342 research outputs found
Satellite Remote Sensing of Coral Reef Habitats Mapping in Shallow Waters at Banco Chinchorro Reefs, México: A Classification Approach
Assessing genetic structuring for endangered Chelonia mydas (Testudines: Cheloniidae) in southwest Cuba using microsatellites.
Understanding the population genetic structure of the species is essential for determining the possible management units (UM) and their conservation and/or sustainable exploitation with it. Chelonia mydas is recognized as an endangered philopatric turtle. This work aims to describe the population structure of the green turtle in southwestern Cuba through traditional analytical approaches and allocation methods. The collections were made between 1998 and 2007 on five beaches in the Cuban southwest. Seven microsatellite loci from 149 individuals were amplified and genetic variability parameters were calculated. The population structure was inferred through the use of Wright's F, Analysis of Molecular Variance (AMOVA), and population assignment algorithms based on Bayesian analysis (STRUCTURE) and factorization of sparse non-negative matrices (implemented in R). Most of the loci were not in Hardy-Weinberg equilibrium, and several presented linkage disequilibrium. The AMOVA and differentiation statistics suggest the presence of structure at the geographical level analyzed. The highest value of ΔK and the lowest value of cross-entropy were reached for K = 2, a result that suggests that in southwestern Cuba there is the contribution of two ancestral populations of Chelonia mydas. Relative migration estimates indicate active genetic exchange between nesting colonies in southwestern Cuba.Este estudio ha recibido fondos del programa de Doctorado UNAM-UH y TWAS.
We thank the protected areas administration, and the forest rangers protecting and monitoring the sea turtle nesting areas; the Ministry of Science, Technology, and Environment for the authorization to access natural areas and for their support of the monitoring work; to all workers and volunteers for their effort to protect sea turtles in Cuba. We also thank Laboratorio de Genética of Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología UNAM and Centro de Investigaciones en Ecosistemas in UNAM, Morelia, for facilities and equipment used in our genetic analyses
Identification of non-tuberculous mycobacteria isolated from opossum (Didelphis virginiana) lymph nodes and characterisation of lesions
The aim of this study was to investigate the presence of NTM in the lymph nodes of opossums (D. virginiana) and to characterise the microscopic changes in affected tissue. Retropharyngeal and tracheobronchial lymph nodes were collected postmortem from 18 opossums in the state of Colima, Mexico in 2013. The lymph nodes were also cultured for mycobacterial organisms and processed for histopathological examination. Bacteriological cultures yielded 5/18X100 (28%) isolates of NTM, which were subsequently identified as M. terrae, M. szulgai, M. gastri and M. asiaticum. Microscopic examination of the affected nodes revealed a necrotic granulomatous lymphadenitis (3/60%) composed of histiocytes, epithelioid cells and giant cells with intralesional alcoholresistant acid bacteria. An association between the sex of the opossum and the presence of NTM was observed. To our knowledge, this is the first report of NTM isolation in opossums with granulomatous lymphadenitis in Mexico
Rat adipose tissue secretome differential analysis from different anatomical locations
Comunicaciones a congreso
KIR+ CD8+ T Lymphocytes in Cancer Immunosurveillance and Patient Survival: Gene Expression Profiling
Killer-cell immunoglobulin-like receptors (KIR) are molecules expressed by the most important cells of the immune system for cancer immune vigilance, natural killer (NK) and effector T cells. In this manuscript we study the role that cytotoxic CD8+ T cells expressing KIR receptors could play in cancer immune surveillance. With this objective, frequencies of different KIR+ CD8+ T cell subsets are correlated with the overall survival of patients with melanoma, ovarian and bladder carcinomas. In addition, the gene expression profile of KIR+ CD8+ T cell subsets related to the survival of patients is studied with the aim of discovering new therapeutic targets, so that the outcome of patients with cancer can be improved.
Killer-cell immunoglobulin-like receptors (KIR) are expressed by natural killer (NK) and effector T cells. Although KIR+ T cells accumulate in oncologic patients, their role in cancer immune response remains elusive. This study explored the role of KIR+CD8+ T cells in cancer immunosurveillance by analyzing their frequency at diagnosis in the blood of 249 patients (80 melanomas, 80 bladder cancers, and 89 ovarian cancers), their relationship with overall survival (OS) of patients, and their gene expression profiles. KIR2DL1+ CD8+ T cells expanded in the presence of HLA-C2-ligands in patients who survived, but it did not in patients who died. In contrast, presence of HLA-C1-ligands was associated with dose-dependent expansions of KIR2DL2/S2+ CD8+ T cells and with shorter OS. KIR interactions with their specific ligands profoundly impacted CD8+ T cell expression profiles, involving multiple signaling pathways, effector functions, the secretome, and consequently, the cellular microenvironment, which could impact their cancer immunosurveillance capacities. KIR2DL1/S1+ CD8+ T cells showed a gene expression signature related to efficient tumor immunosurveillance, whereas KIR2DL2/L3/S2+CD8+ T cells showed transcriptomic profiles related to suppressive anti-tumor responses. These results could be the basis for the discovery of new therapeutic targets so that the outcome of patients with cancer can be improved
Atenuación de una cepa de Babesia argentina (Babesia bovis) de origen colombiano.
