In Peru, Cucurbita moschata Duchesne has a local variety called Loche, it is propagated by cuttings and little is known about its sexual reproduction. Therefore, the objective of the present work was to evaluate floral and reproductive biology in Loche from Lambayeque. The female flowers have a bigger diameter and corolla length than the male ones; however, the latter have longer pedicels and sepals. The male flowering begins before the female with the appearance of flower buds. Female flowers started anthesis process before male flowers. Likewise, during the production of flowers on average, 10 male flowers per female flower was observed. The pollen grain has a viability of 98% from anthesis and decreases to 20% in the next day. The number of average pollen grains per flower ranged between 25 125 and 31 833 and a diameter of 0.1 to 0.2 mm. The stigma is receptive for three days from anthesis. Nectar production was higher in female flowers than in male ones. The Loche presents self-pollination, cross-pollination and open pollination by insects, where the order Hymenoptera has the highest number of families with affinity to flowers and families such as Vespidae and Apidae are the most regular in visits, being the longest in stay Drosophila sp. It also presents asexual reproduction through facultative apomixis.

En el Perú, Cucurbita moschata Duchesne tiene una variedad local llamada Loche, que se propaga por esquejes y de la que se conoce muy poco sobre su reproducción sexual. Por ello, el objetivo del presente trabajo fue evaluar la biología floral y reproductiva del Loche de Lambayeque. En esta especie las flores femeninas poseen mayor diámetro y longitud de corola que las masculinas, sin embargo, estas últimas presentan pedicelos y sépalos más largos. La floración masculina inició antes que la femenina con la aparición de los botones florales. En la antesis, las flores femeninas iniciaron este proceso antes que las masculinas. Asimismo, durante la producción de flores en promedio se observó 10 flores masculinas por cada flor femenina. En relación al grano de polen, éste tiene una viabilidad del 98% desde la antesis, la que decae hasta un 20% al día siguiente. El número promedio de granos de polen por flor osciló entre 25 125 y 31 833 y el diámetro presentó de 0.1 a 0.2 mm. El estigma es receptivo durante tres días desde la antesis. La producción de néctar fue mayor en las flores femeninas que en las masculinas. El Loche presenta varios sistemas reproductivos: a nivel sexual, la geitonogamia y alogamia; y a nivel asexual, por medio de esquejes y apomixis facultativa, los cuales fueron determinados a partir de pruebas de polinización. Entre los polinizadores de C. moschata, el orden Hymenoptera tiene el mayor número de familias con afinidad por sus flores. Las familias Vespidae y Apidae son las de mayor regularidad en las visitas, siendo Drosophila sp. la de mayor duración en estancia.

Neuronal apoptosis occurs in the diabetic brain due to insulin deficiency or insulin resistance, both of which reduce the expression of stem cell factor (SCF). We investigated the possible involvement of the activation of the MAPK/ERK and/or AKT pathways in neuroprotection by SCF in diabetes. Male C57/B6 mice (20-25 g) were randomly divided into four groups of 10 animals each. The morphology of the diabetic brain in mice treated or not with insulin or SCF was evaluated by H&E staining and TUNEL. SCF, ERK1/2 and AKT were measured by Western blotting. In diabetic mice treated with insulin or SCF, there was fewer structural change and apoptosis in the cortex compared to untreated mice. The apoptosis rate of the normal group, the diabetic group receiving vehicle, the diabetic group treated with insulin, and the diabetic group treated with SCF was 0.54 ± 0.077%, 2.83 ± 0.156%, 1.86 ± 0.094%, and 1.78 ± 0.095% (mean ± SEM), respectively. SCF expression was lower in the diabetic cortex than in the normal cortex; however, insulin increased the expression of SCF in the diabetic cortex. Furthermore, expression of phosphorylated ERK1/2 and AKT was decreased in the diabetic cortex compared to the normal cortex. However, insulin or SCF could activate the phosphorylation of ERK1/2 and AKT in the diabetic cortex. The results suggest that SCF may protect the brain from apoptosis in diabetes and that the mechanism of this protection may, at least in part, involve activation of the ERK1/2 and AKT pathways. These results provide insight into the mechanisms by which SCF and insulin exert their neuroprotective effects in the diabetic brain.

Period2 is a core circadian gene, which not only maintains the circadian rhythm of cells but also regulates some organic functions. We investigated the effects of mPeriod2 (mPer2) expression on radiosensitivity in normal mouse cells exposed to 60Co-γ-rays. NIH 3T3 cells were treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) to induce endogenous mPer2 expression or transfected with pcDNA3.1(+)-mPer2 and irradiated with 60Co-γ-rays, and then analyzed by several methods such as flow cytometry, colony formation assay, RT-PCR, and immunohistochemistry. Flow cytometry and colony formation assay revealed that irradiated NIH 3T3 cells expressing high levels of mPer2 showed a lower death rate (TPA: 24 h 4.3% vs 12 h 6.8% and control 9.4%; transfection: pcDNA3.1-mPer2 3.7% vs pcDNA3.1 11.3% and control 8.2%), more proliferation and clonogenic survival (TPA: 121.7 ± 6.51 vs 66.0 ± 3.51 and 67.7 ± 7.37; transfection: 121.7 ± 6.50 vs 65.3 ± 3.51 and 69.0 ± 4.58) both when treated with TPA and transfected with mPer2. RT-PCR analysis showed an increased expression of bax, bcl-2, p53, c-myc, mre11, and nbs1, and an increased proportionality of bcl-2/bax in the irradiated cells at peak mPer2 expression compared with cells at trough mPer2 expression and control cells. However, no significant difference in rad50 expression was observed among the three groups of cells. Immunohistochemistry also showed increased protein levels of P53, BAX and proliferating cell nuclear antigen in irradiated cells with peak mPer2 levels. Thus, high expression of the circadian gene mPer2 may reduce the radiosensitivity of NIH 3T3 cells. For this effect, mPer2 may directly or indirectly regulate the expressions of cell proliferation- and apoptosis-related genes and DNA repair-related genes.