Comparison of telomere lengths in leukocytes and in nasal and vaginal epithelial cells from Water Buffaloes (Bubalus bubalis) of different ages

Telomeres are short and repetitive sequences at the ends of linear chromosomes which shorten with every cell-division in vitro. Telomere length (TL) is reported to decrease with age and stress. The domesticated water buffalo (Bubalus bubalis) is the second most important milk producing animal worldwide. The productive lifespan of water buffalo cows is reported to be longer than that of dairy cows (Bos taurus). With this background, we aimed to compare TL in leukocytes obtained from blood samples from water buffaloes across different ages. In addition, we tested the suitability of assessing TL in DNA derived from nasal and vaginal epithelial cells via swabs as potential non-invasive alternatives to blood sampling Samples were collected from 20 calves (3 months of age), 20 heifers (2 years old), 20 cows (1st lactation, 3 years old), and 13 cows (3rd lactation, about 5 years old). We found that TL in leukocytes from water buffalo calves, heifers, and from cows in their first lactation was not different, but shorter telomeres were observed in cows in their third lactation. The results thus support an age-dependent decrease of TL in water buffaloes. Leukocyte TL was weakly correlated with TL measured in DNA from nasal epithelial cells (r = 0.327; P = .025), but not with TL from vaginal epithelial cells. Due to the poor correlation between epithelial cell and leukocyte TL and to the difficulties with collecting nasal swabs, we conclude that they are no suitable alternatives to blood samples for telomere studies in water buffaloes.