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author:("Singh, ladji")
2.  Ancient origin and evolution of the Indian wolf: evidence from mitochondrial DNA typing of wolves from Trans-Himalayan region and Pennisular India 
Genome Biology  2003;4(6):P6.
A study of mitochondrial DNA diversity across three different taxonomically informative domains (cytochrome-B gene, 16S rDNA and hypervariable d-loop control region) revealed that the Himalayan wolf and the Indian Gray wolf are genetically distinct from each other as well as from all other wolves of the world
The two wolf types found in India are represented by two isolated populations and believed to be two sub-species of Canis lupus. One of these wolf, locally called Himalayan wolf (HW) or Tibetan wolf, is found only in the upper Trans-Himalayan region from Himachal Pradesh to Leh in Kasmir and is considered to be C. lupus chanco. The other relatively larger population is of Indian Gray wolf (GW) that is found in the peninsular India and considered to be C. lupus pallipes. Both these wolves are accorded endangered species status under the Indian Wildlife Protection Act. In 1998 for the first time in India, we initiated molecular characterization studies to understand their genetic structure and taxonomic status. Since then, we have analyzed the genetic variability in 18 of the total of 21 HW samples available in Zoological parks along with representative samples of GW, wild dogs and jackals. Our study of mitochondrial DNA diversity across three different taxonomically informative domains i.e., cytochrome-B gene, 16S rDNA and hypervariable d-loop control region revealed HW to be genetically distinct from the GW as well as from all other wolves of the world, including C. lupus chanco from China. Most importantly, d-loop haplotypic diversity revealed both HW and GW from India to be significantly diverse from other wolf populations globally and showed that these represent the most ancient lineages among them. Phylogenetic analysis revealed the Indian wolves as two independent lineages in a clade distinct and basal to the clade of all wolves from outside of India. Conservative estimate of evolutionary time-span suggests more than one million years of separation and independent evolution of HW and GW. We hypothesize that Indian wolves represent a post-jackal pre-wolf ancestral radiation that migrated to India about 1-2 mya and underwent independent evolution without contamination from other wolf like canids. The study thus, suggests that Indian subcontinent had been one major center of origin and diversification of the wolf and related canids. Further, the significant degree of genetic differentiation of HW from GW and of these two from other wolves, suggest the interesting possibility of them to be new wolf species/subspecies in evolution that may need to be described possibly as C. himalayaensis and C. indica (or as C. lupus himalyaensis and C. lupus indica), respectively. Thus for the first time, the study reveals new ancient wolf lineages in India and also highlights the need to revisit the origin, evolution and dispersion of wolf populations in Asia and elsewhere. Simultaneously, it increases the conservation importance of Indian wolves warranting urgent measures for their effective protection and management, especially of the small HW population that at present is not even recognized in the canid Red List.
doi:10.1186/gb-2003-4-6-p6
PMCID: PMC4071266
3.  Genome-wide analysis of microsatellite repeats in humans: their abundance and density in specific genomic regions 
Genome Biology  2003;4(2):R13.
Simple sequence repeats are found in most organisms, and occupy about 3% of the human genome. The densities of simple sequence repeats across the human chromosomes were found to be relatively uniform. Tri- and hexa-nucleotide repeats are more abundant in exons, whereas other repeats are more abundant in non-coding regions.
Background
Simple sequence repeats (SSRs) are found in most organisms, and occupy about 3% of the human genome. Although it is becoming clear that such repeats are important in genomic organization and function and may be associated with disease conditions, their systematic analysis has not been reported. This is the first report examining the distribution and density of simple sequence repeats (1-6 base-pairs (bp)) in the entire human genome.
Results
The densities of SSRs across the human chromosomes were found to be relatively uniform. However, the overall density of SSR was found to be high in chromosome 19. Triplets and hexamers were more predominant in exonic regions compared to intronic and intergenic regions, except for chromosome Y. Comparison of densities of various SSRs revealed that whereas trimers and pentamers showed a similar pattern (500-1,000 bp/Mb) across the chromosomes, di- tetra- and hexa-nucleotide repeats showed patterns of higher (2,000-3,000 bp/Mb) density. Repeats of the same nucleotide were found to be higher than other repeat types. Repeats of A, AT, AC, AAT, AAC, AAG, AGC, AAAC, AAAT, AAAG, AAGG, AGAT predominate, whereas repeats of C, CG, ACT, ACG, AACC, AACG, AACT, AAGC, AAGT, ACCC, ACCG, ACCT, CCCG and CCGG are rare.
Conclusions
The overall SSR density was comparable in all chromosomes. The density of different repeats, however, showed significant variation. Tri- and hexa-nucleotide repeats are more abundant in exons, whereas other repeats are more abundant in non-coding regions.
doi:10.1186/gb-2003-4-2-r13
PMCID: PMC151303  PMID: 12620123
4.  MRD: a microsatellite repeats database for prokaryotic and eukaryotic genomes 
Genome Biology  2002;3(12):preprint0011.1-preprint0011.13.
Microsatellite repeats database (MRD) is a database system to access the microsatellite repeat information for eukaryotic genomes. Users can search for the repeat of interest and find its non-coding features and its abundance and distribution in the genome. The exact location of repeats with respect to genomic regions of interest whichever is applicable to the organism is highlighted.
MRD is a database system to access the microsatellite repeats information of genomes such as archea, eubacteria, and other eukaryotic genomes whose sequence information is available in public domains. MRD stores information about simple tandemly repeated k-mer sequences where k= 1 to 6, i.e. monomer to hexamer. The web interface allows the users to search for the repeat of their interest and to know about the association of the repeat with genes and genomic regions in the specific organism. The data contains the abundance and distribution of microsatellites in the coding and non-coding regions of the genome. The exact location of repeats with respect to genomic regions of interest (such as UTR, exon, intron or intergenic regions) whichever is applicable to organism is highlighted. MRD is available on the World Wide Web at http://www.ccmb.res.in/mrd and/or http://www.ingenovis.com/mrd. The database is designed as an open-ended system to accommodate the microsatellite repeats information of other genomes whose complete sequences will be available in future through public domain.
doi:10.1186/gb-2002-3-12-preprint0011
PMCID: PMC4071243  PMID: 12537551

Results 1-4 (4)