Genetic markers in semen. III: Alteration of phosphoglucomutase isozyme patterns in semen contaminated with saliva

Contamination of semen by saliva can result in the alteration of seminal phosphoglucomutase (PGM1) isozyme patterns. The alteration is characterized by the gradual loss of the a and b isozyme bands the concomitant generation of anodal bands; eventually, all PGM activity is lost. The conversion of PGM isozyme patterns has been shown to be due to a dialyzable heat-labile factor in saliva and a nondialyzable heat-labile factor in semen. The implications of this conversion for PGM typing in sexual assault evidence are discussed.     

Examination of the correlation of groupings in blood and semen

The grouping of blood/saliva samples from a male so as to predict his semen groups is only justified if there is a strict correlation between the groupings in these body fluids. This correlation has been examined in the ABO, phosphoglucomutase (PGM1) and glyoxalase I (GLO) grouping systems in blood and semen samples collected from more than 250 individuals. Though no results proved inconsistent with this correlation, a number of semen gave inconclusive grouping results. Reasons for this are discussed as well as the relevance of the results to semen stain analysis. Semen amylase activities are also reported.     

A sandwich enzyme-linked immunosorbent assay for ABO blood typing of semen by using anti-p 84 monoclonal antibody as a marker of blood group substance in semen

A blood group substance (BGS), a protein with ABH antigenic activity, was isolated from human seminal plasma and designated as p 84 (Sato, 1995). We have developed a method for determining the ABO blood type of semen by performing a sandwich enzyme-linked immunosorbent assay (ELISA) in which p 84 is captured with an anti-p 84 monoclonal antibody, and evaluated the specificity and sensitivity of this method. Although BGS activity was detected in semen sensitively by this method, it was not detected in saliva, urine, breast milk, blood or vaginal secretions. Since the concentration of p 84 in semen was independent of the secretion status, the status can be determined as non-secretor when p 84 but not BGS activity was detected. To determine the stability of BGS activity on p 84, dried stains of semen on filter paper were kept at 4, 26, and 37 degrees C for 8 months, 2 years and 1 month, respectively, and their BGS activities were examined. After 8 months at 4 degrees C, over 60% of the original BGS activity was recovered from the stain. The activity could be detected even from a square as small as 0.25 by 0.25 cm. After 1 month at 37 degrees C and 2 years at 26 degrees C, 31 and 20% of the BGS activity, respectively, still remained. It could be detected from the pieces of 1.0 by 1.0 cm and 0.5 by 0.5 cm squares, kept for 1 month at 37 degrees C and 2 years at 26 degrees C, respectively. Finally, semen was mixed with saliva or blood at varying volumetric ratios and used for the sources of dried stains. The BGS activity of p 84 could be detected in the stains until the ratio between semen and saliva or blood reached 1:4. We conclude that this sandwich ELISA offers a more sensitive and specific method for determining the ABO blood type of semen samples obtained from sexual assault victims than existing methods, such as the conventional absorption-elution and classical hemagglutination-inhibition tests.     

Amylase levels in semen and saliva stains

Amylase levels were determined for 148 semen samples and 20 saliva samples as well as for their corresponding stains. The effect of aging on the detectability of amylase activity in these stains was also investigated. The Phadebas amylase test was used for the quantitative assay of amylase. High levels of amylase in fluid saliva resulted in high levels being detected in saliva stains. Lower levels present in most seminal fluids produce little or no detectable amounts of amylase in stains. Interpretations are made as to the possible sources of amylase activity found in stains from laboratory casework based on both the amylase concentration and the elapsed time between collection and analysis. The evidential value of the presence or absence of amylase activity in casework stains is also discussed.     

Radioimmunoassay detection limits for 19-OH F1 alpha/F2 alpha prostaglandin in normal, infertile and vasectomized semen stains. Analysis of saliva, sweat and urine for possible non-specific or matrix effects

The sensitivity of a simple radioimmunoassay (RIA) for the detection of 19-OH prostaglandin F1 alpha/F2 alpha (PG F) has been evaluated on a number of semen samples from vasectomized, infertile and fertile donors. The specificity of the test has been examined by testing saliva, sweat and urine from a number of male and female donors. The assay technique could readily detect the PG in semen stains prepared from 0.2 microliter of semen from normal, infertile and vasectomized donors. The detection limit of the assay system, based on the observed displacement, was calculated to be approximately 0.05 microliter semen. The assay could be conducted over a pH range of 7.5-10.5 even after the PG has been heated to 100 degrees C. The 19-OH series of PG were absent from sweat, saliva and female urine using the normal assay protocol; volumes in excess of 100 microliters of some urines particularly from women in labour and those with acute urinary tract infection showed some displacement. Low levels of PG were detected in 50% of the male urine analysed. However, urine samples from men who had engaged in recent sexual activity contained relatively high concentrations of PG which could be readily detected in 10 microliters of urine. These results emphasise the potential of these compounds as specific and sensitive markers for the presence of human semen.     

