Transcriptomic analysis of bell pepper (Capsicum annuum L.) revealing key mechanisms in response to low temperature stress.

BACKGROUND: Bell pepper (Capsicum annuum L.) is one of the most economically and nutritionally important vegetables worldwide. However, its production can be affected by various abiotic stresses, such as low temperature. This causes various biochemical, morphological and molecular changes affecting membrane lipid composition, photosynthetic pigments, accumulation of free sugars and proline, secondary metabolism, as well as a change in gene expression. However, the mechanism of molecular response to this type of stress has not yet been elucidated. METHODS AND RESULTS: To further investigate the response mechanism to this abiotic stress, we performed an RNA-Seq transcriptomic analysis to obtain the transcriptomic profile of Capsicum annuum exposed to low temperature stress, where libraries were constructed from reads of control and low temperature stress samples, varying on average per treatment from 22,952,190.5-27,305,327 paired reads ranging in size from 30 to 150 bp. The number of differentially expressed genes (DEGs) for each treatment was 388, 417 and 664 at T-17 h, T-22 h and T-41 h, respectively, identifying 58 up-regulated genes and 169 down-regulated genes shared among the three exposure times. Likewise, 23 DEGs encoding TFs were identified at T-17 h, 30 DEGs at T-22 h and 47 DEGs at T-42 h, respectively. GO analysis revealed that DEGs were involved in catalytic activity, response to temperature stimulus, oxidoreductase activity, stress response, phosphate ion transport and response to abscisic acid. KEGG pathway analysis identified that DEGs were related to flavonoid biosynthesis, alkaloid biosynthesis and plant circadian rhythm pathways in the case of up-regulated genes, while in the case of down-regulated genes, they pertained to MAPK signaling and plant hormone signal transduction pathways, present at all the three time points of low temperature exposure. Validation of the transcriptomic method was performed by evaluation of five DEGs by quantitative polymerase chain reaction (q-PCR). CONCLUSIONS: The data obtained in the present study provide new insights into the transcriptome profiles of Capsicum annuum stem in response to low temperature stress. The data generated may be useful for the identification of key candidate genes and molecular mechanisms involved in response to this type of stress.

Hatching Success Rather Than Temperature-Dependent Sex Determination as the Main Driver of Olive Ridley (Lepidochelys olivacea) Nesting Activity in the Pacific Coast of Central America.

In marine turtles, sex is determined during a precise period during incubation: males are produced at lower temperatures and females at higher temperatures, a phenomenon called temperature-dependent sex determination. Nest temperature depends on many factors, including solar radiation. Albedo is the measure of the proportion of reflected solar radiation, and in terms of sand color, black sand absorbs the most energy, while white sand reflects more solar radiation. Based on this observation, darker sand beaches with higher temperatures should produce more females. As marine turtles show a high degree of philopatry, including natal homing, dark beaches should also produce more female hatchlings that return to nest when mature. When sand color is heterogeneous in a region, we hypothesize that darker beaches would have the most nests. Nevertheless, the high incubation temperature on beaches with a low albedo may result in low hatching success. Using Google Earth images and the SWOT database of nesting olive ridleys (Lepidochelys olivacea) in the Pacific coast of Mexico and Central America, we modeled sand color and nesting activity to test the hypothesis that darker beaches host larger concentrations of females because of feminization on darker beaches and female philopatry. We found the opposite result: the lower hatching success at beaches with a lower albedo could be the main driver of nesting activity heterogeneity for olive ridleys in Central America.

Relación entre la temperatura de incubación y la asimetría del carapacho de neonatos de Lepidochelys olivacea incubados en el Área de Usos Múltiples Hawaii (AUMH), Santa Rosa, Guatemala / Relationship between incubation temperature and carapace asymmetry of neonates of Lepidochelys olivacea incubated in the Area of Multiple Use Hawaii (AUMH), Santa Rosa, Guatemala

