Environmental and Anthropogenic Influences on Coliform Concentrations in the Octopus insularis Production Chain in the Veracruz Reef System, Gulf of Mexico.

Coliforms are relatively common in aquatic environments, but their concentrations can be increased by environmental changes and anthropogenic activities, thus impacting fisheries resources. To determine the microbiological quality in the octopus production chain (capture, post-capture, processing and commercialization), total (TC) and fecal (FC) coliforms were quantified in sea water, fresh octopus, fresh water, ice and octopus in two presentations: packed in ice and boiled. Samples came from fishing zones Enmedio, Chopa and La Gallega at the Veracruz Reef System (VRS) during dry, rainy and windy seasons. The coliforms were determined using the most probable number technique (MPN). The most relevant results indicated that octopus packed in ice coming from the commercialization stage had FC levels >540 MPN/100 g, which exceeded the permissible limits (230 MPN/100 g). Therefore, these products present a risk for human consumption. Differences in FC were observed in octopuses between the three fishing zones (H = 8.697; p = 0.0129) and among the three climatic seasons, increasing during the rainy season, highlighting La Gallega with 203.33 ± 63 MPN (H = 7.200; p = 0.0273). The results provide evidence of the environmental and anthropogenic influences on coliform concentrations and the urgent need to implement an efficient cold chain throughout octopus production stages with adequate handling practices to reverse this situation.

Oocyte dynamics for Atlantic bluefin tuna (Thunnus thynnus) in the southern Gulf of Mexico: A comparative assessment of Mediterranean spawners using two stereological methods.

Although most research focused on the northern Gulf of Mexico for western Atlantic bluefin tuna, the histological records of reproductive activity of this species in the southern Gulf of Mexico (Mexican waters) have been presented for the first time. This work is the first to study oocyte dynamics in Atlantic bluefin tuna caught in the southern Gulf of Mexico by assessing and comparing them with Mediterranean stock (BFT-E) through stereology using two different methods. Regardless of Atlantic bluefin tuna females returning to their respective spawning grounds at different months in the southern Gulf of Mexico and the Mediterranean, both stocks arrived reproductively inactive and remained in these zones during periods of similar length; they were reproductively active until March for the southern Gulf of Mexico and May for the Mediterranean females. The comparison of the size structure between the two stocks examined using kernel density estimators demonstrated a quite remarkable difference in mean fork lengths between stocks. The ovarian oocyte density, that is, the number of oocytes per gram of ovary, for each gonad stage predicted using the Weibel and Gomez and oocyte packing density (OPD) methods did not significantly differ between stocks and showed that advanced vitellogenic oocytes from spawning-capable females are an appropriate indicator to estimate potential fecundity, presenting values of c. 1273 and ~1355 eggs per gram for the southern Gulf of Mexico and Mediterranean females, respectively. Females caught in Mexican waters (southern Gulf of Mexico) were larger than those caught in the Mediterranean; however, it was demonstrated that the length and weight of females did not affect ovarian oocyte density production. In addition, densities estimated for each gonad stage using W&G and OPD methods did not differ between stocks and presented equal patterns in their oocyte dynamics. These findings contribute to a better understanding of the reproductive biology of Atlantic bluefin tuna, especially in the southern Gulf of Mexico, due to the lack of information regarding this zone, and may allow to support strategies for proper assessment, management, and conservation.

Analysis of the TSER and G>C variants in the TYMS gene: a high frequency of low expression genotypes predicted in the Mexican population.

