BackgroundThe IS6110 insertion sequence, a member of the IS3 family of insertion sequences, was found to be specific to the Mycobacterium tuberculosis complex (MTBC). Although IS6110 has been extensively characterized as a transposable genetic marker, the evolutionary history of its own transposase-encoding sequence has not, to the best of our knowledge, been investigated.Methodology/Principal FindingsHere we explored the evolution of the IS6110 sequence by analysing the genetic variability and the selective forces acting on its transposase-encoding open reading frames (ORFs) A and B (orfA and orfB). For this purpose, we used a strain collection consisting of smooth tubercle bacilli (STB), an early branching lineage of the MTBC, and present-day M. tuberculosis strains representing the full breadth of genetic diversity in Tunisia. In each ORF, we found a major haplotype that dominated over a flat distribution of rare descendent haplotypes, consisting mainly of single- and double-nucleotide variant singletons. The predominant haplotypes consisted of both ancestral and present-day strains, suggesting that IS6110 acquisition predated the emergence of the MTBC. There was no evidence of recombination and both ORFs were subjected to strict purifying selection, as demonstrated by their dN/dS ratios (0.29 and 0.51, respectively), as well as their significantly negative Tajima’s D statistics. Strikingly, the purifying selection acting on orfA proved much more stringent, suggesting its critical role in regulating the transpositional process. Maximum likelihood analyses further excluded any possibility of positive selection acting on single amino acid residues.Conclusions/SignificanceTaken together our data fit with an evolutionary scenario according to which the observed variability pattern of the IS6110 transposase-encoding ORFs is generated mainly through random point mutations that accrued on a functionally optimal IS6110 copy, whose acquisition predated the emergence of the MTBC complex. Background selection acting against deleterious mutations led to an excess of low-frequency variants.

IS6110-5'3'FP demonstrated sufficient potential to be a promising automated alternative to IS6110 RFLP, amenable to high throughput analysis and inter-laboratory comparison.

This study was conducted on 150 (one hundred and fifty) Clarias gariepinus to investigate the blood lipids (triglycerides and cholesterol), kidney functions (creatinine and urea), liver functions (ALT -AST -ALP -LDH), antioxidants (CAT -SOD -GPx) and growth performance (body weight and weight gain). The study was designed by dividing the fish into 3 groups: Group 1: (Control Group), Group 2: (2.4 mg manganese oxide nanoparticles/kg ration) and Group 3 (1.2 mg manganese oxide nanoparticles/kg ration). Samples were collected on day 15, 30, 45 and 60 of the experiment and blood samples were collected for serum separation. The results of this study indicated that the 2 nd group exhibited a significant and progressive decrease in triglycerides, cholesterol, ALT, AST, ALP, LDH, creatinine and urea at all experiment times compared to the control group. Shifting to the antioxidants, the 2 nd and 3 rd groups showed a significant increase in CAT, SOD and GPx levels in the serum compared with the control group at day 60 of the experiment. Concerning the results of growth performance, both groups reflected a significant improvement in body weight and weight gain compared with the control group.