This study was aimed to investigate genetic diversity, phylogenetic relationship and maternal origin of Bangladeshi indigenous sheep population based on mitochondrial DNA (mtDNA) displacement loop (D-loop) region. A total of 62 unrelated indigenous sheep samples from 4 different geographical regions (Sundarban delta region=SDR, Jamuna river basin=JRB, Coastal region=COR and Barind tract=BAT) were investigated using 444 bp mtDNA D-loop sequence fragment. Sequence analysis revealed only 10 variable sites that defined 11 haplotypes. The estimated haplotypes diversity and nucleotide diversity were 0.401 ± 0.149 and 0.002 ± 0.001, respectively. The population pairwise FST values were highly significant (p <0.01) between COR and three other sheep populations (SDR, JRB and BAT) that ranged between 0.037 and 0.352. Analysis of molecular variance (AMOVA) revealed that 88.84% of the total genetic variability was accounted for within population differentiation and the remaining 11.16% variability was distributed among sheep populations of four different regions of Bangladesh. The phylogenetic study did not show any distinct cluster among the Bangladeshi sheep populations but had evolutionary relationship with Ovis aries as well as with some other Indian, Chinese and Turkish sheep breeds. Altogether, the mtDNA sequence information showed lower genetic diversity and common matrilineage among the studied populations. In conclusion, this study provides important insight on genetic diversity measures and relationships among indigenous sheep population of Bangladesh. تفاصيل المقالة