BACKGROUND: In the TYMS gene promoter, there is a repeat polymorphism (TSER) that affects the expression level of the thymidylate synthetase (TS) enzyme involved in the response to some anticancer drugs. The G>C transversion located in the TSER*3R allele decreases the expression level of the TS enzyme avoiding the upstream stimulatory factor (USF-1) binding site. Despite the biomedical impact of the SNP G>C, only TSER has been reported in most worldwide populations. Thus, we studied both TSER and SNP G>C variants in the Mexican population. SUBJECTS AND METHODS: A population sample (n = 156) was genotyped for the TSER and G>C variants by PCR and PCR-RFLPs, respectively, followed by PAGE and silver staining. RESULTS: For TSER, the most frequent allele was 2 R (52.56%), as well as the genotype 2 R/3R (42.3%). Comparison with Latin American, European, and American (USA) populations suggest a heterogeneous worldwide distribution (FST-value = 0.01564; p-value = 0.0000). When the G>C variant was included (2RG, 3RG, and 3RC), a high frequency of low expression genotypes was observed: 2RG/2RG, 2RG/3RC, and 3RC/3RC (84.6%). CONCLUSION: The high frequency of genotypes associated with low TS enzyme expression justifies obtaining the TYMS gene variant profile in Mexican patient's candidates to pharmaceutical treatments like 5'-Fluoracil, methotrexate, and pemetrex.

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.

Age-based life history of three groupers in the southern Gulf of Mexico.

The three most important grouper fishery species in southern Gulf of Mexico, Epinephelus morio, Mycteroperca bonaci and Mycteroperca microlepis, do not have life history parameters data reported such as growth, age and natural mortality essential to management. Individuals from the three species were captured in the Campeche Bank (CB) at different times from 1988 to 2001. Sagittae were thin-sectioned to count annuli: n = 1081 for E. morio, n = 920 for M. bonaci and n = 251 for M. microlepis. Otoliths from the three species exhibited successive opaque and translucent bands deposited with an annual frequency, occurring between January and April for E. morio and M. bonaci, and between January and March for M. microlepis. Estimated age in the three grouper species ranged from 0+ to 20 years. The most frequent ages were 7-10 years for E. morio and 8-12 years for M. bonaci and M. microlepis. The von Bertallanfy Growth Function model parameters (L∞ , K and t0 ) were consistent with reported growth patterns for Epinephelidae family species, as established by growth performance Ф' (near 3). The CB groupers appear to reach maximum ages over 13 years with K values between 0.09 and 0.12 year-1 , indicating all three studied species displayed relatively slow growth rate and medium longevity. Lifespan values ranged from 13 to 33 years for E. morio, from 18 to 30 years for M. bonaci and from 17 to 33 years for M. microlepis. A50 was 6.1 years for E. morio and 5.5 years for both M. bonaci and M. microlepis. Age at which all females were mature was 8 years for M. bonaci and 10 years for E. morio and M. microlepis. P50 was 9.3 years for E. morio, 13.6 years for M. bonaci and 11.6 years for M. microlepis. Age at which 100% of individuals were male was 13 years for E. morio, 19 years for M. bonaci and 15 years for M. microlepis. Values of M at age exhibited an exponential decrease with age for all three species, but overall values were 0.13 year-1 for E. morio, 0.14 year-1 for M. bonaci and 0.17 year-1 for M. microlepis. For the three species size at age varied by geographical distribution area, but particularly for E. morio the discrepancy in average size between published studies may be the consequence of the fishing effort exerted on the stock and/or the lack of regulation for the fishery prior to 2001; after this stock biomass fell below the reference limit point and was declared overexploited. Resource managers could use the information provided in this study as a reference, representing pre-overexploitation values, to evaluate the current status of these populations and ensure sustainable management actions for the CB grouper fisheries.

Methylation Status of Exon IV of the Brain-Derived Neurotrophic Factor (BDNF)-Encoding Gene in Patients with Non-Diabetic Hyperglycaemia (NDH) before and after a Lifestyle Intervention.