Una cepa de Babesia argentina (Babesia bovis), aislada en Montería, fué atenuada por pasajes contínuos en terrenos esplenectomizados. El comportamiento atenuado se empezó a observar a partir del pasaje no. 23. Un estudio estadístico comparativo realizado con tres grupos de animales mostró diferencias significativas entre los grupos. Un grupo de 20 novillos fué inoculado con 10 a la 10 parásitos de la cepa virulenta de Babesia argentina (pasaje no. 6). Otro grupo de 30 novillos fué inoculado con 10 a la 10 parásitos de la cepa atenuada de Babesia argentina (pasaje no. 27). Otro grupo de 10 novillos, no fué inoculado, fué dejado como control. De los 20 novillos inoculados con la cepa virulenta, 19 mostraron síntomas clínicos de babesiosis aguda y 9 animales murieron entre los días 11 a 14 post-inoculación (P.I.). Ninguno de los 30 animales del grupo inoculado con la cepa atenuada mostró síntomas clínicos de la enfermedad, se observó únicamente ligera disminución del hematocrito al día 14 P.I. (menos 6.5 por ciento) y leve aumento de la temperatura al día 11 P.I. (más 0.32 grados centígrados). Las implicaciones de la utilización de esta cepa atenuada para el control y la prevención de la babesiosis bovina son obvia
Secondary Infall in the Seyfert\u27s Sextet: A Plausible Way out of the Short Crossing Time Paradox
We used integral field spectroscopy from CALIFA DR3 and multiwavelength publicly available data to investigate the star formation histories of galaxies in the Seyfert\u27s Sextet (SS; HCG 79). The galaxies H79a, H79b, H79c, and H79f have low star formation rates despite showing strong signs of interaction. By exploring their individual specific star formation histories, we identified three earlier episodes of strong star formation common to these four galaxies. We use the last two episodes as markers of the epochs when the galaxies were crossing. We suggest that after the first turnaround, initially gas-rich galaxies crossed for the first time, consuming most of their gas. Hence, after the second turnaround most mergers from second crossings would be mixed or dry. The exception would be gas-rich galaxies intruding for the first time. Therefore, we suggest that SS galaxies have survived one crossing during a Hubble time. Strong Balmer absorption lines and the presence of counter-rotating disks provide independent bounds to the second and first crossing, respectively. This scenario provides a plausible way out of the short crossing time paradox
Secondary Infall in the Seyfert's Sextet:A Plausible Way Out of the Short Crossing Time Paradox
We used integral field spectroscopy from CALIFA DR3 and multiwavelength
publicly-available data to investigate the star-formation histories of galaxies
in the Seyfert's Sextet (SS, HCG 79). The galaxies H79a, H79b, H79c, and H79f
have low star-formation rates despite showing strong signs of interaction. By
exploring their individual specific star formation histories (sSFH), we
identified three earlier episodes of strong star formation common to these four
galaxies. We use the last two episodes as markers of the epochs when the
galaxies were crossing. We suggest that after the first turn-around, initially
gas-rich galaxies crossed for the first time, consuming most of their gas.
Hence after the second turn-around most mergers from second crossings would be
mixed or dry. The exception would be gas-rich galaxies intruding for the first
time. Therefore, we suggest that SS galaxies have survived one crossing during
a Hubble time. Strong Balmer absorption lines and the presence of
counter-rotating disks provide independent bounds to the second and first
crossing, respectively. This scenario provides a plausible way out of the short
crossing time paradox.Comment: 21 pages, 5 figues, accepted for publication in ApJ Letter
Assessing genetic structuring for endangered "Chelonia mydas" (Testudines: Cheloniidae) in southwest Cuba using microsatellites
Understanding the population genetic structure of the species is essential for determining the possible management units (UM) and their conservation and/or sustainable exploitation with it. Chelonia mydas is recognized as an endangered philopatric turtle. This work aims to describe the population structure of the green turtle in southwestern Cuba through traditional analytical approaches and allocation methods. The collections were made between 1998 and 2007 on five beaches in the Cuban southwest. Seven microsatellite loci from 149 individuals were amplified and genetic variability parameters were calculated. The population structure was inferred through the use of Wright's F, Analysis of Molecular Variance (AMOVA), and population assignment algorithms based on Bayesian analysis (STRUCTURE) and factorization of sparse non-negative matrices (implemented in R). Most of the loci were not in Hardy-Weinberg equilibrium, and several presented linkage disequilibrium. The AMOVA and differentiation statistics suggest the presence of structure at the geographical level analyzed. The highest value of ΔK and the lowest value of cross-entropy were reached for K = 2, a result that suggests that in southwestern Cuba there is the contribution of two ancestral populations of Chelonia mydas. Relative migration estimates indicate active genetic exchange between nesting colonies in southwestern Cuba.
Received: 07.02.2022 Accepted: 09.12.2022
Editor: Erik García-Machad
DNA methylation in genes of longevity‐regulating pathways: association with obesity and metabolic complications
Aging is the main risk factor for most chronic diseases. Epigenetic mechanisms, such as DNA methylation
(DNAm) plays a pivotal role in the regulation of physiological responses that can vary along lifespan. The aim of
this research was to analyze the association between leukocyte DNAm in genes involved in longevity and the
occurrence of obesity and related metabolic alterations in an adult population. Subjects from the MENA cohort
(n=474) were categorized according to age () and the presence of metabolic alterations: increased
waist circumference, hypercholesterolemia, insulin resistance, and metabolic syndrome. The methylation levels
of 58 CpG sites located at genes involved in longevity‐regulating pathways were strongly correlated (FDR‐
adjusted< 0.0001) with BMI. Fifteen of them were differentially methylated (p<0.05) between younger and
older subjects that exhibited at least one metabolic alteration. Six of these CpG sites, located at MTOR
(cg08862778), ULK1 (cg07199894), ADCY6 (cg11658986), IGF1R (cg01284192), CREB5 (cg11301281), and RELA
(cg08128650), were common to the metabolic traits, and CREB5, RELA, and ULK1 were statistically associated
with age. In summary, leukocyte DNAm levels of several CpG sites located at genes involved in longevity‐
regulating pathways were associated with obesity and metabolic syndrome traits, suggesting a role of DNAm in
aging‐related metabolic alterations
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