Natural hybridization between wheat (Triticum aestivum L.) and its wild relatives Aegilops geniculata Roth and Aegilops triuncialis L.

BACKGROUND: Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop-wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses. RESULTS: The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis. CONCLUSION: The detection of Aegilops spp.-wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry.

Dynamics of canopy-dwelling arthropods under different weed management options, including glyphosate, in conventional and genetically modified insect-resistant maize.

The use of genetically modified varieties tolerant to herbicides (HT varieties) and resistant to insects (Bt varieties) in combination with application of a broad-spectrum herbicide such as glyphosate could be an effective option for the simultaneous control of weeds and pests in maize. Nevertheless, the possible impact of these tools on nontarget arthropods still needs to be evaluated. In a field study in central Spain, potential changes in populations of canopy-dwelling arthropods in Bt maize under different weed management options, including glyphosate application, were investigated. Canopy-dwelling arthropods were sampled by visual inspection and yellow sticky traps. The Bt variety had no effect on any group of studied arthropods, except for the expected case of corn borers-the target pests of Bt maize. Regarding the effects of herbicide regimes, the only observed difference was a lower abundance of Cicadellidae and Mymaridae on yellow sticky traps in plots not treated with pre-emergence herbicides. This effect was especially pronounced in a treatment involving two glyphosate applications. The decrease in Cicadellidae and Mymaridae populations was associated with a higher density of weeds in plots, which may have hindered colonization of the crop by leafhoppers. These differences, however, were only significant in the last year of the study. The low likelihood of the use of glyphosate- and herbicide-tolerant varieties for weed control triggering important effects on the nontarget arthropod fauna of the maize canopy is discussed.

Association between favourable changes in objectively measured physical activity and telomere length after a lifestyle intervention in pediatric patients with abdominal obesity.

The purpose of this study was to assess the effect of physical activity (PA) changes, measured by accelerometry, on telomere length (TL) in pediatric patients with abdominal obesity after a lifestyle intervention. One hundred and twenty-one children (7-16 years old) with abdominal obesity were randomized to the intervention (a moderately hypocaloric Mediterranean diet) or the usual care group (standard pediatric recommendations) for 22 months (a 2 month intensive phase and a subsequent 20 month follow-up). Both groups were encouraged to accumulate an extra 200 min/week of PA. TL was measured by MMqPCR. Data were analyzed in 102 subjects after 2 months and 64 subjects at the first 10 months of follow-up. Light PA level decreased in both groups after 12 months of intervention. At month 2, moderate to vigorous PA (MVPA) increased in the intervention group (+5.4 min/day, p = 0.035) and so did sedentary time in the usual care group (+49.7 min/day, p = 0.010). TL changes were positively associated (p < 0.050) with metabolic equivalents (METs), MVPA level, and number of steps, and were inversely associated with sedentary and light PA levels in the intervention group after the intensive phase. In conclusion, favourable changes in PA levels in the intensive phase of a lifestyle intervention could contribute to TL maintenance in a pediatric population with abdominal obesity. Novelty Changes in physical activity levels had a direct effect on telomere length, a biomarker of cellular aging and oxidative stress. PA advice based on The American College of Sports Medicine included in this intervention is easy to implement in primary care.

Changes in objectively measured physical activity after a multidisciplinary lifestyle intervention in children with abdominal obesity: a randomized control trial.