BDNF signalling in hypothalamic neuronal circuits is thought to regulate mammalian food intake. In light of this, we investigated how a lifestyle intervention influenced serum levels and DNA methylation of BDNF gene in fat tissue and buffy coat of NDH individuals. In total, 20 participants underwent anthropometric measurements/fasting blood tests and adipose tissue biopsy pre-/post-lifestyle (6 months) intervention. DNA was extracted from adipose tissue and buffy coat, bisulphite converted, and pyrosequencing was used to determine methylation levels in exon IV of the BDNF gene. RNA was extracted from buffy coat for gene expression analysis and serum BDNF levels were measured by ELISA. No differences were found in BDNF serum levels, but buffy coat mean BDNF gene methylation decreased post-intervention. There were correlations between BDNF serum levels and/or methylation and cardiometabolic markers. (i) Pre-intervention: for BDNF methylation, we found positive correlations between mean methylation in fat tissue and waist-hip ratio, and negative correlations between mean methylation in buffy coat and weight. (ii) Post-intervention: we found correlations between BDNF mean methylation in buffy coat and HbA1c, BDNF methylation in buffy coat and circulating IGFBP-2, and BDNF serum and insulin. Higher BDNF % methylation levels are known to reduce BNDF expression. The fall in buffy coat mean BDNF methylation plus the association between lower BDNF methylation (so potentially higher BDNF) and higher HbA1c and serum IGFBP-2 (as a marker of insulin sensitivity) and between lower serum BDNF and higher circulating insulin are evidence for the degree of BDNF gene methylation being implicated in insulinisation and glucose homeostasis, particularly after lifestyle change in NDH individuals.

Prevalence of protective haplotypes of the SLCO1B1 gene for statin transport in Mexican populations.

Aim: To evaluate the genetic distribution of the rs4149056 and rs2306283 variants in the SLCO1B1 gene in Mexican Mestizo (admixed) and Native American groups. Materials & methods: We recruited 360 volunteers who were qPCR-genotyped with TaqMan probes. Results: Allele and genotype frequencies are reported. Among the expected rs4149056-rs2306283 haplotypes, T-A (42.35-58.47%) was the most prevalent which relates to the normal activity of the OATP1B1 transporter. This was followed by the T-G haplotype associated with further statin transport and cholesterol reduction (32.49-43.76%). Conclusion: Based on these SLCO1B1 gene variants, we confirmed that a minimum fraction of the Mexican study populations would be at risk from decreasing simvastatin transport and the development of statin-induced myopathy.

Lay abstract The clinical response to statins, mainly atorvastatin and simvastatin, can be modified by interindividual variability including variations in the SLCO1B1 gene. This gene, that encodes the statin transporter OATP1B1, helps to regulate the cholesterol levels in the blood and is responsible for the presence of adverse drug reactions related to the statin consumption, such as muscular sickness. This study analyzes the distribution of the SLCO1B1 gene variants rs4149056 and rs2306283 in geographically dispersed samples of the two main populations in Mexico: two Mestizo (admixed) populations and three Native American groups. We found that the genetic combinations of T­A and T­G for the two SLCO1B1 gene variants ­ associated with normal or efficient activity of the transporter OATP1B ­ were predominant in all of the study population. Therefore, the SLCO1B1 gene variability suggests that a majority of the Mexican population will respond favorably to simvastatin and have a low risk of developing associated muscular complications.

Population diversity of three variants of the SLC47A2 gene (MATE2-K transporter) in Mexican Mestizos and Native Americans.

BACKGROUND: MATE2-K is an efflux transporter protein of organic cation expressed mainly in the kidney and encoded by the SLC47A2 gene. Different variants of this gene have shown an impact on the pharmacokinetics of various drugs, including metformin, which represents one of the most widely used drugs in treating type 2 diabetes. The SLC47A2 gene variants have been scarcely studied in Mexican populations, especially in Native American groups. For this reason, we analyzed the distribution of the variants rs12943590, rs35263947, and rs9900497 within the SLC47A2 gene in 173 Native Americans (Tarahumara, Huichol, Maya, Puerépecha) and 182 Mestizos (admixed) individuals from Mexico. METHODS AND RESULTS: Genotypes were determined through TaqMan probes (qPCR). The Hardy-Weinberg agreement was confirmed for all three SLC47A2 gene variants in all the Mexican populations analyzed. When worldwide populations were included for comparison purposes, for alleles and genotypes a relative interpopulation homogeneity was observed for rs35263947 (T allele; range 23.3-51.1%) and rs9900497 (T allele; range 18.6-40.9%). Conversely, heterogeneity was evident for rs12943590 (A allele, range 22.1-59.1%), where the most differentiated population was the Huichol, with high frequencies of the risk genotype associated with decreased response to metformin treatment (A/A = 40.9%). CONCLUSIONS: Although the SLC47A2 gene variants allow predicting favorable response to the metformin treatment in Mexican populations, the probable high frequency of ineffectiveness should be discarded in Huichols.

