A Study Of Estimating Age Of Humans By Dermal,Intramuscular Telomere Length

Objective Through measure telomere length ( mean length of telomere restriction fragment, TRF) of dermal and intramuscular , and study it's length correlating with the different human ' s age. The TRF was examined by Southern blotting. The formula to age estimating was obtained by regression analysis between the TRF and the age. Compared different effecting of gender and territory to estimate age of human. Using of our method can give a rough estimate of age of subject in forensic samples that carry no morphological information.Methods DNA was extracted from sample of intramuscular and dermal, using proteinase K digest the sample, each sample was extracted twice with the phenol/chloroform, the oligonucleotide (CCCTAA)3 probe was labeled with digoxin(DlG) and decided it's best working concentration, DNA was digested with the restriction enzyme Hinf 1 , then DNA fragment was separated by agrose gel electrophoresis and transferred to a nylon membrane by vacuum blotter, the membrane was hybridized with the telomeric probe, stained with BCIP/NBT, analyzed by using a densitometric imaging system and mean length of TRF calculated.Results The relation of TRF and age was anal yzed by regression analysis, and the regression equation can be included in the following formula:Y(1)=53.302.1/X+6.069 Y(2)=54.147.1/X+6.047[Y: age (year),X: TRF(kb). (1) dermal, (2) intramuscular.] T-test result: There is a significant difference existed (p<0.05) in different gender, the TRF of female is longer than that of male. To the different territory, TRF is not a significant difference (P>0. 05) between the human of SHANXI and that of BEIJING. There is not a significant difference (P>0. 05) for estimating of age between the TRF of intramuscular and that of dermal.Conclusion The gradual shortening of TRF in dermal and intramuscular cells of human has a obvious correlation with the age, it has a fast shorten in the adolescent, and then it has a relative slower shorten in the adult. The TRF of female is longer than that of male to the same age. To the human of SHANGXI and BFIJING, there is not an obvious difference to the TRF. When the TRF of intramuscular is used for estimating age of human, the result is as good as that of dermal.