BACKGROUND: Physical activity (PA) is associated with changes in body composition that affect insulin sensitivity and leptin levels. Few studies have assessed the effect of lifestyle interventions on changes in objectively measured PA levels in obese children. To evaluate the effects of a multidisciplinary lifestyle intervention on anthropometric indices, biochemical parameters and accelerometer measured PA in abdominal obese children. METHODS: A randomized control trial was performed in 106 children and adolescents with abdominal obesity. Participants were randomly assigned to usual or intensive care group for 8-week. PA was measured by accelerometry over four days including, at least, two weekdays in all participants. Both groups were encouraged to accumulate an extra time of 200 min per week in their PA. RESULTS: At baseline, 75% of subjects do not fulfill the WHO recommendation of being more than 60 min/day on moderate-to-vigorous PA (MVPA). The intensive care group achieved a significant reduction in anthropometric indexes compared to the usual care but no significant change was found in biochemical or PA parameters. Both groups achieved a significant reduction in light PA. Interestingly, intensive care participants significantly increased MVPA in 5.5 min/day. Moreover, an inverse association between changes in MVPA and leptin levels was found. CONCLUSION: The two lifestyle intervention reduced anthropometric indexes and lowered light PA in abdominal obese children. No significant differences were observed between intensive care and usual care in regard to PA. Intensive care participants significantly increase physical activity (MVPA) and, changes in MVPA were inversely associated with changes in leptin levels after the intervention. TRIAL REGISTRATION: ClinicalTrials.gov , Identifier: NCT03147261 . Registered 10 May 2017. Retrospectively registered.

Improved Diet Quality and Nutrient Adequacy in Children and Adolescents with Abdominal Obesity after a Lifestyle Intervention.

High rates of childhood obesity require integral treatment with lifestyle modifications that achieve weight loss. We evaluated a lifestyle intervention on nutrient adequacy and diet quality in children and adolescents with abdominal obesity. A randomized controlled trial was performed on 107 participants, assigned either to a usual care group or to an intensive care group that followed a moderate hypocaloric Mediterranean diet and received nutritional education. Intake adequacy was evaluated using Dietary Reference Intakes and diet quality through the Diet Quality Index for Adolescents (DQI-A), the Healthy Lifestyle Diet-Index (HLD-I) and the Mediterranean Diet Quality Index (KIDMED). Both groups achieved a significant reduction in BMI standard deviation score (BMI-SDS), glucose and total cholesterol levels. Intake of Calcium, Iodine and vitamin D were higher in the intensive care group, with enhanced compliance with recommendations. Higher dietary scores were associated with lower micronutrient inadequacy. DQI-A and HLD-I were significantly higher in the intensive care group vs. usual care group after the treatment. In conclusion, we observed that an intensive lifestyle intervention was able to reduce BMI-SDS in children with abdominal obesity. Furthermore, participants significantly improved dietary indices getting closer to the nutritional recommendations. Therefore, these diet quality indices could be a valid indicator to evaluate micronutrient adequacy.

Cyclical variation in the incidence of childhood-onset type 1 diabetes during 40 years in Navarra (Spain).

OBJECTIVE: To trace the evolution of type 1 diabetes (T1D) in Navarre in children under 15, between 1977 and 2016, and their characteristics at onset regarding age and sex. SUBJECTS AND METHODS: We performed a descriptive analysis, using prospective-retrospective information. The study included all cases of T1D diagnosed in Navarre in children aged 0 to 14 years old from 1 January 1977 until 31 December 2016. The capture-recapture method was used, retrieving information from three independent sources: the five hospitals in Navarre as a primary source, and the Navarre Association of Diabetics (ANADI) and the primary healthcare system as the secondary source. Estimates and confidence intervals were calculated assuming a subjacent Poisson distribution. Chi square test was used to compare incidence between groups. The analysis of changes in incidence since 1977, adjusted for age group, sex and year of diagnosis, were evaluated with a multivariate Poisson regression model and joinpoint regression. RESULTS: A total of 577 cases were registered resulting in a crude incidence rate of 14.99/100 000 inhabitants-year (95% confidence interval [CI]: 13.79-16.26). From 1977, the incidence has increased in cycles, reaching an incidence rate of 22.98 (95% CI: 18.52-28.21) in 2016. The relative annual increase is 3% (95% CI: 2.3-3.8). The highest incidence is in the 10 to 14 age group (P < 0.001). No differences in sex were found. The mean age at onset in children under 15 years has not changed significantly (P = 0.572). CONCLUSIONS: The incidence of T1D in Navarre has increased 4-fold in the last four decades but is stable since 2001.

