38 research outputs found

    Natural selection on plant resistance to herbivores in the native and introduced range

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    . When plants are introduced into new regions, the absence of their co-evolved natural enemies can result in lower levels of attack. As a consequence of this reduction in enemy pressure, plant performance may increase and selection for resistance to enemies may decrease. In the present study, we compared leaf damage, plant size and leaf trichome density, as well as the direction and magnitude of selection on resistance and plant size between non-native (Spain) and native (Mexico) populations of Datura stramonium. This species was introduced to Spain about five centuries ago and constitutes an ideal system to test four predictions of the enemy release hypothesis. Compared with native populations, we expected Spanish populations of D. stramonium to have (i) lower levels of foliar damage; (ii) larger plant size; (iii) lower leaf trichome density that is unrelated to foliar damage by herbivores; and (iv) weak or no selection on resistance to herbivores but strong selection on plant size. Our results showed that, on average, plants from non-native populations were significantly less damaged by herbivores, were less pubescent and were larger than those from native populations. We also detected different selection regimes on resistance and plant size between the non-native and native ranges. Positive selection on plant size was detected in both ranges (though it was higher in the non-native area), but consistent positive selection on relative resistance was detected only in the native range. Overall, we suggest that changes in selection pressure on resistance and plant size in D. stramonium in Spain are a consequence of ‘release from natural enemies’

    Evaluación histopatológica en modelo murino suplementado con creatina

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    Creatine is a natural nutrient, made up of three amino acids (glycine, arginine and methionine), it can be synthesized endogenously in the pancreas, liver and kidney, or it can also be obtained from the diet with the consumption of foods of animal origin (meat and fish), 95 percent of the creatine in the body can be located in skeletal muscle. The objective of the work was to determine histologically the effect of creatine (α-methyl guanido-acetic acid or creatine monohydrate) in a mouse model. As a methodology, an experimental, longitudinal, analytical and descriptive study was carried out, 3 groups of animals with 5 each were used, in which 3 different doses of creatine were tested for 60 days, at the end of the time they were sacrificed and anthropometric measurements were obtained. and histological sections. The results showed that there is obesity in the study groups, in terms of histology, the microscopic images observed in the control groups did not show global abnormalities in their structural morphology, indicating that the manipulation and/or exposure times did not modify the architecture of the muscle, large intestine, pancreas, liver, kidney, skin, lung, and small intestine. It can be concluded that at the doses used, creatine is safe.La creatina es un nutriente natural, formado por tres aminoácidos (glicina, arginina y metionina), se puede sintetizar endógenamente en páncreas, hígado y riñón, o también se pude obtener dentro de la dieta con el consumo de alimentos de origen animal (carnes y pescado), el 95 por ciento de la creatina en el organismo se puede localizar en el musculo esquelético. El objetivo del trabajo fue determinar histológicamente el efecto de la creatina (ácido α-metil guanido-acético o monohidrato de creatina) en modelo murino. Como metodología se realizó un estudio experimental, longitudinal, analítico y descriptivo, se utilizaron 3 grupos de animales con 5 cada uno, en los cuales durante 60 días se probaron 3 diferentes dosis de creatina, al término del tiempo se sacrificaron y se obtuvieron medidas antropométricas y cortes histológicos. Los resultados arrojaron que existe obesidad en los grupos de estudio, en cuanto a la histología las imágenes microscópicas observadas de los grupos control no mostraron anormalidades globales en su morfología estructural, indicando que la manipulación y/o los tiempos de exposición no modificaron la arquitectura del musculo, intestino grueso, páncreas, hígado, riñón, piel, pulmón e intestino delgado. Se puede concluir que a las dosis utilizadas la creatina es segura

    An AGAMOUS-related MADS-box gene, XAL1 (AGL12), regulates root meristem cell proliferation and flowering transition in Arabidopsis

