RESUMEN
In the human skin, melanocytes are present in the epidermis and hair follicles. The basic features of these cells are the ability to melanin production and the origin from neural crest cells. This last element is important because there are other cells able to produce melanin but of different embryonic origin (pigmented epithelium of retina, some neurons, adipocytes). The life cycle of melanocyte consists of several steps including differentiation of melanocyte lineage/s from neural crest, migration and proliferation of melanoblasts, differentiation of melanoblasts into melanocytes, proliferation and maturation of melanocytes at the target places (activity of melanogenic enzymes, melanosome formation and transport to keratinocytes) and eventual cell death (hair melanocytes). Melanocytes of the epidermis and hair are cells sharing some common features but in general they form biologically different populations living in unique niches of the skin.
RESUMEN
The objective of the study was to examine the mutation rates of Y-chromosomal STR from father-son pairs. The paternity in these cases was confirmed previously with the use of autosomal STR system performing standard analyses of genetic profiles of the mother, child and putative father (PI > = 100000). We examined 200 father-son sample pairs from Northern Poland using the Y-STR 18-plex. We identified eleven mutations. Five mutations resulted in the gain of a repeat in the sons' chromosome and six resulted in a loss of a repeat. All the samples resulted in single repeat mutations from one sample, which contained a two repeat loss at DYS385. The overall average mutation rate estimate was 0.0031.There was no significant difference in the mutation rate between Y-STR loci of the 200 tested father-son pairs and the YHRD base.