Frequent and Rare HABP2 Variants Are Not Associated with Increased Susceptibility to Familial Nonmedullary Thyroid Carcinoma in the Spanish Population.

BACKGROUND/AIMS: A genomic HABP2 variant was proposed to be responsible for familial nonmedullary thyroid carcinoma (FNMTC). However, its involvement has been questioned in subsequent studies. We aimed to identify genetic HABP2 mutations in a series of FNMTC patients and investigate their involvement in the disease. METHODS: HABP2 was sequenced from 6 index patients. Presence of the variants was investigated in all members of one family. Somatic BRAF and RAS "hotspot" mutations were investigated by the IdyllaTM BRAF Mutation Test and/or Sanger sequencing. RESULTS: Two HABP2 variants (p.E393Q and p.G534E) were identified in the index patient from one family with papillary thyroid carcinoma (PTC) (follicular variant). The prevalence of p.E393Q in Spanish control alleles was 0.5% and that of p.G534E was 5.1%. However, neither change cosegregated with the phenotype in 3 affected members and 5 healthy members of the kindred. Interestingly, all 3 members affected by PTC harbored the p.V600E somatic mutation in BRAF. CONCLUSIONS: The variant G534E is prevalent in the Spanish population (5.1%); however, p.E393Q is rare (< 1%) and none cosegregated with the FNMTC phenotype. The presence of the noninheritable V600E BRAF mutation in this family supports Knudson's "double-hit" hypothesis for cancer development and suggests the involvement of more than 1 gene in the clinical expression of FNMTC.

La incidencia de diabetes tipo 1, en Navarra, se ha estabilizado en los últimos 8 años / Incidence of type 1 diabetes mellitus in Navarre stabilized in the last eight years

Objetivo: La incidencia de diabetes tipo 1 plantea diversas controversias. Nuestro objetivo consiste en contribuir a responder a las siguientes preguntas: ¿Está aumentando la incidencia? ¿Se adelanta la edad al comienzo? ¿Cuáles son las diferencias entre sexos? y ¿Cuáles son las características en adultos? Métodos: Estudio transversal descriptivo, con los datos obtenidos de una fuente primaria y 3 secundarias, entre el 01/01/2009 y el 31/12/2016, en Navarra. Se estimaron las tasas anuales y la tasa de incidencia, expresada por 100.000 personas-año de riesgo, en el período estudiado, por grupos de edad y sexo. La comparación de la incidencia por sexo y edad se ha realizado estimando la razón de incidencia a partir de métodos de regresión de Poisson. La exhaustividad del Registro fue del 96,08%. Resultados: Durante estos 8 años, se registraron 428 nuevos casos (incidencia: 8,4/100.000 habitantes-año; IC95%: 7,6-9,2). La incidencia ha permanecido estable y en menores de 15 años (21,5) es mayor que en adultos (5,9). El grupo de edad con mayor incidencia es el de 10 a 14 años en varones y el de 5 a 9 años en mujeres. A partir de aquí, disminuye con la edad. Predomina en hombres entre los 10 y 45 años y, separando por cuatrienios, no hay cambios en la edad al comienzo. Conclusiones: Navarra muestra muy alta incidencia de diabetes tipo 1 en la infancia y baja incidencia en adultos. El pico de incidencia se da antes en las niñas, pero la enfermedad predomina en varones. Ni la incidencia ni la edad al comienzo se han modificado

