Atsushi Ishiko

Estimating age of humans based on telomere shortening.

To estimate age using DNA based on telomere shortening, we determined the terminal restriction fragment (TRF) length, as telomere length, using Southern blot analysis of peripheral human blood and blood stains. All blood stains had been stored at room temperature for 5 months. The average TRF length clearly showed a tendency to shortening with aging. The formula for age estimation was based on a correlation between average TRF length and age of the subjects. The estimated age calculated from TRF length widely depends on environmental and genetic factors. However, as long as the DNA is well preserved, use of our method is feasible regardless of age of the subject and can give a rough estimation of age of subjects in forensic samples that carry no morphological information.

Unusual death of a baby: a dog attack and confirmation using human and canine STRs

We performed an autopsy on a 3-month-old baby boy who had only one area severe and extensive wound to his head and face. Three unrelated miniature dachshunds were in the house. After our investigation, we were able to confirm that the wound had in fact been caused by a dog attack, and we were able to identify the offending dog among the three dogs using both human and canine short tandem repeat obtained from samples taken from the suspected dog and from the scene of the attack.

Personal identification using Y-chromosomal short tandem repeats from bodily fluids mixed with semen.

The male-specific, human Y-chromosomal short tandem repeats (Y-STRs) are very useful in forensic analysis. The authors report a sexual crime case in which the direct Y-STR haplotype analysis of several mixtures of various bodily fluids including semen was very effective for identifying the perpetrator of the crime. The typing of three Y-STRs (DYS19, DYS389II, and DYS390) could be detected from the mixed DNA of sperm and female cells in the victim’s vagina, vaginal orifice, and anus. These haplotypes originated from one man and matched those of the suspect. Accordingly, the combination of direct extraction of DNA and Y-STR haplotype analysis is considered to be very useful for mixtures of bodily fluids, including semen or other male cells.

Kinship analysis using DNA typing from five skeletal remains with an unusual postmortem course

The skeletal remains of five individuals with an unusual postmortem course were discovered in a house. According to the explanation of the putative bereaved family, the postmortem interval of the five remains was between five and 20 years. They also explained to the police that they and the dead family members believed that the dead can be resurrected, and they had kept the bodies indoors, so the bodies had followed an unusual postmortem course. The five dead were identified by kinship analysis using DNA typing. For DNA extraction, we used the DNA extraction method with ultrafiltration and a silica-based DNA extraction kit. As a result, complete amplification STR profiles were obtained from DNA from bone samples of all five skeletons and their identity was proven by kinship testing.

Telomere Shortening and Age Estimation in Forensic Medicine

fi rst electrophoresis was of course done randomly. Regarding the fourth point, we used the same numbers for each age group as an ideal method; however, very young or very old healthy persons who gave their informed consent were few, consequently we used middle aged subjects. As to fi fth point, of course we occasionally detected the long telomere; however, we did not detect the very long telomeres. Mr. Lahnert’s method is also fundamentally a Southern blot method, and is not novel. Each lane is very long in his method, and it is considered that deciding where the start and end points in the smear are is diffi cult because of its length, although the smear was stained by color. A number of forensic scientists in our laboratory decided the start and end points of the smear; however, we recommend another method such as the hybridization protection assay which we mentioned in our paper [2] in place of the Southern blot method. Generally, the cell cannot divide when its telomere length becomes 5 kb. Therefore, scattering of the telomere length appears narrow in old persons. In our data, the Dear Dr. W. Meier-Ruge, Our purpose was a rough age estimation deduced from extracted human DNA. While age estimation is one most important in forensic medicine, it is sometimes diffi cult to obtain because decisive features can be absent in a cadaver. It is impossible for us to estimate age from specimens such as blood or other body fl uids, therefore ours is valuable information regarding DNA from young or middle-aged or older persons. Peter Lahnert asked about our paper titled ‘Estimating age of humans based on telomere shortening’. He asked fi rst in his Discussion, why the number of points are 48 rather than the 60 samples shown in our fi gure 2 . Some points looked like one because of an overlap. Secondly about the size marker, we did not notice the gap of the size position when we set up the fi gure 1 . The positions of 21226, 8576 and 7427 bp are correct and that of 4973 bp is much below. The correct positions of these bands were mentioned in our next paper [1] . The third suggestion is about the order of applied samples. Figure 1 was arranged in order of age and was the picture of re-electrophoresis for the contribution to the paper. The