Riverine status and genetic structure of Chilika buffalo of eastern India as inferred from cytogenetic and molecular marker-based analysis

Genetic characterization and diversity assessment in 'Bhangor' indigenous swamp buffalo population using heterologous microsatellite markers

'Bhangor' newly identified swamp buffalo population from North East Indian, was characterized using microsatellite markers. Genomic DNA was isolated from blood samples of 76 unrelated animals, 15 microsatellite markers (CSSM33, BM1818, CSRM60, HEL13, ILSTS019, ILSTS025, ILSTS028, ILSTS029, ILSTS033, ILSTS036, ILSTS056, ILSTS058, ILSTS061, ILSTS089 and ETH003) were found to be highly polymorphic in the population of the selected markers. A total of 114 alleles were observed, which ranged from 3 in CSRM60 and ILSTS025 locus to 12 in ILSTS056 and ILSTS061. The mean effective number of alleles across all polymorphic loci was found to be 3.76. The overall mean expected heterozygosity and unbiased expected heterozygosity values were 0.67 and 0.68, ranging from 0.067 (ILSTS025) to 0.85 (ILSTS058) and 0.068 (ILSTS025) to 0.86 (ILSTS058), respectively. Within the population, the inbreeding estimates (FIS) ranged between -0.4352 and 0.804, with an average FIS of 0.114 ± 0.033. The outcome for infinite allele model (IAM), two-phase model (TPM) and test for mode shift revealed the absence of any recent bottleneck in the investigated buffalo population. The population was found to be in optimum diversity based on polymorphic microsatellite markers. With fast changing agro-climatic conditions; there is an urgent need to characterize the nondescript livestock populations.

Current status and unique attributes of Indian Chilika buffalo for adaptation to brackish water ecology

Chilika buffalo is native to the Eastern coast of India and well adapted to the largest coastal brackish water lagoon of Asia, Chilika Lake. We present here a report on the Chilika buffalo breed emphasizing the conservational urgency based on unique biochemical and molecular evidence related to liver and kidney functions while comparing it with tropically adapted other water buffalo breeds (Bubalus bubalis) of India. It is found that the Chilika buffalo breed has a better ability to withstand a long dehydration period as evident from its better glomerular filtration and higher expression of the ion transport channel. Mitochondrial D-loop sequencing results have shown these buffaloes being closer to swamp-type buffaloes of Bangladesh and northeast India and represent a unique "hybrid zone" on the eastern coast of India. Conservation of such uniquely adapted germplasm is crucial owing to the current global trend, where the introduction of exotic breeds has negatively impact "sui-generis" germplasm and they require higher managerial resource consumption for maintaining higher productivity. Further, the introduction of unconventional fisheries activities has proved detrimental to the lagoon ecosystem, potentially causing more threat to the buffalo's population.

Mitochondrial sequence-based evolutionary analysis of riverine-swamp hybrid buffaloes of India indicates novel maternal differentiation and domestication patterns

In this study, mitochondrial D-loop sequence data on riverine, swamp and hybrid buffaloes from India have been generated and compared with other reported Indian riverine, Chinese and Bangladeshi swamp buffalo populations. Sequence analysis revealed the presence of 132 haplotypes, with a haplotype diversity of 0.9611 ± 0.0045 and a nucleotide diversity of 0.04801 ± 0.00126. For the first time, the existence of riverine-swamp hybrids among the Indian Chilika buffalo population has been recorded, having 49 chromosomes, which was also confirmed by mitochondrial haplotype sharing between Chilika and Indian swamp as well as Chinese swamp buffalo populations in the network analysis. Phylogenetic analysis documents the sharing of reported pre-domestication haplogroups 'SA1', 'SA2', 'SA3' and 'SB1' between the Chilika and swamp buffalo populations of India, China and Bangladesh, an indication of the migration of swamp buffaloes towards Bangladesh and adjoining lower parts of India and north towards Chinese domestication sites. The results have also been supplemented by multidimension scaling, grouping Indian and Chinese swamp buffaloes more closely together with Bangladeshi buffaloes, but into a separate quadrant, whereas Chilika grouped away from other riverine as well as swamp buffaloes. These findings thus confirm the previous reports that the northeast region of India, close to the Indo-China border, is the point of evolution of swamp buffaloes with multiple sites of domestication.