Dapagliflozin: an effective adjunctive treatment in type 1 diabetes.

INTRODUCTION: Many people with type 1 diabetes (T1DM) continue to run high HbA1c levels with an associated elevated risk of cardiovascular events and increased mortality. We describe here how adjunctive prescription of an SGLT2 inhibitor has improved the glycaemic control of several people with T1DM, where the new technology has been intensively deployed. METHODS: We report outcomes of six adults with T1DM who have been given dapagliflozin in East Cheshire, UK. Initiation was with education/support from the diabetes specialist nurses. All had an HbA1c of 70 mmol/mol (8.6%) or more before this was initiated. All had been monitoring glycemia with a FreeStyle Libre monitor for at least 6 months prior to this. RESULTS: The age range was 30-68 years. The mean duration of T1DM was 23.3 ± 5.5 years. All were on a basal-bolus regime. Over a 6 month period, HbA1c fell from 78.5 mmol/mol (9.3%) to 55 mmol/mol (7.2%). The greatest reduction in HbA1c was 57 mmol/mol (7.4%). Analysis of the FreeStyle Libre blood glucose records showed that the proportion of blood glucose readings on target (4-10 mmol/L) increased from 33.1 to 65.2% with the addition of dapagliflozin(P = 0.007). The proportion of blood glucose readings above target (>10 mmol/L) decreased from 68.0 to 26.4%, 6 months after initiation of dapagliflozin (P = 0.005). There was no increase in symptomatic hypoglycemia. CONCLUSION: Dapagliflozin as adjunctive therapy to basal-bolus regime insulin in individuals with T1DM was well tolerated and improved glycemic control with no increase in hypoglycemia. We provide further evidence of the value of this intervention.

The first record of Tremoctopus violaceus sensu stricto Delle Chiaje,1830 in southwestern Gulf of Mexico gives a hint of the taxonomic status of Tremoctopus gracilis.

Knowledge on species taxonomic identity is essential to understand biological and biogeographical processes and for studies on biodiversity. Species the genus Tremoctopus have been confused in the past and are inconsistently identified. To clarify of the taxonomic diagnosis Tremoctopus violaceus Delle Chiaje, 1830, an evaluation of morphological and meristic characters, as well as morphometric indices and genetic analyses, was undertaken. The analyzed octopod was an opportunistically collected mature female of 640 mm in total length, with a mantle length of 135 mm and a total weight of 1.02 kg. Evidence of autotomy as a defensive mechanism for protecting the egg mass is presented. The 16S haplotype sequenced from this specimen represents the first one publicly available for this species from the Gulf of Mexico. The genetic divergence between this haplotype and those reported from the Pacific Ocean is representative of interspecific variation in other taxa, which suggests that "T. violaceus" in the Pacific Ocean (KY649286, MN435565, and AJ252767) should be addressed as T. gracilis instead. Genetic evidence to separate T. violaceus and T. gracilis is presented. The studied specimen from the Gulf of Mexico represents the westernmost known occurrence of T. violaceus and the first record from the southwestern Gulf of Mexico.

Genetically defined favourable adiposity is not associated with a clinically meaningful difference in clinical course in people with type 2 diabetes but does associate with a favourable metabolic profile.

