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 Nordfjall and Professor G?¶ran Roos at the Division of Pathology, Department of Medical Biosciences, Umea University, and Research Engineer ?…sa Larfalk, Statistician Petter Lindgren, and Professor Dan Holmber, all three at the Division of Medical and Clinical Genetics, Department of Medical Biosciences, Umea University.

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"These results provided new insights into how the mosquito defends itself from the malaria parasite. More research is needed, but we plan to apply this knowledge in the development of new approaches to control the disease," said co-author Marcelo Jacobs-Lorena, PhD, a professor in the Department of Molecular Microbiology and Immunology and the Malaria Research Institute at the Bloomberg School of Public Health.

Abraham and Jacobs-Lorena are developing a transgenic mosquito in which the SPRN6 gene is permanently switched on, in an effort to create a mosquito that would be immune to the Plasmodium parasite. They believe that such a mosquito could help disrupt the transmission of malaria to humans.

"An immune-responsive serpin, SRPN6, mediates mosquito defense against malaria parasites" was Eappen G. Abraham, Sofia Pinto, Anil Ghosh, Dana L. Vanlandingham, Aidan Budd, Stephen Higgs, Fotis C. Kafatos, Marcelo Jacobs-Lorena and Kristin Michel. Abraham, Ghosh and Jacobs-Lorena are with the Johns Hopkins Bloomberg School of Public Health. Pinto, Budd, Kafatos and Michel are with the European Molecular Biology Laboratory in Heidelberg, Germany and the Imperial College of London. Vanlandingham and Higgs are with the Department of Pathology at the University of Texas Medical Branch.

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