Los embriones de tortugas marinas son susceptibles a perturbaciones ambientales, las cuales se traducen en anomalías en su fenotipo. Uno de los principales parámetros para la medición de estas perturbaciones es la asimetría en los carapachos (caparazones), que puede ser obtenida a través del Índice de Inestabilidad de Desarrollo (DIx, por sus siglas en inglés). La temperatura juega un rol importante, influenciando no solo en la futura supervivencia de los neonatos en temperaturas extremas (altas o bajas), sino en atributos específicos, tales como la determinación del sexo, o incluso puede ser la causa del incremento en el número de apéndices dérmicos (escudos) sobre la parte dorsal del carapacho. Este estudio evaluó la relación entre la temperatura de incubación con la asimetría de carapacho de los neonatos de Lepidochelys olivacea incubados en condiciones relocalizadas en el tortugario del Área de Usos Múltiples Hawaii en Santa Rosa, Guatemala. Para lograrlo, se replicaron las condiciones de anidación seleccionadas por las hembras anidadoras en nidos relocalizados, utilizando dispositivos termosensitivos para la toma de la temperatura durante el período de incubación. A través del cálculo del DIx en 210 neonatos, y mediante las pruebas de correlación de Kendall y Jockheere-Terpstra, se obtuvo que en valores de temperaturas extremas tanto altas (Kendall tau = .23, p < .001; JT = 2,891, p < .001), como bajas (Kendall tau u= -.21, p < .001; JT = 5,005, p < .001), así como en altos rangos de variación durante el período de desarrollo embrionario (Kendall tau = .23, p < .001; JT = 6,619, p < .05), los neonatos presentan una mayor asimetría.

Sea turtle embryos are susceptible to environmental disturbances, which result in abnormalities in their phenotype. One of the main parameters for measuring these disturbances is the asymmetry in the carapaces, which can be obtained through the Developmental Instability Index (DIx). Temperature plays an important role, influencing not only the future survival of hatchlings in extreme temperatures (high or low), but also specific attributes, such as sex determination, or it can even be the cause of the increase in the number of dermal appendages (shields) on the dorsal part of the carapace. This aimed to evaluate the relationship between incubation temperature and carapace asymmetry of Lepidochelys olivacea hatchlings incubated in relocated conditions in the Hawaii Multiple Use Area turtle rookery in Santa Rosa, Guatemala. To achieve this, the nesting conditions selected by the nesting females were replicated in relocated nests, using thermosensitive devices to measure the temperature during the incubation period. rough the calculation of DIx in 210 hatchlings, and using Kendall and Jockheere-Terpstra correlation tests, it was obtained that hatchlings present greater asymmetry in values of extreme temperatures, for both, high (Kendall: p<.05, tau = .232 ; JT p<.05, JT=2891) and low (Kendall: p<.05, tau= -.211 ; JT p<.05, JT=5005); as well as in high ranges of variation (Kendall: p<.05, tau= .231 ; JT p<.05, JT=6619), during the embryonic development period

Relación entre el tamaño de la tortuga anidadora y el número de huevos puestos por nido por parlama (Lepidochelys olivacea, Eschscholtz, 1829) en el Área de Usos Múltiples Hawaii, Santa Rosa, Guatemala / Relationship between the size of the nesting turtle and the number of eggs laid per nest per parlama (Lepidochelys olivacea, Eschscholtz, 1829) in the multi-use area Hawaii, Santa Rosa

Las tortugas marinas pasan toda su vida en el océano, regresando a las playas únicamente en el momento en el que anidan. La parlama (Lepidochelys olivacea) es una de las especies que anida frecuentemente en el Pacífico de Guatemala. Sin embargo, hace falta información tanto de generalidades de los nidos de parlama como de la biología de anidación de las mismas en el país. Es por eso que se buscó: 1) determinar si existe una relación entre el tamaño de la parlama (ancho curvo del caparazón) y el número de huevos puestos en cada nido; y 2) de explorar el tipo de relación existente entre el tamaño de la parlama (ancho curvo de caparazón) y el número de huevos con el momento (día dentro de la temporada) donde los huevos fueron puestos. Este estudio fue de orden descriptivo y exploratorio, en donde se midió a 74 hembras que anidaron de junio a octubre del 2017 en el Área Protegida de Usos Múltiples Hawaii, Departamento de Santa Rosa. Cabe resaltar que en Guatemala no hay datos cualitativos ni cuantitativos sobre tortugas anidadoras, por lo que es el primer estudio de esta naturaleza. Se obtuvo un tamaño promedio (desviación estándar) del ancho curvo del caparazón de 70.7cm (Desviación estándar: 2.60), IC 95 % [63 a 77cm] y un promedio de 92 huevos (D.E: 15.67), IC 95 % [59 a 120 huevos] puestos por nido. Se desarrolló un modelo lineal generalizado (3.715e+00x + 1.670e-04 -4.932e-06; p= 1.12e-3; AICc=617.14), demostrando que el ancho curvo del caparazón de la tortuga anidadora y la fecha en la que los huevos fueron puestos tienen una relación directa con el número de huevos puestos por cada tortuga anidadora. El ancho curvo del caparazón presenta una relación directa con el número de huevos. Mientras que el momento de anidación (día) presenta un efecto polinomial de segundo orden, lo cual lleva a un incremento en el número de huevos conforme avanza la temporada de anidación, y resulta en un pico a la mitad de la temporada de anidación con un patrón de descenso hacia el final de la misma.