AIMS: Change in weight, HbA1c , lipids, blood pressure and cardiometabolic events over time is variable in individuals with type 2 diabetes. We hypothesised that people with a genetic predisposition to a more favourable adiposity distribution could have a less severe clinical course/progression. METHODS: We involved people with type 2 diabetes from two UK-based cohorts: 11,914 individuals with GP follow-up data from the UK Biobank and 723 from Salford. We generated a 'favourable adiposity' genetic score and conducted cross-sectional and longitudinal studies to test its association with weight, BMI, lipids, blood pressure, medication use and risk of myocardial infarction and stroke using 15 follow-up time points with 1-year intervals. RESULTS: The 'favourable adiposity' genetic score was cross-sectionally associated with higher weight (effect size per 1 standard deviation higher genetic score: 0.91 kg [0.59,1.23]) and BMI (0.30 kg/m2 [0.19,0.40]), but higher high-density lipoprotein (0.02 mmol/L [0.01,0.02]) and lower triglycerides (-0.04 mmol/L [-0.07, -0.02]) in the UK Biobank at baseline, and this pattern of association was consistent across follow-up. There was a trend for participants with higher 'favourable adiposity' genetic score to have lower risk of myocardial infarction and/or stroke (odds ratio 0.79 [0.62, 1.00]) compared to those with lower score. A one standard deviation higher score was associated with lower odds of using lipid-lowering (0.91 [0.86, 0.97]) and anti-hypertensive medication (0.95 [0.91, 0.99]). CONCLUSIONS: In individuals with type 2 diabetes, having more 'favourable adiposity' alleles is associated with a marginally better lipid profile long-term and having lower odds of requiring lipid-lowering or anti-hypertensive medication in spite of relatively higher adiposity.

The FreeStyle Libre flash glucose monitoring system: how it has improved glycaemic control for people with type 1 diabetes in Eastern Cheshire, UK.

INTRODUCTION: Many people with type 1 diabetes continue to run high HbA1c levels with associated elevated risk of cardiovascular events and increased mortality. We describe here how use of the FreeStyle Libre flash monitor has improved the glycaemic control of many people with type 1 diabetes where the new technology has been intensively deployed. METHODS: We report the outcomes of 92 consecutive adults (18 years of age or more) with type 1 diabetes who have begun using the FreeStyle Libre flash glucose monitor in East Cheshire, UK. Initiation was with education and support from one of the diabetes specialist nurses. An HbA1c of 60 mmol/mol (7.6%) was taken as the threshold for suboptimal glycaemic control. RESULTS: The mean cohort age was 43 years for men and 39 years for women (overall range 17-83 years). In 92 consecutive users, HbA1c decreased by an average of 10.7 mmol/mol (0.98%) after 3 months, and by 16.1 mmol/mol (1.47%) after 6 months. There was also a narrowing of the distribution of HbA1c, with many fewer people running high HbA1c ≥80 mmol/mol (9.5%). After the 6-month follow-up, two 2/92 users did not wish to continue with the monitoring. CONCLUSION: Flash glucose monitoring has great potential for the management of type 1 diabetes in the adult population and improving metabolic control/quality of life for people across the world. The technology provides significantly more data than the intermittent results obtained by traditional subcutaneous blood glucose monitoring, which may not capture intervals of extreme variability or nocturnal events.

Association of the 5HTTLPR Polymorphism with Obesity in Mexican Women with High Native American Ancestry.

Aims: The 5HTT gene has been associated with obesity; this study aimed to determine the association between L- and S-alleles at the 5HTTLPR polymorphism with obesity in indigenous Mexican populations. Materials and Methods: A total of 362 individuals, 289 belonging to eight Native American (NA) groups; 40 Mexican mestizos; and 33 Caucasian Mennonites were enrolled in a cross-sectional study. High (≥90%) and low (<90%) NA ancestry was molecularly determined. A body mass index >30 kg/m2 was considered as obese. The L- and S-alleles of the 5HTTLPR locus were identified by PCR; the association between alleles and obesity was performed by logistic regression analysis. Results: A significantly lower prevalence of obesity (35%) was observed in participants from communities with high NA ancestry (p < 0.005). Under a dominant heritance model the L-allele was associated with obesity in women with high NA ancestry (odds ratio [OR] 7.27; 95% confidence interval [CI] 1.6-32.5; p = 0.009) but not in women with low NA ancestry (OR 0.83; 95% CI 0.3-2.2; p = 0.71); no association was observed in men. Conclusion: Our results suggest that the 5HTTLPR L-allele is a risk factor for developing obesity in Mexican women with high NA ancestry (≥90%).