Elucidating the genetic diversity using SSR based markers in Gojri buffalo

A population based study was conducted in a large sample of Gojri buffalo, a less known dairy buffalo from Northern India, to assess its genetic variations using 25 heterologous simple sequence repeats (SSR) marker loci. Primers for markers used in the study were labelled either with VIC, NED, PET or FAM dye. Genotyping of each sample was performed by sequencing the PCR amplicons and thereby, estimating diversity indices based on frequency of different allele sizes. Gojri buffalo had an average of 8.2 alleles per locus with 3.65 mean effective number of locus. The polymorphic information content (PIC) values for studied SSR markers ranged from 0.11–0.81, indicating that all the markers, except ILSTS 19, were informative and suitable for the diversity analysis in the buffalo population. The average observed heterozygosity (Ho) and unbiased expected heterozygosity (uHe) estimate were 0.67 and 0.70, respectively in the population with majority of the markers showing Hardy Weinberg equilibrium. A higher expected heterozygosity in Gojri population indicates presence of sufficient genetic diversity, and a higher overall mean of Shannon’s information index (1.5) support these findings. Moreover, both genetic Bottleneck and Mode Shift analysis indicated absence of genetic bottleneck in the recent past among the studied Gojri population. Population inbreeding estimates (FIS=0.029) indicated an average deficiency of 2.9% and suggests no probable inbreeding in the population. It can be concluded that there is presence of sufficient genetic variations in Gojri population and this information can augment in designing its breeding and conservation programme.

Genetic characterization and assessment of diversity in Pandharpuri buffalo breed of India using heterologous microsatellite markers

The present study was aimed at genetic characterization and diversity analysis of Pandharpuri buffalo population using the Food and Agriculture Organization (FAO) recommended bovine microsatellite markers. Genomic DNA was isolated from blood samples of 50 unrelated animals and a total of 23 microsatellite loci were amplified using polymerase chain reaction. Among 23 recommended microsatellite markers, 14 markers (BM2113, BM1818, CSSM66, HEL13, INRA037, ILSTS05, HAUT27, INRA023, INRA035, HEL5, ETH3, NRA063, MM12 and ETH10) were found to be highly polymorphic in Pandharpuri population. The amplified products were run on polyacrylamide gel electrophoresis (PAGE) apparatus along with a ladder; subsequently, the allele typing was done based on silver staining of the gel. The effective and observed number of alleles, heterozygosity (expected and unbiased) estimates and polymorphic information content (PIC) levels were estimated for each locus. A total of 87 alleles were secured for 14 polymorphic loci studied giving an overall average of 6.21 alleles per locus. The number of alleles ranged from 2 (INRA063) to 9 (BM1818 and HEL13). The mean effective number of alleles across all polymorphic loci was found to be 4.28. The overall mean expected heterozygosity and unbiased expected heterozygosity values were 0.77 and 0.76, ranging from 0.50 (INRA063) to 0.88 (BM1818) and 0.50 (INRA063) to 0.88 (BM1818), respectively. The average PIC estimate across all polymorphic loci was 0.73 ranging from 0.373 (INRA063) to 0.864 (BM1818). In the present study, the characterization and diversity estimates are reported for Pandharpuri population. It was found to maintain optimum diversity based on 14 polymorphic microsatellite markers.

Cytogenetic characterization of Sambalpuri and Manda buffaloes of Odisha

Cytogenetics analysis even though mostlyused for the evaluation of chromosomal abnormality by arresting the cell division at metaphase stage, but is also helpful to ascertain the riverine/swamp status of buffaloes. The study was conducted to characterize two buffalo populations, viz. Sambalpuri and Manda of Odisha cytogenetically, to establish their riverine or swamp status. Metaphase chromosome spreads ofboth, Sambalpuri and Manda buffaloes showed a chromosome number of 2n=50.There were fivepairs of metacentric or sub-metacentric and 19 pairs acrocentric along with a pair of sex chromosomesin both the populations, typical of riverine buffalo. Nomorphological or chromosomal abnormality observed in any of the populations. This study thus confirms the riverine status of both the Odisha buffalo populations.

Microsatellite based Genetic Variation among the Buffalo Breed Populations in Pakistan

Introduction

Eight microsatellite loci were used to define genetic diversity among five native water buffalo breeds in Pakistan.

