Maximum longevity inherited from the father

The parts of the genetic make-up that are thought to determine an individual’s maximum possible longevity, so-called telomeres, are inherited from the father but not the mother. This is shown by a research team at Umeå University in the coming issue of the U.S. scientific journal Proceedings of the National Academy of Sciences.

Telomeres are genetic material with repetitive content at the ends of DNA, and their main function is believed to be to protect the rest of the genetic material from degradation. Telomeres are shortened each time a cell divides, which in broad terms means that the longer a cell’s telomeres are, the longer the individual can live, in theory. A person’s telomeres are shortened with age, which the findings of the study indeed show: telomeres were shortened by an average of 21 nitrogen base pairs per year in the subjects studied.

The study, soon to appear in the U.S. scientific journal PNAS, Proceedings of the National Academy of Sciences, was carried out on 132 healthy subjects in 49 different families with no close kinship to each other in northern Sweden. The subjects consisted of fathers and mothers (mean age 66 years) and their daughters and sons (mean age 37 years). Blood samples were taken, and mononuclear immune cells were culled.

Half of these were simply frozen, while the other half were infected with Epstein-Barr virus (EBV) and cultured for 18-55 days, whereupon the surviving cells were frozen. DNA was then extracted from both cell types using standardized techniques, and the length of the telomeres was ascertained.

The findings show that changes in the length of the telomeres in the cultured cells are determined by the original length of the telomeres, and the length of the telomeres in the second generation, both sons and daughters, proved to be inherited from the father.

The work was carried out by doctoral candidate Katarina Nordfjäll and Professor Göran Roos at the Division of Pathology, Department of Medical Biosciences, Umeå University, and Research Engineer Åsa Larfalk, Statistician Petter Lindgren, and Professor Dan Holmber, all three at the Division of Medical and Clinical Genetics, Department of Medical Biosciences, Umeå University.