphase cells.     

Divergent selection in trailing- versus leading-edge populations of Biscutella laevigata

Background and Aims

Knowledge on how climate-induced range shifts might affect natural selection is crucial to understand the evolution of species ranges.

Methods

Using historical demographic perspectives gathered from regional-scale phylogeography on the alpine herb Biscutella laevigata, indirect inferences on gene flow and signature of selection based on AFLP genotyping were compared between local populations persisting at the trailing edge and expanding at the leading edge.

Key Results

Spatial autocorrelation revealed that gene flow was two times more restricted at the trailing edge and genome scans indicated divergent selection in this persisting population. In contrast, no pattern of selection emerged in the expanding population at the leading edge.

Conclusions

Historical effects may determine different architecture of genetic variation and selective patterns within local populations, what is arguably important to understand evolutionary processes acting across the species ranges.     

Prevalence of methylenetetrahydrofolate reductase C677T polymorphism in eastern Uttar Pradesh

AIM:

This study was aimed to evaluate the 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation in eastern Uttar Pradesh population.

MATERIALS AND METHODS:

Polymerase chain reaction (PCR) using specific primers followed by amplicon digestion by Hinf I restriction enzyme was used for MTHFR C677T polymorphism analysis. Total 250 subjects were analyzed.

RESULTS:

The CC genotype was found in 192 subjects, followed by CT in 56 subjects and TT in 2 subject. Genotype frequencies of CC, CT and TT were 0.768, 0.224 and 0.008, respectively. The frequency of C allele was found to be 0.88 and that of T allele was 0.12.

CONCLUSION:

It is evident from the results of the present study that the percentage of homozygous genotype (CC) is highest in the target population.     

The NQO1 allelic frequency in hindu population of central India varies from that of other Asian populations

CONTEXT:

The enzymes encoded by the polymorphic genes NAD (P) H: quinone oxidoreductase 1 (NQO1) play an important role in the activation and inactivation of xenobiotics. This enzyme has been associated with xenobiotic related diseases, such as cancer, therapeutic failure and abnormal effects of drugs.

AIM:

The aim of the present study was to determine the allelic and genotypic frequencies of NQO Hinf I polymorphisms in a Hindu population of Central India.

SETTINGS AND DESIGN:

Polymorphisms of NQO1 were determined in 311 unrelated Hindu individuals.

MATERIALS AND METHODS:

Polymerase chain reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) analysis in peripheral blood DNA for NQO1 Hinf I polymorphism was used in 311 unrelated Hindu individuals.

STATISTICAL ANALYSIS:

Allele frequencies were calculated by direct counting. Hardy Weinberg Equilibrium was evaluated using a Chi-square goodness of fit test.

RESULTS:

The observed allelic frequency was 81% for C (wild) and 19% for T (mutant) in the total sample.

CONCLUSIONS:

The allelic frequency of “C” was higher than in other Asians (57%), but similar to Caucasians (81%). The genotype distributions for Hinf I polymorphisms were in Hardy-Weinberg equilibrium.     

Non-ischemic cardiomyopathy patients derive superior mortality benefit from cardiac resynchronization therapy

Background

Cardiac Resynchronization Therapy (CRT) is indicated for the treatment of advanced heart failure with severe systolic dysfunction and intraventricular conduction delay. Patient selection for this technology is vital, though it remains unclear which patients benefit most from CRT. We tested the hypothesis that patients with non-ischemic cardiomyopathy have a superior mortality benefit from CRT than ischemic cardiomyopathy patients.

Methods

We evaluated 95 CRT patients to determine which factors predict mortality.

Results

Patients with non-ischemic cardiomyopathy had a significantly better prognosis than patients with ischemic cardiomyopathy.

Conclusion

Larger prospective studies can substantiate this finding and better delineate which patients benefit most from CRT.     