Material and Methods

Blood samples (10 mL) from 25 buffaloes of each of the Nili, Ravi, Nili-Ravi, Kundhi, and Azi-Kheli breeds were collected aseptically from the jugular vein into 50 ml Falcon tubes containing 200 µl of 0.5 M EDTA. The phenol-chloroform method was used to extract DNA and the regions were amplified for microsatellite analysis. The eight microsatellite markers ETH10, INRA005, ILSTS029, ILSTS033, ILSTS049, ILSTS052, ETH225, and CSSM66 were analysed.

Results

The effective number of alleles across all loci was as usual lower than the observed values with a mean value of 2.52 alleles per locus. The overall allele frequency varied from 0.0041 for alleles B, I, and J over respective loci ILSTS052, INRA005, and ILSTS029 to 0.80 for allele H over locus ILSTS029. The average observed and expected heterozygosity values across all polymorphic loci in all studied buffalo breeds were 0.43 and 0.53, respectively. The overall value for polymorphic information content of considered microsatellite markers was 0.53, suggesting their appropriateness for genetic diversity analysis in buffalo. The mean Fis value was 0.13 and all loci except ILSTS049 were found significantly deviated from HWE, most likely due to non-random breeding. The five buffalo populations were genetically less diverse as indicated by a small mean Fst value (0.07). The average gene flow (Nm) indicative for population migration was calculated as 3.31. Nei’s original measures of genetic distance (Ds) revealed ancient divergence of the Nili and Azi-Kheli breeds (Ds = 0.1747) and recent divergence of the Nili and Ravi breeds (Ds = 0.0374).

Conclusion

These estimates of genetic diversity were seen to coincide with phenotypic differentiation among the studied buffalo breeds. The present study reports the first microsatellite marker-based genetic diversity analysis in Pakistani buffalo breeds, and might facilitate similar studies in other livestock breeds of Pakistan.

Genetic diversity analysis of buffalo fatty acid synthase (FASN) gene and its differential expression among bovines

Fatty Acid Synthase (FASN) gene seems to be structurally and functionally different in bovines in view of their distinctive fatty acid synthesis process. Structural variation and differential expression of FASN gene is reported in buffalo (Bubalus bubalis), a bovine species close to cattle, in this study. Amino acid sequence and phylogenetic analysis of functionally important thioesterase (TE) domain of FASN revealed its conserved nature across mammals. Amino acid residues at TE domain, responsible for substrate binding and processing, were found to be invariant in all the mammalian species. A total of seven polymorphic nucleotide sites, including two in coding region of TE domain were identified across the 10 buffalo populations of riverine and swamp types. G and C alleles were found almost fixed at g18996 and g19056 loci, respectively in riverine buffaloes. Principal component analysis of three SNPs (g18433, g18996 and g19056) revealed distinct classification of riverine and swamp buffalo populations. Reverse Transcription-PCR amplification of mRNA corresponding to exon 8-10 region of buffalo FASN helped in identification of two transcript variants; one transcript of 565 nucleotides and another alternate transcript of 207 nucleotides, seems to have arisen through alternative splicing. Both the transcripts were found to be expressed in most of the vital tissues of buffalo with the highest expression in mammary gland. Semi-quantitative and real-time expression analysis across 13 different buffalo tissues revealed its highest expression in lactating mammary gland. When compared, expression of FASN was also found to be higher in liver, adipose and skeletal muscle of buffalo tissues, than cattle. However, the FASN expression was highest in adipose among the three tissues in both the species. Results indicate structural and functional distinctiveness of bovine FASN. Presence of alternate splicing in buffalo FASN also seems to be a unique phenomenon to the bovines, probably associated with mRNA based regulation of the biological functions of FASN in these species.

