Characterization of 58 STRs and 94 SNPs with the ForenSeq™ DNA signature prep kit in Mexican-Mestizos from the Monterrey city (Northeast, Mexico).

BACKGROUND: STR allele frequency databases from populations are necessary to take full advantage of the increased power of discrimination offered by massively parallel sequencing (MPS) platforms. MATERIAL AND METHODS: For this reason, we sequenced 58 STRs (aSTRs, X-STRs, and Y-STRs) and 94 identity informative SNPs (iiSNPs) on 105 Mestizo (admixed) individuals from Monterrey City (Northeast, Mexico), with the Primer Set-A of the ForenSeq™ DNA Signature Prep Kit. RESULTS: Most of the STR markers were in Hardy Weinberg equilibrium, with a few exceptions. We found 346 different length-based alleles for these 58 STRs; nevertheless, they became 528 alleles when the sequence was assessed. The combined power of discrimination from autosomal STRs (aSTRs) was -virtually- 100% in both length and sequence-based alleles, while the power of exclusion was 99.9999999976065 and 99.9999999999494%, respectively. Haplotypes based on X-STRs and Y-STRs showed 100% of discriminatory capacity. CONCLUSIONS: These results provide -for the first time- forensic genomic population data from Mexico necessary for interpretation in kinship and criminal analyses.

Accuracy of Eye and Hair Color Prediction in Mexican Mestizos from Monterrey City Based on ForenSeqTM DNA Signature Prep.

Forensic genomic systems allow simultaneously analyzing identity informative (iiSNPs), ancestry informative (aiSNPs), and phenotype informative (piSNPs) genetic markers. Among these kits, the ForenSeq DNA Signature prep (Verogen) analyzes identity STRs and SNPs as well as 24 piSNPs from the HIrisPlex system to predict the hair and eye color. We report herein these 24 piSNPs in 88 samples from Monterrey City (Northeast, Mexico) based on the ForenSeq DNA Signature prep. Phenotypes were predicted by genotype results with both Universal Analysis Software (UAS) and the web tool of the Erasmus Medical Center (EMC). We observed predominantly brown eyes (96.5%) and black hair (75%) phenotypes, whereas blue eyes, and blond and red hair were not observed. Both UAS and EMC showed high performance in eye color prediction (p ≥ 96.6%), but a lower accuracy was observed for hair color prediction. Overall, UAS hair color predictions showed better performance and robustness than those obtained with the EMC web tool (when hair shade is excluded). Although we employed a threshold (p > 70%), we suggest using the EMC enhanced approach to avoid the exclusion of a high number of samples. Finally, although our results are helpful to employ these genomic tools to predict eye color, caution is suggested for hair color prediction in Latin American (admixed) populations such as those studied herein, principally when no black color is predicted.

Allele and haplotype frequencies of 12 X-STRs in Mexican population.

The use of X-chromosome short tandem repeats (X-STRs) to solve complex kinship cases has been facilitated by commercial human identification kits, such as the Argus X-12 kit (Qiagen), and the free-access software FamlinkX. For this purpose, allele and haplotype frequencies are required in the populations to be employed. Therefore, we obtained Argus X-12 haplotypes in 933 unrelated males from seven different geographic regions from Mexico. Forensic parameters for individual X-STRs and for three-loci linkage groups are reported. The observed homogeneity between the studied population samples support to use a global Mexican population database (Fst p-value >0.05). In brief, forensic validation of the Argus X-12 kit was performed to facilitate incorporation of X-STRs in forensic casework in this country.

Population data of 24 STRs in Mexican-Mestizo population from Monterrey, Nuevo Leon (Northeast, Mexico) based on Powerplex(®) Fusion and GlobalFiler(®) kits.

The STR loci included into new commercial human identification kits compels geneticists estimating forensic parameters for interpretation purposes in forensic casework. Therefore, we studied for the first time in Mexico the GlobalFiler(®) and Powerplex(®) Fusion systems in 326 and 682 unrelated individuals, respectively. These individuals are resident of the Monterrey City of the Nuevo Leon state (Northeast, Mexico). Population data from 23 autosomal STRs and the Y-STR locus DYS391 are reported and compared against available STR data from American ethnic groups and the unique Mexican population studied with Powerplex(®) Fusion.

Ultrastructural findings in semen samples of infertile men infected with Chlamydia trachomatis and mycoplasmas.

The aim of this study was to describe the ultrastructural features observed in semen samples of men with infertility and subfertility of unknown cause infected with Chlamydia trachomatis and mycoplasmas. The findings observed by ultrastructure included destruction or persistence of bacteria in leukocytes, phagocytosis of spermatozoa by leukocytes, and structural damage of spermatozoa.