A dot-blot-immunoassay for semen identification using a polyclonal antibody against semenogelin, a powerful seminal marker

Among various seminal plasma proteins, semenogelin (Sg), produced in the seminal vesicle, has been considered a candidate for demonstrating the presence of semen. Sg consists of two proteins, one 52 kDa (Sg-I) in size, and the other a mixture of 71 and 76 kDa proteins (Sg-II). Recombinant Sg-I and Sg-II proteins were obtained using a baculovirus system and then injected into a rabbit to produce the respective antibodies [Characterization of recombinant precursor proteins of the human seminal plasma sperm motility inhibitor synthesized in insect cells, Int. J. Mol. Med. 2 (1998) 693]. When liquefied seminal plasma was immunoblotted with the anti-Sg-I and Sg-II antibodies, the anti-Sg-II antibody identified a wider range of the polypeptides originating from Sg than did the anti-Sg-I antibody. A dot-blot-immunoassay using anti-Sg-II antibody revealed a clear immunoreactive spot even when the semen was diluted 6400-fold. However, this assay showed that the Sg antigen was undetectable in saliva, urine, vaginal secretions, sweat, nasal secretions and serum. To determine the stability of Sg antigenic activity, filter paper with dried semen stains were kept at 37, 4 and 22 degrees C for 1, 6 and 18 months, respectively, and the Sg antigenic activity was examined. The activity was detectable in an area not less than 0.5 cm x 0.5 cm under all of the above environmental conditions during each period. Finally, semen was mixed with saliva or blood at various volumetric ratios, and used as a source of dried stains. The Sg antigenic activity was detectable in the stains until the ratio of semen to saliva or blood reached 1:8. These results suggest that Sg may be useful as a marker for semen identification.     

Detection of amphetamine in bloodstains,semen, seminal stains,saliva, and saliva stains

Low nanogram quantities of amphetamine were detected in 100μl samples of dried bloodstains using radioimmunoassay. Saliva, saliva stains, semen, and seminal stains also contained measurable quantities of the drug.     

Secreted blood group substances: distributions in semen and stabilities in dried semen stains

A sensitive microplate hemagglutination-inhibition technique has been used to ascertain the distributions of secreted blood group substances (BGS) in a population of 176 semen specimens and to characterize the stability of these substances in dried semen stains. The BGS concentrations in semen were found to vary throughout a wide range of titer. Despite this latitude of variation, the titers for the component BGS within the blood groups could be described by a log-normal distribution function. Studies of a number of sequential semen specimens obtained from the same donors revealed that the intraindividual variation in BGS titers was much more limited than the interindividual BGS titers. Attempts to correlate variations in titers between A and H in Group A semen or B and H in Group B semen indicated that the levels of these component substances vary independently. Studies of the stability of BGS in Groups A and O semen suggested that these substances were stable when the semen stains were stored at -20 degrees C, 4 degrees C, or at ambient laboratory temperature in a dry state. In contrast, stains stored at 37 degrees C under humid conditions suffered a dramatic loss in BGS titer, with the half-life of the BGS being on the order of 30 days.     

Simultaneous identification of alpha-L-fucosidase and phosphoglucomutase (PGM) subtyping in semen stains

Seminal fluid and stains were analyzed by isoelectric focusing to determine the donor phenotype in the alpha-L-fucosidase (AlFuc) polymorphic system. The enzyme is found in both seminal fluid and spermatazoa. Three common phenotypes exist and can be identified in fluid specimens stored at 4 degrees C for more than a year. Untreated semen specimens display more than eight distinct bands of alpha-L-fucosidase activity with isoelectric points of pH 6.6 and below. Neuraminidase-treated specimens have enhanced banding patterns cathodally with a loss of activity in anodal bands making it easier to phenotype specimens. Semen stains maintained in dehumidified chambers at 25 or 37 degrees C retained activity for at least one month and could be accurately phenotyped. Activity was observed in semen specimens maintained at -20 degrees C in the dried state for a period of one year, whereas a complete loss of activity was observed after two weeks in similar specimens maintained at 25 or 37 degrees C under humid conditions. Of seventy-four semen stains analyzed, two had no apparent activity. Of the remaining seventy-two specimens 56, 32, and 12% were phenotyped as FUC 1-1, FUC 2-1, and FUC 2-2, respectively. Calculated gene frequencies are FUC1 = 0.72 and FUC2 = 0.28. Following analysis of alpha-L-fucosidase, the agarose gel can be chemically developed to reveal the PGM1 subtyping pattern. The ability to phenotype both systems in semen stains significantly improves the ability of the analyst to individualize this type of physical evidence. The probability of discrimination for these two combined systems is approximately 0.89.     