Objectives: Incidence of type 1 diabetes mellitus raises a number of controversies. Our study aim was to contribute to answer the following questions: Is incidence of T1DM increasing? Is age at onset of type 1 diabetes mellitus decreasing? Which are the sex differences? Which are the characteristics in adults? Methods: A cross-sectional descriptive study using data from a primary source and 3 secondary sources from Navarre collected between 01/01/2009 and 12/31/2016. Annual incidence rates and incidence rate expressed as 100,000 person-years were estimated in the study period by age and sex group. The comparison of the sex and age incidence was made estimating the incidence rate using Poisson's regression methods. The completeness of the register was 96.08%. Results: During the 8 years analyzed, 428 new cases of type 1 diabetes mellitus were reported (incidence: 8.4/100,000 person-years, 95% CI: 7.6-9.2). Incidence has remained stable and is higher in the group under 15 years old (21.5) than in adults (5.9). Males aged 10-14 years and females aged 5-9 years were the groups with the highest incidence. Incidence then decreased with increasing age. Type 1 diabetes mellitus predominates in males aged 10-45 years, and no changes were seen in age at onset when analized by four-year periods. Conclusion: Navarre shows a very high incidence of type 1 diabetes mellitus in childhood and a low incidence in adulthood. Peak incidence is seen earlier in girls, but the disease predominates in males. Neither incidence nor age at onset have changed

Incidence of type 1 diabetes mellitus in Navarre stabilized in the last eight years. / La incidencia de diabetes tipo 1, en Navarra, se ha estabilizado en los últimos 8 años.

OBJECTIVES: Incidence of type 1 diabetes mellitus raises a number of controversies. Our study aim was to contribute to answer the following questions: Is incidence of T1DM increasing? Is age at onset of type 1 diabetes mellitus decreasing? Which are the sex differences? Which are the characteristics in adults? METHODS: A cross-sectional descriptive study using data from a primary source and 3 secondary sources from Navarre collected between 01/01/2009 and 12/31/2016. Annual incidence rates and incidence rate expressed as 100,000 person-years were estimated in the study period by age and sex group. The comparison of the sex and age incidence was made estimating the incidence rate using Poisson's regression methods. The completeness of the register was 96.08%. RESULTS: During the 8 years analyzed, 428 new cases of type 1 diabetes mellitus were reported (incidence: 8.4/100,000 person-years, 95% CI: 7.6-9.2). Incidence has remained stable and is higher in the group under 15 years old (21.5) than in adults (5.9). Males aged 10-14 years and females aged 5-9 years were the groups with the highest incidence. Incidence then decreased with increasing age. Type 1 diabetes mellitus predominates in males aged 10-45 years, and no changes were seen in age at onset when analized by four-year periods. CONCLUSION: Navarre shows a very high incidence of type 1 diabetes mellitus in childhood and a low incidence in adulthood. Peak incidence is seen earlier in girls, but the disease predominates in males. Neither incidence nor age at onset have changed.

Weeds and ground-dwelling predators' response to two different weed management systems in glyphosate-tolerant cotton: A farm-scale study.

The use of glyphosate, as a post-emergence broad-spectrum herbicide in genetically modified glyphosate-tolerant (GT) cotton, supposes a big change in weed management programs with respect to a conventional regime. Thus, alterations in arable flora and arthropod fauna must be considered when evaluating their potential impacts. A 3-year farm-scale study was conducted in a 2-ha GT cotton crop, in southern Spain, to compare the effects of conventional and glyphosate herbicide regimes on weed abundance and diversity and their consequences for ground-dwelling predators. Surveys reveal that weed density was relatively low within all treatments with a few dominant species, with significantly higher weed densities and modifications of the floristic composition in glyphosate-treated plots that led to an increase in the abundance of Portulaca oleracea and to a reduction in plant diversity. The activity-density of the main predatory arthropod taxa (spiders, ground beetles, rove beetles and earwigs) varied among years, but no significant differences were obtained between conventional and glyphosate herbicide regimes. However, significant differences between treatments were obtained for ground beetles species richness and diversity, being higher under the glyphosate herbicide regime, and a positive correlation with weed density could be established for both parameters. The implications of these findings to weed control in GT cotton are discussed.

Serum oxidized low-density lipoprotein levels are related to cardiometabolic risk and decreased after a weight loss treatment in obese children and adolescents.

