Fusion transcripts involving HMGA2 are not a common molecular mechanism in uterine leiomyomata with rearrangements in 12q15.

Uterine leiomyomata are one of several benign tumors characterized by frequent chromosomal rearrangement involving 12q15. The 12q15 rearrangement in leiomyomata typically is manifested as t(12;14)(q15;q23-24), which has been hypothesized to create pathobiologically significant fusion transcripts derived from HMGA2 and RAD51L1. To explore further this hypothesis, we mapped chromosomal breakpoints in 38 uterine leiomyomata with rearrangements involving 12q15 using fluorescence in situ hybridization. Most tumors (n = 26) harbored der(14)t(12;14)(q15;q23-24), whereas chromosomes 1, 5, 8, and 10 were involved in rearrangements with 12q15 in six myomas. An additional six cases had more complex rearrangements, including breakpoints other than 12q15 or 14q23-24, inversions of chromosome 12, insertions of 12q15 into chromosome 14, or additional translocation partners. Breakpoints were mapped either 5' (centromeric) or 3' (telomeric) in the HMGA2 locus in 24 and nine cases, respectively; one tumor was a mosaic of cells with either 5' or 3' breakpoints. Breakpoints flanking the gene in both 5' and 3' regions were found in six cases. Analysis of one tumor by 3' rapid amplification of cDNA ends showed altered transcripts in which either exons 1-3 of HMGA2 were aberrantly spliced to cryptic sites in chromosome 12 or transcripts encompassing the full coding sequence of HMGA2 through a portion of the 3' untranslated region were fused to sequence from chromosome 14. A panel of 10 uterine leiomyomata with t(12;14) was specifically tested for fusion transcripts. RAD51L1-HMGA2 transcripts were not detected. HMGA2-RAD51L1 transcripts, however, were detected in four tumors; two of these tumors had uncommon rearrangements in the 3' region of HMGA2 and two had 5' rearrangements. Although the mechanism of fusion transcripts derived from tumors with 5' breakpoints is unclear, these findings indicate that formation of a fusion transcript is not the principle pathobiological mechanism in uterine leiomyomata. The pattern of rearrangements suggests dysregulated expression of HMGA2, most often by translocation of chromosome 14 sequence 5' to this gene.

Validation of male-specific, 12-locus fluorescent short tandem repeat (STR) multiplex.

Y chromosome-specific short tandem repeat (Y-STR) analysis has become another widely accepted tool for human identification. The PowerPlex Y System is a fluorescent multiplex that includes the 12 loci: DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439. This panel of markers incorporates the 9-locus European minimal haplotype (EMH) loci recommended by the International Y-STR User Group and the 11-locus set recommended by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Described here are inter-laboratory results from 17 developmental validation studies of the PowerPlex Y System and include the following results: (a) samples distributed between laboratories and commercial standards produced expected and reproducible haplotypes; (b) use of common amplification and detection instruments were successfully demonstrated; (c) full profiles were obtained with standard 30 and 32 cycle amplification protocols and cycle number (24-28 cycles) could be modified to match different substrates (such as direct amplification of FTA paper); (d) complete profiles were observed with reaction volumes from 6.25 to 50 microL; (e) minimal impact was observed with variation of enzyme concentration; (f) full haplotypes were observed with 0.5-2x primer concentrations; however, relative yield between loci varied with concentration; (g) reduction of magnesium to 1mM (1.5 mM standard) resulted in minimal amplification, while only partial loss of yield was observed with 1.25 mM magnesium; (h) decreasing the annealing temperature by 2-4 degrees C did not generate artifacts or locus dropout and most laboratories observed full amplification with the annealing temperature increased by 2 degrees C and significant locus dropout with a 4 degrees C increase in annealing temperature; (i) amplification of individual loci with primers used in the multiplex produced the same alleles as observed with the multiplex amplification; (j) all laboratories observed full amplification with >or = 125 pg of male template with partial and/or complete profiles observed using 30-62.5 pg of DNA; (k) analysis of < or = 500 ng of female DNA did not yield amplification products; (l) the minor male component of a male/female mixture was observed with < or =1200-fold excess female DNA with the majority of alleles still observed with 10,000-fold excess female; (m) male/male mixtures produced full profiles from the minor contributor with 10-20-fold excess of the major contributor; (n) average stutter for each locus; (o) precision of sizing were determined; (p) human-specificity studies displayed amplification products only with some primate samples; and (q) reanalysis of 102 non-probative casework samples from 65 cases produced results consistent with original findings and in some instances additional identification of a minor male contributor to a male/female mixture was obtained. In general, the PowerPlex Y System was shown to have the sensitivity, specificity and reliability required for forensic DNA analysis.