Silk fibroin nanofibrous mats for visible sensing of oxidative stress in cutaneous wounds.

Wound healing is of major clinical concern and is constantly being explored for early restoration and enhanced recovery. While the etiology of the wound healing is multifactorial, high inflammation and increased oxidative stress which results in chronic inflammation, endothelial dysfunction and collagen degradation, delay the overall healing process. Thus, visual sensing of the oxidative stress would be highly informative in the successful implementation of wound healing therapies based on specific requirements. In this study, electrospinning was used to fabricate silk fibroin nanofibrous mats infused with Amplex red capable of detecting hydrogen peroxide, a reactive oxygen molecule. These mats produced a visible change in color with the limit of detection at 1 µM H2O2 concentration. In vivo studies carried out in diabetic mice with impaired wounds also displayed a visible change in color of the mats infused with Amplex red within 24 hours. These electrospun silk fibroin nanofibrous Amplex infused mats has the potential to enable a futuristic platform where decisions can be made for enhanced wound healing therapy.

General practice (GP) level analysis shows that patients' own perceptions of support within primary care as reported in the GP patient survey (GPPS) are as important as medication and services in improving glycaemic control.

BACKGROUND: The way that GP practices organize their services impacts as much on glycaemia in type 2 diabetes as does prescribing. AIM: Our aim was to evaluate the link between patients' own perception of support within primary care and the % patients at each GP practice at target glycaemic control (TGC) and at high glycaemic risk (HGR). DESIGN AND SETTING: Utilisation of National Diabetes Audit (NDA) available data combined with the General practitioner patient survey (GPPS). METHOD: The NDA 2016_17 published data on numbers of type 2 patients, levels of local diabetes services and the target glycaemic control (TGC) % and high glycaemic risk (HGR) % achieved. The GPPS 2017 published % "No" responses from long term condition (LTC) patients to the question "In the last 6 months, had you enough support from local services or organisations to help manage LTCs?". Multivariate regression was used on the set of indicators capturing patients' demographics and services provided. RESULTS: 6498 practices were included (with more than 2.5 million T2DM patients) and median values with band limits that included 95% practices for % "No" response to the question above was 12% (2%-30%), for TGC 67% (54%-78%) and for HGR 6% (2%-13%). The model accounted for 25% TGC variance and 26% HGR variance. The standardised ß values shown as (TGC/HGR) (+=more people; -=less people) for older age (+0.24/-0.25), sulphonylurea use (-0.21/+0.14), greater social disadvantage (-0.09/+0.21), GPPS Support %No (-0.08/+0.12), %Completion 8 checks (+0.09/-0.12) and metformin use (+0.11/-0.05). CONCLUSION: The relation between the person with diabetes and clinician in primary care is shown to be quantitatively potentially as important in influencing glycaemic outcome as the services provided and medication prescribed. We suggest that all of us in who work in the health care system can bear this in mind in our everyday work.

A possible new spawning area for Atlantic bluefin tuna (Thunnus thynnus): the first histologic evidence of reproductive activity in the southern Gulf of Mexico.

The number of studies of reproductive biology for Atlantic bluefin tuna carried out in the Gulf of Mexico is significantly lower than those undertaken in the Mediterranean Sea. Four spawning areas have been found for the eastern Atlantic bluefin tuna stock in the Mediterranean Sea, so it is not implausible that there is more than one spawning area in the Gulf of Mexico for the western Atlantic bluefin tuna stock. The individuals used in this study were caught as bycatch by the Mexican surface longline fleet between January and April 2015. A total of 63 individuals ranging between 192 and 293 cm LF (mean = 238 ± 22.52 cm) were measured. Gonads from 46 fish (31 females and 15 males) were collected for histological examination. All the individuals were classified as mature; 25 were reproductively active (in spawning capable and spawning stages). The histological analysis indicates spawning activity in Mexican waters (the southern Gulf of Mexico). Spawning occurred in March and April, when the sea surface temperature was 25.57 °C ± 0.69 in March and 27.03 °C ± 0.69 in April. Information on the location of the spawning areas is necessary for a correct management of species. The present study provides the first histological evidence of reproductive activity in Mexican waters, and indicates a wider spawning area, beyond just the northern zone, potentially encompassing the entire Gulf of Mexico.