Use of the "SMITEST" PSA card to identify the presence of prostate-specific antigen in semen and male urine

To determine whether the prostate-specific antigen (PSA) could be identified in semen using the "SMITEST" PSA immunochromatographic membrane test card, we examined semen and other body fluids, including urine. Although PSA activity was detected in semen with high sensitivity using the "SMITEST" PSA card, it was also detected in adult male urine. However, the lower detectable limit in the urine was 1000-fold lower than that in semen. The concentration of PSA in adult male urine was found to be 800 ng/ml using the card. PSA activity usually can be detected in urine of individuals over 14 years old and it has been detected in urine from children as young as 11 years old. Therefore, the appearance of PSA in urine may occur anytime between the age of 12 and 14 years. To determine the stability of PSA activity in urine, dried samples of urine on filter paper were kept at room temperature for up to 3 years. Although the immunoreactive line showing PSA activity became weak after storage, it was still detectable, but faint, after 3 years. In addition, PSA activity was not detected in male serum or saliva and in the urine from human females, male cats or male dogs using the PSA card. We conclude that the PSA card is useful for identification of PSA in both semen and adult male urine.     

The detection of soluble ABH blood group substances in semen and saliva using monoclonal blood grouping reagents

Using an enzyme-linked immunosorbent assay (ELISA), this study investigated the use of monoclonal antibodies for detecting secreted ABH blood group substances in semen and saliva. The results demonstrated that the behavior of some monoclonals were unpredictable and often failed to detect the corresponding antigen in a number of the specimens tested. The suitability of the monoclonal reagents for detecting soluble blood group antigens could not be predicted by their behavior with red cell antigens. Consequently, care must be taken in the selection of monoclonal reagents for use in the detection of secreted blood group antigens.     

Detection of orosomucoid 1 phenotypes in semen and semen stains

Orosomucoid 1 phenotypes were detected in seminal plasma by isoelectric focusing and immunoprinting. The orosomucoid 1 phenotypes in seminal plasma correlated with the types found in the corresponding serum specimens. Semen stains stored for ten days could be typed for orosomucoid 1. The present work revealed that orosomucoid 1 is a useful genetic marker for the medicolegal grouping of semen stains.     

Identification of human semenogelin in membrane strip test as an alternative method for the detection of semen

Semenogelin (Sg), a protein originating in the seminal vesicles and a substrate for prostate specific antigen (PSA or p30), is a useful marker for the identification of semen. And detection of Sg has been available commercially in a membrane test recently. PSA is commonly used to detect semen in forensic significant samples taken from sexual assault cases. The strip PSA test has been available commercially from various manufacturers for many years. In this study, we evaluated two immunochromatographic membrane tests, one for Sg and the other for PSA by analyzing human semen, other human bodily fluids/materials including urine, blood, saliva, sweat, breast milk, vaginal secretion and fecal materials, semen from various animals and forensic casework samples. The data demonstrate that both Sg and PSA strip tests provide rapid and sensitive method for identification of seminal plasma. These results show that the immunochromatographic method for Sg detection is useful for the identification of seminal plasma in forensic samples, an alternative to the method for PSA detection.     

Evaluation of the 190H analogues of prostaglandins E1, E2, F1 alpha and F2 alpha as specific markers for the identification of human semen in body fluid mixtures

The specificity of antisera raised against each of the prostaglandin series 190H E1/E2 and 190H F1 alpha/F2 alpha, produced in males, was evaluated by radioimmunoassay. Further, the ability of these antisera to detect semen specific prostaglandins in mixtures of body fluids was examined. Antisera directed against the 190H E1/E2 series cross-reacted with prostaglandin E1 and marginally with E2. Antisera raised to the 190H F1 alpha/F2 alpha series were, however, highly specific to the semen specific prostaglandins 190H F1 alpha/F2 alpha and 190H E1/E2. It was possible to detect picogramme quantities of contaminating 190H F1 alpha/F2 alpha on vaginal swabs taken up to 72 h after intercourse and on vaginal swabs stored at room temperature for up to 2 years. These prostaglandins were not detected on semen free vaginal swabs, in faecal material, saliva, urine or in a sample of human milk (stain). A limited study of casework material is also described. Detection of the 190H F series, as a group, has considerable potential in the identification of human semen at picogramme levels, eliminating the need for alternative chemical tests and extensive microscopic examination.     