Validation of a male-specific, 12-locus fluorescent short tandem repeat (STR) multiplex.

Y chromosome-specific short tandem repeat (Y-STR) analysis has become another widely accepted tool for human identification. The PowerPlex Y System is a fluorescent multiplex that includes the 12 loci: DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439. This panel of markers incorporates the 9-locus European minimal haplotype (EMH) loci recommended by the International Y-STR User Group and the 11-locus set recommended by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Described here are inter-laboratory results from 17 developmental validation studies of the PowerPlex Y System and include the following results: (a) samples distributed between laboratories and commercial standards produced expected and reproducible haplotypes; (b) use of common amplification and detection instruments were successfully demonstrated; (c) full profiles were obtained with standard 30 and 32 cycle amplification protocols and cycle number (24-28 cycles) could be modified to match different substrates (such as direct amplification of FTA paper); (d) complete profiles were observed with reaction volumes from 6.25 to 50 microL; (e) minimal impact was observed with variation of enzyme concentration; (f) full haplotypes were observed with 0.5-2x primer concentrations; however, relative yield between loci varied with concentration; (g) reduction of magnesium to 1mM (1.5 mM standard) resulted in minimal amplification, while only partial loss of yield was observed with 1.25 mM magnesium; (h) decreasing the annealing temperature by 2-4 degrees C did not generate artifacts or locus dropout and most laboratories observed full amplification with the annealing temperature increased by 2 degrees C and significant locus dropout with a 4 degrees C increase in annealing temperature; (i) amplification of individual loci with primers used in the multiplex produced the same alleles as observed with the multiplex amplification; (j) all laboratories observed full amplification with >or = 125 pg of male template with partial and/or complete profiles observed using 30-62.5 pg of DNA; (k) analysis of < or = 500 ng of female DNA did not yield amplification products; (l) the minor male component of a male/female mixture was observed with < or =1200-fold excess female DNA with the majority of alleles still observed with 10,000-fold excess female; (m) male/male mixtures produced full profiles from the minor contributor with 10-20-fold excess of the major contributor; (n) average stutter for each locus; (o) precision of sizing were determined; (p) human-specificity studies displayed amplification products only with some primate samples; and (q) reanalysis of 102 non-probative casework samples from 65 cases produced results consistent with original findings and in some instances additional identification of a minor male contributor to a male/female mixture was obtained. In general, the PowerPlex Y System was shown to have the sensitivity, specificity and reliability required for forensic DNA analysis.

Twelve short tandem repeat loci Y chromosome haplotypes: genetic analysis on populations residing in North America.

A total of 2443 male individuals, previously typed for the 13 CODIS STR loci, distributed across the five North American population groups African American, Asian, Caucasian, Hispanic, and Native American were typed for the Y-STR loci DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 using the PowerPlex Y System. All population samples were highly polymorphic for the 12 Y-STR loci with the marker DYS385a/b being the most polymorphic across all sample populations. The Native American population groups demonstrated the lowest genetic diversity, most notably at the DYS393 and DYS437 loci. Almost all of the 12-locus haplotypes observed in the sample populations were represented only once in the database. Haplotype diversities were greater than 99.6% for the African Americans, Caucasians, Hispanics, and Asians. The Native Americans had the lowest haplotype diversities (Apaches, 97.0%; Navajo, 98.1%). Population substructure effects were greater for Y-haplotypes, compared with that for the autosomal loci. For the apportionment of variance for the 12 Y-STRs, the within sample population variation was the largest component (>98% for each major population group and approximately 97% in Native Americans), and the variance component contributed by the major population groups was less than the individual component, but much greater than among sample populations within a major group (11.79% versus 1.02% for African Americans/Caucasians/Hispanics and 15.35% versus 1.25% for all five major populations). When each major population is analyzed individually, the R(ST) values were low but showed significant among group heterogeneity. In 692 confirmed father-son pairs, 14 mutation events were observed with the average rate of 1.57x10(-3)/locus/generation (a 95% confidence bound of 0.83x10(-3) to 2.69x10(-3)). Since the Y-STR loci reside on the non-recombining region of the Y chromosome, the counting method is one approach suggested for conveying an estimate of the rarity of the Y-haplotype. Because the Y-STR loci are not all in disequilibrium to the same extent, the counting method is a very conservative approach. The data also support that autosomal STR frequencies can be multiplied by the upper bound frequency estimate of a Y-haplotype in the individual population group or those pooled into major population groups (i.e., Caucasian, African American, Hispanic, and Asian). These analyses support use of the haplotype population data for estimating Y-STR profile frequencies for populations residing in North America.