Inference of maternal uniparental disomy of the entire chromosome 2 from a paternity test.

Atypical situations arise during the constant resolution of paternity cases, which constitute challenges requiring additional genetic systems and non-standard methods. We report a paternity case presenting three alleged father (AF)-child incompatibilities for the markers TPOX, D2S441, and the indel locus B02 (11/11 vs 8/8; 14/14 vs 10/10; 2/2 vs1/1, respectively). Considering the presence of mutations/null alleles, the residual paternity indexes (PI) obtained with 23 autosomal short tandem repeats (STRs) and 38 indels suggest that the AF is the father (PI = 1.94e+011). Although the presence of few incompatibilities also could imply paternity of the AF brother, this hypothesis was less probable (PI = 3.20e+9) (W = 98.4 vs 1.6%, respectively). The inclusion of 23 Y-STR loci confirmed the paternity relationship in this case (global PI = 6.08e+15). However, the two multistep STRs and one indel incompatibilities allow discarding the mutation possibility. On the other hand, the confirmation of the homozygous STR genotypes with two different human identification kits and the low probability to find three null alleles (3.10e-8) allow rejecting the null allele presence hypothesis. Conversely, the child's homozygous genotype for maternal alleles in four markers located in the p and q arms of the chromosome 2 (TPOX, D2S441, D2S1338, and B02) suggests that maternal uniparental isodisomy better explains the relationship despite the presence of three paternal incompatibilities. In brief, when multiple incompatibilities are observed in paternity testing, the chromosomal location of the excluding loci and the use of additional genetic systems can be crucial to get confident kinship conclusions.

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.

Genetic variability among Mexican Mestizo and Amerindian populations based on three ABCB1 polymorphisms.

The most widely studied polymorphisms of the ABCB1 gene are rs1128503 (c.1236C>T), rs2032582 (c.2677G>T/A), and rs1045642 (c.3435C>T). Although variation in ABCB1 allele frequencies among Mexican Mestizos (admixed) from different regions has been observed, Mexican Amerindians have been poorly studied. We aimed to describe the genetic variability of these three ABCB1 polymorphisms in a total sample of 273 Mexican volunteers that included Mestizos from the state of Yucatán, and Amerindians from seven populations (Tarahumara, Mayo, Huichol, Purépecha, Nahua, Tojolabal, and Maya). Genotypes were determined by means of Taq Man probes (qPCR). Genotype distribution was in Hardy-Weinberg equilibrium for all three ABCB1polymorphisms in the eight Mexican populations analyzed. For c.1236C>T and c.3435C>T, the heterozygous C/T was the most frequent genotype in the majority of the studied Mexican populations (range 30.8-65.4%), while heterozygous G/T was the most common genotype for c.2677G>T/A (range 25.9-51.2%), mainly followed by G/G (range 3.2-47.1%) and T/T (range 7.0-35.5%). 12 haplotypes were estimated from the three ABCB1 polymorphisms analyzed, with TTT the most frequent haplotype (mean, 37.0%). Genetic differentiation was demonstrated among the studied Mexican populations (Fst p value < 0.0001), which could imply a diverse drug response or a risk for adverse drug reactions to ABCB1 substrates. Although differences among Amerindians are probably due to genetic drift effects, for Mestizos this could imply variation in admixture composition. In conclusion, interpopulation variability in the observed frequencies of ABCB1 polymorphisms among Mexican Mestizos and Amerindians allow predicting diverse drug responses to ABCB1 substrates in these populations.