BACKGROUND AND AIMS: The oxidation of low-density lipoprotein (LDL) cholesterol particles is an early atherogeninic event. Obese pediatric populations have higher levels of oxidized LDL (oxLDL) than normal weight children. The aim of this study was to evaluate the effect of a weight loss program on the biochemical profile and oxLDL levels in Spanish obese children and adolescents. METHODS: Forty obese children (mean age 11 years, 51% boys) followed a 10-week weight loss program. They were dichotomized at the median of body mass index-standard deviation score (BMI-SDS) change, as high (HR) and low responders (LR) after the intervention. The intervention included a moderate energy-restricted diet, nutritional education, and family involvement. Anthropometric and biochemical measurements were performed at the beginning and during the follow up. A cardiometabolic risk score (CMS) was calculated considering metabolic risk factors. RESULTS: Higher baseline oxLDL levels were associated with a higher CMS in obese children (P < .001). After the intervention, oxLDL significantly decreased in the HR group. Moreover, a positive correlation between changes in oxLDL and BMI-SDS (r = 0.385, P = .015) was found after the weight loss program. Interestingly, multiple-adjusted regression models showed an association between changes in total cholesterol [B: 0.127, 95% confidence interval (CI): 0.06 to 0.20] and LDL-cholesterol (B: 0.173, 95% CI: 0.08 to 0.26) with changes in oxLDL. CONCLUSIONS: Higher baseline oxLDL levels were associated with a higher CMS in obese children. After the weight loss program, a decrease in oxLDL levels was found in HR subjects and the oxLDL levels were associated with BMI-SDS and cholesterol levels.

Pollen-Mediated Movement of Herbicide Resistance Genes in Lolium rigidum.

The transfer of herbicide resistance genes by pollen is a major concern in cross-pollinated species such as annual ryegrass (Lolium rigidum). A two-year study was conducted in the greenhouse, under favorable conditions for pollination, to generate information on potential maximum cross-pollination. This maximum cross-pollination rate was 56.1%. A three-year field trial was also conducted to study the cross-pollination rates in terms of distance and orientation to an herbicide-resistant pollen source. Under field conditions, cross-pollination rates varied from 5.5% to 11.6% in plants adjacent to the pollen source and decreased with increasing distances (1.5 to 8.9% at 15 m distance and up to 4.1% at 25 m in the downwind direction). Environmental conditions influenced the cross-pollination both under greenhouse and field conditions. Data were fit to an exponential decay model to predict gene flow at increasing distances. This model predicted an average gene flow of 7.1% when the pollen donor and recipient plants were at 0 m distance from each other. Pollen-mediated gene flow declined by 50% at 16.7 m from the pollen source, yet under downwind conditions gene flow of 5.2% was predicted at 25 m, the farthest distance studied. Knowledge of cross-pollination rates will be useful for assessing the spread of herbicide resistance genes in L. rigidum and in developing appropriate strategies for its mitigation.

Peripheral blood mononuclear cell gene expression profile in obese boys who followed a moderate energy-restricted diet: differences between high and low responders at baseline and after the intervention.

The present study analyses the gene expression profile of peripheral blood mononuclear cells (PBMC) from obese boys. The aims of the present study were to identify baseline differences between low responders (LR) and high responders (HR) after 10 weeks of a moderate energy-restricted dietary intervention, and to compare the gene expression profile between the baseline and the endpoint of the nutritional intervention. Spanish obese boys (age 10-14 years) were advised to follow a 10-week moderate energy-restricted diet. Participants were classified into two groups based on the association between the response to the nutritional intervention and the changes in BMI standard deviation score (BMI-SDS): HR group (n 6), who had a more decreased BMI-SDS; LR group (n 6), who either maintained or had an even increased BMI-SDS. The expression of 28,869 genes was analysed in PBMC from both groups at baseline and after the nutritional intervention, using the Affymetrix Human Gene 1.1 ST 24-Array plate microarray. At baseline, the HR group showed a lower expression of inflammation and immune response-related pathways, which suggests that the LR group could have a more developed pro-inflammatory phenotype. Concomitantly, LEPR and SIRPB1 genes were highly expressed in the LR group, indicating a tendency towards an impaired immune response and leptin resistance. Moreover, the moderate energy-restricted diet was able to down-regulate the inflammatory 'mitogen-activated protein kinase signalling pathway' in the HR group, as well as some inflammatory genes (AREG and TNFAIP3). The present study confirms that changes in the gene expression profile of PBMC in obese boys may help to understand the weight-loss response. However, further research is required to confirm these findings.