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    11 pages, 5 figures, 1 table.-- PMID: 18203871 [PubMed].-- PMCID: PMC2259045.-- Supplementary information available at: http://www.plantphysiol.org/cgi/content/full/pp.107.108647/DC1MADS-box genes are key components of the networks that control the transition to flowering and flower development, but their role in vegetative development is poorly understood. This article shows that the sister gene of the AGAMOUS (AG) clade, AGL12, has an important role in root development as well as in flowering transition. We isolated three mutant alleles for AGL12, which is renamed here as XAANTAL1 (XAL1): Two alleles, xal1-1 and xal1-2, are in Columbia ecotype and xal1-3 is in Landsberg erecta ecotype. All alleles have a short-root phenotype with a smaller meristem, lower rate of cell production, and abnormal root apical meristem organization. Interestingly, we also encountered a significantly longer cell cycle in the strongest xal1 alleles with respect to wild-type plants. Expression analyses confirmed the presence of XAL1 transcripts in roots, particularly in the phloem. Moreover, XAL1beta-glucuronidase expression was specifically up-regulated by auxins in this tissue. In addition, mRNA in situ hybridization showed that XAL1 transcripts were also found in leaves and floral meristems of wild-type plants. This expression correlates with the late-flowering phenotypes of the xal1 mutants grown under long days. Transcript expression analysis suggests that XAL1 is an upstream regulator of SOC, FLOWERING LOCUS T, and LFY. We propose that XAL1 may have similar roles in both root and aerial meristems that could explain the xal1 late-flowering phenotype.This work was supported by Consejo Nacional de Ciencia y Tecnología (CONACYT), México (grant nos. CO1.41848/A–1, CO1.0538/A–1, and CO1.0435.B–1); Dirección General de Asuntos del Personal Académico (DGAPA)-Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica (PAPIIT), Universidad Nacional Autónoma de México (UNAM; grant nos. IN230002 and IX207104); and the University of California-MEXUS ECO IE 271 to E.R.A.-B. R.T.-L. was a recipient of CONACYT and DGAPA-PAPIIT-UNAM fellowships (no. IX225304). J.G.D. was supported by DGAPA-PAPIIT-UNAM (grant nos. IN210202 and IN225906) and CONACYT (grant no. 49267).Peer reviewe

    Evaluation of visible implants elastomer tags in juveniles of red octopus Octopus maya : Evaluación de implantes visibles de elastómero en juveniles de pulpo rojo Octopus maya

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    In this work, the effects of visible implant elastomer (VIE) tags on survival and body growth rate on juvenile red octopus Octopus maya from the Yucatan Peninsula were tested under controlled conditions. Juveniles with an average weight of 1.14 g were not affected by VIE within 30 days, so this methodology is suggested as a useful tool to study the life cycle aspects of this important fishery species

    A haplotype of the phosphodiesterase 4D (PDE4D) gene is associated with myocardial infarction and with cardiometabolic parameters

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    The phosphodiesterase family is involved in a wide spectrum of diseases, including ischemic stroke. However, few studies have analyzed the relationship between phosphodiesterase 4D (PDE4D) and myocardial infarction (MI). Therefore, the aim of this research was to evaluate the association of the PDE4D gene polymorphisms with MI, and with cardiometabolic parameters in the Mexican population. Six polymorphisms (rs2910829, rs1423246, rs966221, rs4502776, rs13172481, and rs6869495) were genotyped in 1023 MI patients and 1105 healthy controls. A similar distribution of the six polymorphisms was observed in both studied groups. However, after evaluating the linkage disequilibrium, we detected a risk haplotype for MI (AGAGAA; OR = 1.148; P = 0.025). In addition, the polymorphisms were associated with the presence of some clinical and metabolic parameters (central obesity, hypertriglyceridemia, Aspartate transaminase >p75, Lipoprotein (a) >30 mg/dL, TAT >p75, fatty liver, and vitamin D <30 ng/dL) in healthy controls. The results suggest that in the Mexican population, a PDE4D haplotype is associated with increased risk of developing MI, and that PDE4D polymorphisms are independently associated with the presence of cardiometabolic parameters

    Interleukin 6 (rs1800795) gene polymorphism is associated with cardiovascular diseases

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    Cardiovascular diseases (CVD) are group of complex and multifactorial pathologies, in which interleukin-6 (IL- 6) gene polymorphisms have been associated with several components of the CVD. Thus, in this study, we thoroughly reviewed and meta-analyzed evidence on the association between the IL-6 (rs1800795) gene polymorphism and CVD. We systematically searched in the PubMed, Web of Sciences, and Scopus databases. The analyses were performed using five study groups based on (1) a combined pool of the overall populations, (2) the country of birth, (3) the continent of birth, (4) the diagnosis and (5) both location (country or continent) and diagnosis. The analysis included the allelic, homozygote, heterozygote, dominant and recessive models. The meta-analysisshowed that -174G>C (rs1800795) is a risk factor for CVD (allelic: OR=1.06, CI 95%=1.02-1.10. Z p value C (rs1800795) polymorphism have an increase in the risk of coronary artery disease under the hereditary models assessed in the study. Using robust data, we found that IL-6 (rs1800795) -174G>C gene polymorphism is associated with CVD risk