Rat spermatogenesis damage in intermittent hypobaric hypoxia and the protective role of melatonin. II: testicular parameters / Daño de la espermatogénesis en rata en la hipoxia hipobárica intermitente y rol protector de la melatonina. II: parámetros testiculares

At present it is not clear if male fertility is affected by intermittent hypobaric hypoxia (IHH). This is an important issue since a large human population works over 3000 masl. This study analyzes testicular changes in adult Sprague Dawley rats after five cycles of IHH (7 day exposure to 4200 masl in a hypobaric chamber / 7 day at 500 masl). The animals were separated into groups of 8, one group was exposed to hypoxia (7 days), and the others to IHH for one to five cycles. Controls (500 masl) were examined at the beginning and at the end of the 70 experimental days. A duplicate set of rats treated with melatonin (supposedly protecting from hypoxia) was also examined, as were their controls, injected with 0,03 percent ethanol (melatonin solvent).Immunohistochemical and histometric analysis of testicular tissue were performed. Damage caused by IHH increases with time. Morphometry reveals an increase in tubular and luminal diameters and a reduction in epithelial height. Inmunohistochemistry for HIF-1alpha shows an increase with time, however the opposite happens with HSP-70. Spermatogenic cells submitted to comet assay present an increase of (+) cells. Melatonin counteracts all this damage, possibly due to its high efficiency as a reactive oxygen species scavenger. In conclusion, IHH exposure damages male reproductive function.

Actualmente no se conoce claramente si la fertilidad masculina se afecta por la hipoxia hipobarica intermitente (IHH). Esto es de importancia porque una gran población humana trabaja sobre 3000 metros sobre el nivel del mar (sml). Este trabajo analiza los cambios testiculares en ratas adultas Sprague Dawley luego de cinco ciclos de IHH (7 días a 4.200 sml) en una camara hipobarica/7días a 500 metros: Normoxia). Los animales de dividieron en grupos de 8; un grupo expuesto a hipoxia (7 días ) y los otros a IHH por uno y hasta cinco ciclos. Los controles ( 500 sml) se analizaron al inicio y al final de los 70 días experimentales. Un set duplicado de ratas tratadas con melatonina (considerada protectora de la Hipoxia) se examinó también, así como sus controles, inyectados con etanol 0,03 por ciento (solvente de la melatonina).Se realizó análisis histométrico e inmunohistoquímico del tejido testicular. El daño causado por IHH aumenta con el tiempo. La morfometría reveló un aumento de los diámetros del túbulo y lumen y una reducción de la altura del epitelio. La inmunohistoquímica de HIF-1 alpha muestra aumento del número de túbulos positivos con el tiempo aunque lo opuesto ocurre para HSP-70. El ensayo de cometa muestra un aumento del número de células espermátogénicas (+). La melatonina controla este daño, posiblemente debido a asu alta eficiencia como neutralizador de especies reactivas del oxígeno. En conclusión, la exposición a IHH daña la función reproductiva masculina.

Rat spermatogenesis damage in intermittent hypobaric hypoxia and the protective role of melatonin: I cauda epididymal spermatozoa / Daño en la espermatogénesis de rata en hipoxia hipobárica intermitente y el papel protector de la melatonina: I espermatozoides de la cauda epididimaria

At present it is not clear if male fertility is affected by intermittent hypobaric hypoxia (IHH). This is an important issue since a large human population works over 3000 masl. This study analyzes epididymal sperm, in adult Sprague Dawley rats after five cycles of IHH (7 days exposure to 4200 masl in a hypobaric chamber / 7 days at 500 masl). The animals were separated into groups of 8, one group was exposed to hypoxia (7 days), and the others to IHH for one to five cycles. Controls (500 masl) were examined at the beginning and at the end of the 70 experimental days. A duplicate set of rats treated with melatonin (supposedly protecting from hypoxia) was also examined, as were their controls, injected with 0,03 percent ethanol (melatonin solvent). Epididymal sperm parameters, were evaluated. Damage caused by IHH increases with time. Sperm counts drop, while sperm chromatin swelling, DNA instability (metachromasia with acridine orange epifluorescence) and comet (+) tests increase. Melatonin counteracts all this damage, possibly due to its high efficiency as a reactive oxygen species scavenger. In conclusion, IHH exposure damages sperm quality and therefore male reproductive function.

En la actualidad no está claro si la fertilidad masculina se ve afectada por la hipoxia hipobárica intermitente (HHI). Esta es una cuestión importante, ya que una gran población humana trabaja a más de 3000 metros sobre el nivel del mar (msnm). Este estudio analiza los espermatozoides del epidídimo, en ratas Sprague Dawley adultas, después de cinco ciclos de HHI (7 días de exposición a 4200 msnm en una cámara hipobárica / 7 días a 500 msnm). Los animales fueron separados en grupos de 8, un grupo fue expuesto a la hipoxia (7 días), y los otros a HHI de uno a cinco ciclos. Los controles (500 msnm) se examinaron al comienzo y al final de los 70 días de experimentación. Un grupo duplicado de ratas tratadas con melatonina (supuestamente protegiendo de la hipoxia) también fue examinado, al igual que los controles, inyectados con 0,03 por ciento de etanol (solvente de melatonina). Los parámetros espermáticos del epidídimo fueron evaluados. Los daños causados por la HHI aumentaron con el tiempo. Se evaluó el conteo espermático en gota, mientras la cromatina espermática esta hinchada, la inestabilidad del ADN (metacromasia epifluorescente con naranjo de acridina) y la prueba de aumento (+) de cometas. La melatonina neutralizó todo el daño, posiblemente debido a su alta eficacia como un eliminador de especies reactivas de oxígeno. En conclusión, la exposición a HHI daña la calidad espermática y por lo tanto la función reproductora masculina.