Sea turtles spend their entire lives in the ocean, returning to the beaches only at the time they nest. The olive ridley (Lepidochelys olivacea) is one of the species that frequently nest in the Pacific of Guatemala. However, information is needed on both the generalities of sea turtle nesting behavior and the nesting biology of the turtles in the country, so it was sought to 1) determine the relationship between the size of the turtle and the number of eggs in each nest; and 2) explore what type of relationship exists between the size of the turtle and the number of eggs, with the moment (day during the nesting season) when the eggs were layed. This first descriptive and exploratory study measured 74 females that nested between the months of June to October in 2017 in the Multiple Use Area Hawaii, Santa Rosa, Guatemala. An average carapace width of 70.7cm (Standar deviation: 2.60; 95% CI of [63 to 77cm]) was obtained and an average of 92 eggs (SD: 15.67; 95% CI of [59 to 120]) per nest. A Generalized Linear Model was made and demonstrated that the width of the carapace of the nesting female and the date on which the eggs were laid have a direct relationship with the number of eggs laid by each nesting turtle (3.715e+00x + 1.670e-04 -4.932e-06; p= 1.12e-3 ; AICc=617.14). The width of the carapace has a direct relationship with the number of eggs, while the moment (day during nesting season) has a second-order polynomial effect, which leads to an increase in the number of eggs as the nesting season progresses, and results in a peak half of the nesting season with a pattern of decline towards the end of it.

Recent advances on the estimation of the thermal reaction norm for sex ratios.

Temperature-dependent sex determination, or TSD, is a widespread phenomenon in reptiles. The shape of the relationship between constant incubation temperature and sex ratio defines the TSD pattern. The TSD pattern is considered a life-history parameter important for conservation because the wider the range of temperatures producing both sexes, the more resilient the species is to climate change impacts. We review the different published equations and methodologies that have been used to model TSD patterns. We describe a new flexible model that allows for an asymmetrical pattern around the pivotal temperature, which is the constant temperature producing both sexes in equal proportions. We show that Metropolis-Hastings with Markov chain produced by a Monte Carlo process has many advantages compared to maximum likelihood and is preferred. Finally, we apply the models to results from incubation experiments using eggs from the marine turtle Lepidochelys olivacea originating in Northeast Indian, East Pacific, and West Atlantic Regional Management Units (RMUs) and find large differences in pivotal temperatures but not in transitional ranges of temperatures.

Resultados y experiencias de la vigilancia nacionalde meningitis bacteriana en Cuba / Resultados y experiencias de la vigilancia nacional

Objetivos: Desde 1998 se implementó en Cuba un nuevo sistema de vigilancia nacional de meningitis bacteriana (VNMB) con el objetivo de lograr información en correspondencia con el desarrollo científico actual y las exigencias del programa nacional de prevención y control de estas infecciones. Resultados: Este sistema permitió medir el impacto de la vacuna contra H. influenzae tipo b (Hib) en 1999 sin necesidad de un proyecto y gastos adicionales, demostrando la reducción inmediata de la incidencia (52por ciento). Hasta el 2002 fueron reportados 82 niños < 5 años de los cuales 61(74,4por ciento) no estaban vacunados. Entre los vacunados hubo 14 (66,7por ciento) con una sola dosis aplicada.A partir de esta intervención S. pneumoniae resultó el principal agente causal de meningitis. Los serogrupos/ serotipos más frecuentes han sido 19, 6, 14, 18, 1, 7 y 23, mostrando un 40por ciento de susceptibilidad disminuida a la penicilina. Por primera vez identificamos: - fuerte asociación (RR > 20) de los estudiantes internos de primaria con la enfermedad, - incidencia elevada entre amas de casa (> 2/100 000) y jubilados (> 8/100 000), - fuerte asociación (Razón de disparidad > 20) de la muerte con jubilados y amas de casa en el análisis multivariado. Los resultados microbiológicos posibilitaron la caracterización de agentes y la política antibiótica más adecuada. La letalidad general de la meningitis neumocócica fue > 32 por ciento y fundamentalmente en ancianos. Conclusiones: LaVNMB aportó novedosa información clínico - epidemiológica y microbiológica, permitiendo ampliar el marco integral de los conocimientos y garantizando acciones más efectivas y eficientes en un proyecto multidisciplinario e intersectorial generalizado (AU)