(a) Analysis of ectopic expression of HAT4-FLAG in rescue line. Western blot analysis of whole cell lysates isolated from LdHAT4-KO cells, LdHAT4-KO cells harbouring empty vector (LdHAT4-KO/bleo), and LdHAT4-KO cells expressing HAT4-FLAG (LdHAT4-KO/HAT4-FLAG). Anti-FLAG antibody (Sigma Aldrich) and anti-tubulin antibody (Zymed, USA) were used at 1:1000 and 1:5000 dilution respectively. (b) Growth analysis. Growth pattern of the rescue line (LdHAT4-KO/HAT4-FLAG) was compared with that of knockout line harbouring empty vector (LdHAT4-KO/bleo), and with Ld1S either harbouring empty vector (Ld1S/bleo) or expressing HAT4-FLAG episomally (Ld1S/HAT4-FLAG). (c) Analysis of cell survival. Percent LdHAT4-KO/HAT4-FLAG survivors was compared with percent survivors in knockout line LdHAT4-KO, as well as Ld1S/bleo and Ld1S/HAT4-FLAG lines, every 24 hrs over a period of seven days. For growth and survival analyses, three biological replicates were initiated and carried out in parallel, and mean values are presented, with error bars indicating standard deviation. Student’s t-test (two-tailed) was applied to analyze the data. P values obtained: *p < 0.05, **p < 0.005, ***p < 0.0005.