Decreased cardiotrophin-1 levels are associated with a lower risk of developing the metabolic syndrome in overweight/obese children after a weight loss program.

OBJECTIVE: Cardiotrophin-1 (CT-1) shares some similarities with other cytokines, and participates in the control of energy metabolism. Higher circulating levels are observed in obese humans, but little information is gathered in weight loss (WL) programs. Therefore, we aimed to investigate the association of serum CT-1 levels with metabolic variables and the risk of developing metabolic syndrome (MetS) after a WL program in overweight/obese children. SUBJECTS AND METHODS: Forty-four overweight/obese children (mean age 11.5 y; 50% males) undergoing a 10-week WL program were enrolled. Subjects were dichotomized at the median of Body Mass Index-Standard Deviation Score (BMI-SDS) change, as high and low responders after intervention. RESULTS: CT-1 levels were significantly reduced (-48 fmol/mL, p=0.043) in the high responder group after the WL program. They had significantly lower body weight (-3.7 kg, p<0.001), body fat mass (-8%, p<0.001), BMI-SDS (-0.78, p<0.001) and waist circumference (-5.4 cm, p<0.001), and a significant improvement in lipid and glucose profiles (p<0.05). Interestingly, decreased CT-1 levels significantly predicted changes in total cholesterol (41%) and LDL-cholesterol (28%). Moreover, in our participants the lower the CT-1 levels, the higher the reduction in MetS risk components, after the 10-week intervention, (p-ANCOVA=0.040, p-trend=0.024). CONCLUSION: We showed, for the first time, a reduction in serum CT-1 levels after a WL program and this decrease in CT-1 was strongly associated with a reduction in cholesterol levels and in MetS risk factors in overweight/obese children. Our findings may suggest that CT-1 could be an indirect marker for the diagnosis of MetS in this population.

[Differences by age and gender in the incidence of type 1 diabetes in Navarre, Spain (2009-2011)]. / Diferencias por edad y sexo en la incidencia de diabetes tipo 1 en Navarra (2009-2011).

OBJECTIVE: To determine the incidence of type 1 diabetes in Navarre, irrespective of age, from 2009 to 2011, and its characteristics at onset by age and gender. METHOD: A descriptive cross-sectional study was conducted. Data were obtained from one primary and three secondary sources. Poisson regression models were used to analyze differences in incidence rates among age groups and between male and female patients. RESULTS: We detected 167 new cases (incidence: 8.7/100,000 inhabitants-year; 95%CI: 7.4-10.1). The incidence was higher in children than in adults and was highest in the group aged 10-14 years. The incidence was higher in males than in females. The incidence increased with age in boys under 15 years but not in girls. CONCLUSIONS: The incidence of type 1 diabetes in children and young adults in Navarre is among the highest in Europe. Differences were found by age and gender.

Pollen-mediated gene flow in wheat (Triticum aestivum L.) in a semiarid field environment in Spain.