    Human male gamete endocrinology: 1alpha, 25-dihydroxyvitamin D3 (1,25(OH)2D3) regulates different aspects of human sperm biology and metabolism

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    <p>Abstract</p> <p>Background</p> <p>A wider biological role of 1alpha,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the active metabolite of vitamin D3, in tissues not primarily related to mineral metabolism was suggested. Recently, we evidenced the ultrastructural localization the 1,25(OH)2D3 receptor in the human sperm. However, the 1,25(OH)2D3 action in human male reproduction has not yet been clarified.</p> <p>Methods and Results</p> <p>By RT-PCR, Western blot and Immunofluorescence techniques, we demonstrated that human sperm expresses the 1,25(OH)2D3 receptor (VDR). Besides, 25(OH)D3-1 alpha-hydroxylase, evidenced by Western blot analysis, indicated that in sperm 1,25(OH)2D3 is locally produced, highlighting the potential for autocrine-paracrine responses. 1,25(OH)2D3 through VDR, increased intracellular Ca2+ levels, motility and acrosin activity revealing an unexpected significance of this hormone in the acquisition of fertilizing ability. In sperm, 1,25(OH)2D3 through VDR, reduces triglycerides content concomitantly to the increase of lipase activity. Rapid responses stimulated by 1,25(OH)2D3 have been observed on Akt, MAPK and GSK3 implying that this secosteroid is involved in different sperm signalling pathways.</p> <p>Conclusion</p> <p>Our data extended the role of 1,25(OH)2D3 beyond its conventional physiological actions, paving the way for novel therapeutic opportunities in the treatment of the male reproduction disorders.</p

    The fatal contribution of serine protease-related genetic variants to COVID-19 outcomes

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    IntroductionSerine proteases play a critical role during SARS-CoV-2 infection. Therefore, polymorphisms of transmembrane protease serine 2 (TMPRSS2) and serpine family E member 1 (SERPINE1) could help to elucidate the contribution of variability to COVID-19 outcomes.MethodsTo evaluate the genetic variants of the genes previously associated with COVID-19 outcomes, we performed a cross-sectional study in which 1536 SARS-CoV-2-positive participants were enrolled. TMPRSS2 (rs2070788, rs75603675, rs12329760) and SERPINE1 (rs2227631, rs2227667, rs2070682, rs2227692) were genotyped using the Open Array Platform. The association of polymorphisms with disease outcomes was determined by logistic regression analysis adjusted for covariates (age, sex, hypertension, type 2 diabetes, and obesity).ResultsAccording to our codominant model, the GA genotype of rs2227667 (OR=0.55; 95% CI = 0.36-0.84; p=0.006) and the AG genotype of rs2227667 (OR=0.59; 95% CI = 0.38-0.91; p=0.02) of SERPINE1 played a protective role against disease. However, the rs2227692 T allele and TT genotype SERPINE1 (OR=1.45; 95% CI = 1.11-1.91; p=0.006; OR=2.08; 95% CI = 1.22-3.57; p=0.007; respectively) were associated with a decreased risk of death. Similarly, the rs75603675 AA genotype TMPRSS2 had an OR of 1.97 (95% CI = 1.07-3.6; p=0.03) for deceased patients. Finally, the rs2227692 T allele SERPINE1 was associated with increased D-dimer levels (OR=1.24; 95% CI = 1.03-1.48; p=0.02).DiscussionOur data suggest that the rs75603675 TMPRSS2 and rs2227692 SERPINE1 polymorphisms are associated with a poor outcome. Additionally, rs2227692 SERPINE1 could participate in hypercoagulable conditions in critical COVID-19 patients, and this genetic variant could contribute to the identification of new pharmacological targets and treatment strategies to block the inhibition of TMPRSS2 entry into SARS-CoV-2
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