A simple DNA extraction method for marijuana samples used in amplified fragment length polymorphism (AFLP) analysis.

As a first step in developing a molecular method for the individualization of marijuana samples, we evaluated a plant DNA extraction kit. The QIAGEN plant DNeasy method uses a spin column format for recovery of DNA and is effective for obtaining high molecular weight DNA from leaf, flower (bud), and seed samples of marijuana. The average DNA yield was 125-500 ng per 100 milligrams of fresh plant tissue. The recovered DNA was of polymerase chain reaction (PCR) quality as measured by the ability to generate reproducible amplified fragment length polymorphism (AFLP) profiles. AFLP is a technique used to create a DNA profile for plant varieties and is being applied to marijuana samples by the authors to link growers and distributors of clonal material. The QIAGEN plant DNeasy method was simple, efficient, and reproducible for processing small quantities of marijuana into DNA.

DNA analysis of digested tomato seeds in stomach contents.

Examination of stomach contents is one of the important steps in medical legal autopsy. Vegetative materials such as stems, roots, and seeds in stomach contents can be valuable evidence for providing investigative leads in death investigation. Currently, the identification of plant materials relies on microscopic and morphologic examination. We have found that many seeds are often protected from acid degradation during stomach digestion by their tough exterior seed coat. Tomato seeds were selected as a model system to assess DNA analysis and plant variety marker identification. The DNA-amplified fragment length polymorphism method was performed to determine if the DNA obtained from single seeds could be used for PCR analysis. From the amplified fragment length polymorphism results, some candidate markers for individualizing seeds from morphologically distinct tomatoes were identified. These data on DNA analysis of tomato seeds indicate amplified fragment length polymorphism is a viable procedure for the individualization of seeds from stomach contents in forensic investigations.

An organizational model of transcription factor binding sites for a histone promoter in D. melanogaster.

The Drosophila H2A-H2B histone spacer, a small region that functions as a bidirectional promoter for the gene pair, was used as a test sequence for generation of a computationally derived organizational model of transcription factor (TF) binding sites. Expression studies of the spacer revealed that it contains the necessary sequences to confer replication-dependent transcription in partially synchronized cells in culture. Informatics analysis of the spacer uncovered a number of binding sites for specific TFs, none of which had been previously associated with this particular promoter. Each of the TFs in the promoter organizational model are also known to participate in stages of fly development that are characterized by DNA replication and/or cell division, thus providing a biologically functional rationale for an association. Moreover, phylogenetic analysis of the binding sites provides evidence for evolutionary conservation of the essential features of the organizational model. The model, if correct, provides information about the molecules that couple developmental specific demands and histone gene transcription.

An overview of DNA methods for the identification and individualization of marijuana.

The purpose of this review is to summarize the status of DNA-based methods for the identification and individualization of marijuana. In forensics, both identification of a substance as marijuana and the subsequent individualization of a sample may be desired for casework. Marijuana identification methods in the United States primarily include biochemical tests and, less frequently, DNA-based tests. Under special circumstances, DNA-based tests can be useful. For example, if the quantity of seized marijuana is extremely small and/or biochemical tests do not detect any D9-tetrahydrocannabinol (THC), DNA identification of plant material as Cannabis is still possible. This circumstance can arise when seeds, trace residue, tiny leaf fragments, or fine roots need to be analyzed. Methods for the individualization of marijuana include amplified fragment length polymorphism (AFLP), random amplified polymorphic DNA (RAPD), and short tandem repeat (STR) techniques that link an evidentiary sample to a source. Marijuana growers propagate their plants either by seed or by cloning. Seed-generated marijuana plants are expected to have unique DNA profiles analogous to a human population. Cloned marijuana plants, however, exhibit identical DNA profiles that allow for tracking of plant material derived from a common genetic lineage. The authors have validated the AFLP method for marijuana samples and are constructing a comparative database of marijuana seizure samples to estimate the expected frequency of a DNA profile match between unrelated plants. Continued development of DNA-based methods for plants can be useful for marijuana and other types of plant evidence in forensics.