Transgenic wheat (Triticum aestivum L.) varieties are being developed and field-tested in various countries. Concerns regarding gene flow from genetically modified (GM) crops to non-GM crops have stimulated research to estimate outcrossing in wheat prior to the release and commercialization of any transgenic cultivars. The aim is to ensure that coexistence of all types of wheat with GM wheat is feasible in accordance with current regulations. The present study describes the result of a field experiment under the semi-arid climate conditions of Madrid, Spain, at two locations ("La Canaleja" and "El Encin" experimental stations) in Madrid over a 3-year period, from 2005 to 2007. The experimental design consisted of a 50 × 50 m wheat pollen source sown with wheat cultivars resistant to the herbicide chlortoluron ('Deganit' and 'Castan' respectively) and three susceptible receptor cultivars ('Abental', 'Altria' and 'Recital') sown in replicated 1 × 1 m plots at different distances (0, 1, 3, 5, 10, 20, 40, 80 and 100 m) and four directions. Outcrossing rates were measured as a percentage of herbicide-resistant hybrids using an herbicide-screening assay. Outcrossing was greatest near the pollen source, averaging 0.029% at 0 m distance at "La Canaleja" and 0.337% at "El Encin", both below the 0.9% European Union regulated threshold, although a maximum outcrossing rate of 3.5% was detected in one recipient plot. These percentages declined rapidly as the distance increased, but hybrids were detected at different rates at distances of up to 100 m, the maximum distance of the experiment. Environmental conditions, as drought in 2004-2005 and 2005-2006, may have influenced the extent of outcrossing. These assays carried out in wheat under semi-arid conditions in Europe provide a more complete assessment of pollen-mediated gene flow in this crop.

Evidence of natural hybridization between Aegilops geniculata and wheat under field conditions in Central Spain.

This study deals with hybrids between Aegilops geniculata and bread wheat, Triticum aestivum L., detected in two Ae. geniculata populations in the "Meseta Central", Spain's central plateau where wheat is a major crop. Morphological traits and pentaploid chromosome numbers were used to identify hybrids in 2004 and 2005. The frequency of hybridization under natural conditions was calculated for one of these populations. Six hybrids were detected from a sample of 3158 seeds from this population. The hybrids were mainly sterile but seed set can be found. This study extends the range of documented hybridization to include central Spain. The potential risks associated with natural hybridization in the context of transgenic wheat cultivation are discussed.

[Association of vitamin D receptor gene polymorphism with type 1 diabetes mellitus in two Spanish populations]. / Asociación de los polimorfismos del gen del receptor de la vitamina D con la diabetes mellitus tipo 1 en dos poblaciones españolas.

BACKGROUND AND OBJECTIVE: In order to assess whether vitamin D receptor gene polymorphisms are involved in the genetic regulation of type 1 diabetes susceptibility, a case-control study was conducted in two Spanish populations with different genetic backgrounds. PATIENTS AND METHOD: 155 patients with childhood-onset type 1 diabetes and 280 healthy controls from Barcelona, and 89 patients and 116 controls from Navarre were studied for vitamin D receptor gene polymorphisms in peripheral blood DNA. Intron 8 (BsmI) and exon 2 (FokI) segments were amplified by PCR and sequenced to determine each corresponding genotype. Differences for allele, genotype and combined haplotype and genotype distribution between patients and controls within each population and between the two populations were analyzed. RESULTS: BsmI genotype and allele frequencies showed a tendency towards increased bb genotype and b allele frequencies in Barcelona patients and the tendency was inverse in Navarre. FokI polymorphism distribution analysis showed a significant decrease in ff genotype (p = 0.016) in patients versus controls from Navarre. Combined genotypes showed homozygous bb/FF genotype to be increased in Barcelona patients (p = 0.04) whereas homozygous bb/ff genotype was decreased in Navarre patients (p = 0.02) versus their corresponding controls. BF haplotype frequency distribution between patients and controls was inverse and significantly different between Barcelona and Navarre (p = 0.04). CONCLUSIONS: Combined genotypes for vitamin D receptor gene polymorphisms at intron 8 and exon 2 suggest that the more active form of vitamin D receptor gene (FF genotype) can be increased in Mediterranean diabetic patients whereas the less active form (ff genotype) can be decreased in those from Navarre. Our results suggest that, in both groups, the F allele of exon 2 VDR gene polymorphism may increase type 1 diabetes susceptibility.