Assessment of genetic variability and structuring of riverine buffalo population (Bubalus bubalis) of Indo-Gangetic basin

The buffalo population of Uttar Pradesh (UP) constitutes 26.1% of the total buffalo population of India, yet this population has not been classified into distinct breeds or subpopulations due to lack of systematic study. Genetic variation at 30 microsatellite loci was examined and statistical analysis was carried out to reveal genetic diversity, demographic parameters of these buffaloes and to investigate the existence of population substructures underlying geographical distribution. The mean number of alleles per locus was 13.26 and mean effective number of alleles was 3.74, whereas mean observed and expected heterozygosities were found to be 0.57 and 0.67 in UP buffaloes. Principal component analysis (PCA) based on allele frequency data revealed subclustering of UP buffalo population. Bayesian analysis result also revealed clear membership of individuals into five clusters indicating a genetic subdivision within the UP buffalo population. The buffaloes of Western and Central regions of UP were subtly separated while buffaloes of Tarai area and Bhadawari buffaloes revealed distinctive population structure. The buffaloes of Mau, Ballia and Ghazipur districts of Eastern region also had a distinctive genetic structure. The analysis of data on buffaloes of Indo-Gangetic plains revealed that population was in mutation drift equilibrium. The observed mean M ratio in the population was above the critical significance value (Mc) suggesting that it has not suffered any severe reduction in effective population size. The statistical tests revealed a historical constancy of size of buffalo in this geographical area. The high level of genetic variability indicates UP buffalo population is a vast reservoir of genetic diversity and this shall help in taking informed conservation decisions and sustainable utilization.

Power of exclusion of 19 microsatellite markers for parentage testing in river buffalo (Bubalus bubalis)

In the present study, 19 microsatellite markers were assessed for their power of exclusion to test parentage in river buffalo. Microsatellite genotypes of 216 unrelated buffaloes belonging to five different breeds were utilized for the study. The probabilities of exclusion were calculated for three hypothetical situations viz. paternity testing (PE1), one parental genotype unavailable (PE2) and exclusion of both parents i.e. substituted offspring (PE3). The mean probability of exclusion across 19 investigated markers in buffalo was 0.578 (PE1), 0.405 (PE2) and 0.764 (PE3) respectively. The probability of exclusion for paternity (PE1) ranged between 0.297 and 0.814 across different markers. The exclusion probability for the cases one parent unavailable (PE2) and substituted offspring (PE3) varied from 0.143 to 0.688 and 0.465 to 0.946 respectively. Polymorphism information content and expected heterozygosity were found to have significantly high correlation with probability of exclusion of microsatellite markers. The cumulative PE1 of nine marker loci was estimated to be 0.9999 while in case of absence of one of the parental genotypes, a minimum of 11 markers were required to achieve a cumulative PE2 of 0.999. In conclusion, the present study proposes two multiplex sets with four and five markers respectively for routine parentage testing in buffalo and an additional set of four markers for doubtful cases of paternity.

Evaluation of ISSR markers for genetic diversity analysis in Anatolian water buffaloes

BACKGROUND

The utilisation of molecular markers has increased in molecular research recently. Inter-simple sequence repeat (ISSR) markers allow the analysis of genomes without preliminary sequence information, since random primers are used. The purpose of the present study was to evaluate ISSR markers for assessing the genetic diversity of indigenous Anatolian Water Buffaloes reared in Afyon, Konya and Sivas provinces of Turkey, with a view to conservation of the gene resources.

RESULTS

The 11 ISSR primers chosen for the analysis revealed a total of 110 bands, of which 76 (69.09%) were polymorphic. Also, genetic similarity, polymorphic information content (PIC), resolving power (R(p)) and mean resolving power (R(p)), heterozygosity (H) and Shannon index (I) were calculated as 0.9479-0.9562, 0.35 ± 0.20, 2.73, 0.27, 0.18 ± 0.07 and 0.28 ± 0.11, respectively.

CONCLUSION

The ISSR markers were found to be promising for assessing the genetic diversity in buffalo populations. Potential genetic parameters such as PIC, R(p), R(p), H and I were effectively used in this study.

Y-chromosomal variation confirms independent domestications of swamp and river buffalo

Y-chromosomal variation in the water buffalo was analysed by sequencing of DBY, ZFY and SRY gene segments. A clear separation of the paternal lineages of the river and swamp types parallels the differences between their maternal lineages and nuclear DNA. Sequence divergence was found to be comparable to the divergence of taurine cattle and zebu, and this divergence predated domestication, confirming that river and swamp buffalo originated from different wild populations. Within a sample of 23 Thai swamp buffaloes, we identified four haplotypes with different geographical distributions, two of which were shared by Thai wild buffaloes.