19th century family saga re-told by DNA recovered from postcard stamps.

Old postcards with stamps might help unravelling historical family stories and relationships. By employing ancient DNA recovered from world war I postage stamps, we disprove a family saga of an illegitimate child born in 1887. We developed a protocol to collect DNA from saliva, trapped and protected on the backside of postage stamps glued on postcards. With replicate STR analyses we were able to assemble almost full autosomal and Y-STR profiles of three male, deceased family members. The illegitimate child turned out to be a legitimate child of a later married couple.

A Swiss collaborative exercise for Disaster Victim Identification (DVI): Covering situations with different levels of complexity.

The identification of victims of a disaster (DVI) requires the collaboration of different specialists. Within a DVI context, DNA analyses often play an important role. Consequently, forensic genetic laboratories should be prepared to cope with DVI situations, as this can involve large-scale DNA profile comparisons. Six forensic genetic laboratories from Switzerland participated in an exercise where supposedly a plane had crashed. The goal of the exercise was to monitor participants use of dedicated software with ground truth cases and to make them aware of the existence of particular situations that may occur in real cases. For assigning the value of the comparison of the DNA profiles, all participating laboratories used the DVI module of Familias v3.2.1 In addition, one of the 6 laboratories used the Pedigree Searcher from CODIS v7.0. The data (AmpFlSTR® NGM SElect™ profiles) were generated to challenge the participating laboratories: cases with first, second degree biological parents, mutation events, as well as non-paternity cases were included. This study shows that the majority of the participants used the software in an appropriate way. However, a few misleading conclusions were detected for the most challenging situations. These errors belonged to one of the following categories: false pedigree, false association using the higher LR, misleading contextual information (false paternity) and not clustering family members. Specific recommendations are provided in order to reduce misuse of the software and the risk of misinterpretations by using all the relevant information.

Beyond simple kinship and identification: aDNA analyses from a 17th-19th century crypt in Germany.

Ancient DNA (aDNA) analysis is a powerful tool in multidisciplinary research on human remains, potentially leading to kinship scenarios and historical identifications. In this study, we present a genetic investigation of three noble families from the 17th to 19th centuries AD entombed in burial crypts at the cloister church of Riesa (Germany). Tests were aimed at identifying anticipated and incidental genetic relationships in our sample and the implications thereof for the assumed identity of the deceased. A total of 17 individuals were investigated via morphological, radiographic and aDNA analysis, yielding complete and partial autosomal and Y-STR profiles and reliable mtDNA sequences. Biostatistics and lineage markers revealed the presence of first to third degree relationships within the cohort. The pedigrees of the families Hanisch/von Odeleben and von Welck were thereby successfully reproduced, while four previously unknown individuals could be linked to the von Felgenhauer family. However, limitations of biostatistical kinship analysis became evident when the kinship scenario went beyond simple relationships. A combined analysis with archaeological data and historical records resulted in (almost) unambiguous identification of 14 of the 17 individuals.

Differential DNA extraction of challenging simulated sexual-assault samples: a Swiss collaborative study.

In sexual-assault cases, autosomal DNA analysis of gynecological swabs is a challenge, as the presence of a large quantity of female material may prevent detection of the male DNA. A solution to this problem is differential DNA extraction, but there is no established best practice for this. We decided to test the efficacy of a number of different protocols on simulated casework samples. Four difficult samples were sent to the nine Swiss laboratories active in forensic genetics. In each laboratory, staff used their routine protocols to separate the epithelial-cell fraction, enriched with the non-sperm DNA, from the sperm fraction. DNA extracts were then sent to the organizing laboratory for analysis. Estimates of male:female DNA ratio without differential DNA extraction ranged from 1:38 to 1:339, depending on the semen used to prepare the samples. After differential DNA extraction, most of the ratios ranged from 1:12 to 9:1, allowing detection of the male DNA. Compared with direct DNA extraction, cell separation resulted in losses of 94-98% of the male DNA. As expected, more male DNA was generally present in the sperm than in the epithelial-cell fraction. However, for about 30% of the samples, the reverse trend was seen. The recovery of male and female DNA was highly variable, depending on the laboratory involved. An experimental design similar to the one used in this study may be of assistance for local protocol testing and improvement.

Bunched, the Drosophila homolog of the mammalian tumor suppressor TSC-22, promotes cellular growth.

BACKGROUND: Transforming Growth Factor-beta1 stimulated clone-22 (TSC-22) is assumed to act as a negative growth regulator and tumor suppressor. TSC-22 belongs to a family of putative transcription factors encoded by four distinct loci in mammals. Possible redundancy among the members of the TSC-22/Dip/Bun protein family complicates a genetic analysis. In Drosophila, all proteins homologous to the TSC-22/Dip/Bun family members are derived from a single locus called bunched (bun). RESULTS: We have identified bun in an unbiased genetic screen for growth regulators in Drosophila. Rather unexpectedly, bun mutations result in a growth deficit. Under standard conditions, only the long protein isoform BunA - but not the short isoforms BunB and BunC - is essential and affects growth. Whereas reducing bunA function diminishes cell number and cell size, overexpression of the short isoforms BunB and BunC antagonizes bunA function. CONCLUSION: Our findings establish a growth-promoting function of Drosophila BunA. Since the published studies on mammalian systems have largely neglected the long TSC-22 protein version, we hypothesize that the long TSC-22 protein is a functional homolog of BunA in growth regulation, and that it is antagonized by the short TSC-22 protein.