Distribution of CC-chemokine receptor-5-?32 allele among the tribal and caste population of Vidarbha region of Maharashtra state

BACKGROUND:

Genetic relationships among the ethnic groups are not uniform across the geographical region. Considering this assumption, we analyzed the frequency of the CC-chemokine receptor-5 (CCR5)-∆32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in Bhil tribal and Brahmin caste sample sets from the population.

MATERIALS AND METHODS:

108 blood samples were collected from 6 tribe''s populations and a caste population from the district of Vidarbha region.

RESULTS AND DISCUSSION:

The presence of low frequencies of CCR5-Δ32 in an individual of Bhil tribe (0.034, χ² value 0.017) in the present study implies that these communities may have a better resistance toward human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) than the other studied tribe sample, as non-show such mutation.

CONCLUSION:

The marginal presence of the allele seen in the studied tribal population could be due to gene flow from the people of European descent. However, lack of the homozygous CCR5-Δ32 mutation and the low prevalence of heterozygous CCR5-Δ32 mutations suggest that the Indians are highly susceptible to HIV/AIDS, and this correlates with the highest number of HIV/AIDS infected individuals in India.     

Human sex ratio at birth in South West Nigeria

BACKGROUND:

Human sex ratio at birth differs from one population to the other. This variation has been attributed to cultural practices, seasonal variation, small-family size policy and sex selective technology. Information on secondary sex ratio in Nigeria is limited.

AIMS AND OBJECTIVE:

To analyzed human sex ratio at birth for samples of the Nigerian population in 4 urban settings in Southwest Nigeria, in order to know the trend and to compare the findings with those of previous reports.

MATERIALS AND METHODS:

Data were collected from Obafemi Awolowo University (OAU) teaching hospital at Ile Ife and Wesley Guild hospital at Ilesa, Osun state; General hospital at Ogbomoso, Oyo state and Ekiti state specialist hospital at Ado-Ekiti, Ekiti state. The data consisted of 35 209 live single births recorded between 1995 and 2004. Each set of data was analyzed to determine the sex ratio by year, month and quarterly values. Chi-square analysis was used to determine the deviation of the sex ratios for the years from the average value.

RESULTS:

The annual average ratios of 104.7:100, 102.8:100, 98.9:100 and 100.8:100 were recorded for OAU teaching hospital, Wesley Guild Hospital, General Hospital and Ekiti State specialist hospital, respectively. When pooled together, the average ratio was 102.7:100. This shows some bias for male births. Data also indicates more male birth in the rainy season, suggesting a seasonal variation of sex ratio.

CONCLUSION:

These findings are representative of the populations in southwest Nigeria and are comparable to values obtained for other regions in Nigeria and other populations of African origin.     

Evolution of phenylthiocarbamide taster trait in Mysore, South India

BACKGROUND:

The ability to taste phenylthiocarbamide (PTC), a bitter chemical has long been known to be a heritable trait, which is being widely used for both genetic and anthropological studies. The frequency of taster and non-taster allele is found to vary in different populations.

AIMS AND OBJECTIVE:

To investigate the frequency of taster trait in Mysore, South India.

MATERIALS AND METHODS:

The present investigation was conducted in Mysore, South India during 2002 - 2003. About 3282 subjects irrespective of age, sex, religion, food habits, socio-economic status were randomly selected from various parts of the city and a total of 180 families, which included Christian (50), Hindu (61) and Muslim (69) were screened from different localities of the city. Harris and Kalmus method was used to assess the PTC taster and nontaster phenotype.

RESULTS:

It was found that tasters were significantly more frequent than nontasters in all the four categories. The incidence of tasters was more in unbiased category (85%) and less in Muslim category (58%). Investigations on PTC tasting in the families of three different religious groups revealed that the tasters were significantly more frequent than nontasters. It was also found that heterozygous father or mother for the taster genes with nontaster partner had taster and nontaster progenies in the ratio 1.0: 1.54 indicating the deviation in the segregation pattern of test cross.

CONCLUSION:

In Mysore, tasters are more frequent than nontasters. Variation in the frequency of nontaster allele in the religious groups could be due to inbreeding.