Studies on glyoxalase 1 isoenzymes in semen stains: polymorphism in Himachal (India) population

One hundred and ten pairs of blood and semen samples and their stains were studied to type glyoxalase 1 (GLO 1) isoenzymes using agarose-starch medium. A good agreement was observed between the phenotypes expressed in blood and semen samples of the same donor. No GLO 1 activity however could be demonstrated in the vaginal swabs tested. The gene frequencies of GLO 1 polymorphs in Himachal population has been worked out and their stability studies carried out at -12 degrees C and at room temperature.     

mRNA荧光复合扩增系统鉴别正常和异常精液初探

目的构建mRNA荧光复合扩增体系,实现对不同种类精液(尤其是无精症精液)的区分鉴别。方法收集正常、少精症及无精症的精液样本,制备精斑样本后提取细胞总RNA,利用逆转录PCR技术扩增2个精子特异mRNA标记(PRM1、PRM2)、2个精浆特异mRNA标记(TGM4、SEMG1)和2个管家基因mRNA标记(TEF、UCE)。结果正常精液样本可检测到全部精液mRNA标记表达;少精症精液样本虽然可检测到全部mRNA标记表达,但精子特异mRNA标记表达量较低;无精症精液样本不能检测到精子mRNA标记,只能检测到精浆特异mRNA标记。结论利用mRNA荧光复合扩增系统可以实现对正常和无精症精液的区分,而正常精液和少精症精液相比差异无统计学意义。     

STR and Y-STR genotyping of 30–50-year-old semen stains

This study performed the semen discrimination test, short tandem repeat (STR) typing, and Y-chromosome specific-STR (Y-STR) typing on five, 30–50-year-old semen stains. All samples reacted positively with the SM test reagent, and we observed sperm heads in all samples microscopically. The quantity of DNA extracted from the 43- and 50-year-old samples was much lower than from the other samples. STR typing of the 30-, 32-, 32-, 43-, and 50-year-old semen samples detected a maximum of 13, 15, 15, 11, and 6 of 15 loci, respectively, while Y-STR typing detected 16, 16, 16, 10, and 10 of 16 loci. These results suggest that the semen discrimination test and STR and Y-STR typing can detect extremely old semen stains and are useful for forensic practice.     

Results of the 2003-2004 GEP-ISFG collaborative study on mitochondrial DNA: focus on the mtDNA profile of a mixed semen-saliva stain

We report here a review of the seventh mitochondrial DNA (mtDNA) exercise undertaken by the Spanish and Portuguese working group (GEP) of the International Society for Forensic Genetics (ISFG) corresponding to the period 2003-2004. Five reference bloodstains from five donors (M1-M5), a mixed stain of saliva and semen (M6), and a hair sample (M7) were submitted to each participating laboratory for nuclear DNA (nDNA; autosomal STR and Y-STR) and mtDNA analysis. Laboratories were asked to investigate the contributors of samples M6 and M7 among the reference donors (M1-M5). A total of 34 laboratories reported total or partial mtDNA sequence data from both, the reference bloodstains (M1-M5) and the hair sample (M7) concluding a match between mtDNA profiles of M5 and M7. Autosomal STR and Y-STR profiling was the preferred strategy to investigate the contributors of the semen/saliva mixture (M6). Nuclear DNA profiles were consistent with a mixture of saliva from the donor (female) of M4 and semen from donor M5, being the semen (XY) profile the dominant component of the mixture. Strikingly, and in contradiction to the nuclear DNA analysis, mtDNA sequencing results yield a more simple result: only the saliva contribution (M4) was detected, either after preferential lysis or after complete DNA digestion. Some labs provided with several explanations for this finding and carried out additional experiments to explain this apparent contradictory result. The results pointed to the existence of different relative amounts of nuclear and mtDNAs in saliva and semen. We conclude that this circumstance could strongly influence the interpretation of the mtDNA evidence in unbalanced mixtures and in consequence lead to false exclusions. During the GEP-ISFG annual conference a validation study was planned to progress in the interpretation of mtDNA from different mixtures.     

Individual assignment of body fluids in mixed stains by synonymous SNP analysis

Genotyping of transcribed single nucleotide polymorphisms (SNPs) in cDNA molecules derived from tissue-specific mRNAs has a potential for linking cell types to donors in mixed stains. To test this hypothesis, a single base extension assay targeting the synonymous SNP marker rs857870 in the myeloid cell nuclear differentiation antigen (MNDA) gene was designed. In blood/semen mixtures from donors with informative MNDA genotype (opposite homozygotes), only the MNDA allele of the blood contributor was observed in cDNA, even at blood/semen ratios of 1/20, corresponding to the limit of detection for mixtures by STR profiling. In blood/saliva mixtures, the MNDA allele of the saliva donor was sporadically seen in cDNA, probably due to trace amounts of blood in the donor's saliva, suggesting that the informativeness of the assay may be limited in presence of cell types with partially overlapping mRNA profiles.