Assessing the variability of telomere length measures by means of Telomeric Restriction Fragments (TRF) in different tissues of cod Gadus morhua

The chronological age estimation is still an elusive parameter in many wild animals. Telomeres are nucleoprotein on the ends of chromosomes that shorten throughout the life of many animals. In this study, Telomeric Restriction Fragments length was measured in four different tissues (brain, liver, muscle and skin) of aquaculture cods (Gadus morhua) of different age: larvae (0-110 dph); fry (111-180 dph), juvenile (181-420 dph) and adults (> 421 dph). Telomeres shortened with increasing age and body length, with differences in telomere rate of shortening depending on the tissue and the developmental stage. The shortening of telomeres with age was significant in brain and liver but it was observed inter-individual variability among individuals of the same age class. Skin and muscle showed no significant shortening pattern with age even tending to elongate in the case of muscle.