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Herrera, A.

Publications and source records attributed to Herrera, A..

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Ethnobotanical and nutritional study of quelites sold in two traditional markets of Oaxaca, Mexico

Background.In Mexico, it is called quelites to certain edible vegetables (young plants, germ, shoots or flowers). Since pre-Hispanic times, quelites have been eaten as a source of vitamins, minerals and proteins. Now, its traditional and healthy consumption has decreased. We studied the quelites of two traditional markets in the Valles Centrales of Oaxaca state, Mexico using an ethnobotanical and nutritional approach.\n\nMethodsFrom July 2017 to July 2018, weekly ethnobotanical interviews were conducted with 26 collectors-sellers of the Zimatlan market and 36 in the Zaachila market. The vegetal supply was acquired, herborized and identified by through dichotomous keys. There were determined the proximal composition, phenolic compounds, flavonoids, antioxidant capacity and mineral content of the floral structures of two quelites types. The statistical analysis was performed through a one-way analysis of variance (ANOVA) of Tukey HSD.\n\nResultsIn two sampled markets, 23 species belonging to 11 botanical families were registered, from which leaves, branches, stems, flowers and fruits are eaten. The flowers of the species Diphysa americana (Q1) and Phaseolus coccineus (Q2) are the most used for human consumption of the communities involved in the sale of the sampled quelites. Both flowers had important amounts of proteins (2.66-3.29%) and fiber (1.66-2.43%). Q1 had higher content of phenols and flavonoids and therefore higher antioxidant capacity than Q2 (p <0.05). When we talk about Q2 minerals, it presented a greater amount of Zn, Ca and Mg in comparison to Q1 (p> 0.05).\n\nConclusionsIn local markets of the state of Oaxaca, a wide variety of quelites are usually found, where their botanical structures, such as flowers, are widely eaten. The flowers of Q1 and Q2 proved to be a rich source of proteins and bioactive compounds, as well as minerals. Showing thus to be a food alternative to enrich the human diet.

plant biology

E proteins differentially co-operate with proneural bHLH transcription factors to sharpen neurogenesis

Basic HLH proteins heterodimerize with class I HLH/E proteins to promote transcription. Here we show that E proteins differentially co-operate with proneural bHLH transcription factors sharpening their neurogeneic activity. We find that inhibiting BMP signaling or its target ID2, in the chick embryo spinal cord, impairs the neuronal production from progenitors expressing ATOH1/ASCL1, but less severely that from progenitors expressing NEUROG1/2/PTF1a. We define the mechanisms of this differential response as a dual co-operation of E proteins with proneural proteins. E proteins synergize with bHLH proteins when acting on CAGSTG motifs, thereby facilitating the neurogenic activity of ASCL1/ATOH1 which preferentially bind to such motifs. Conversely, E proteins restrict the strong neurogenic potential of NEUROG1/2 by directly inhibiting their preferential binding to CADATG motifs. Since we find this mechanism to be conserved in corticogenesis, we propose this dual co-operation of E proteins with bHLH proteins as a novel though general feature of their mechanism of action.

developmental biology

PI3K regulates intraepithelial cell positioning through Rho GTP-ases in the developing neural tube.

SUMMARY STATEMENTDuring neural tube development, PI3K pathway promotes cell survival and provides the apical-basal navigation clues that define the final location of neurons in the epithelium.\n\nSUMMARYPhosphatidylinositol 3-kinases (PI3Ks) are signal transducers of many biological processes. Class 1A PI3Ks are hetero dimers formed by a regulatory and a catalytic subunit. We have used the developing chicken neural tube (NT) to study the roles played by PI3K during the process of cell proliferation and differentiation. Notably, we have observed that in addition to its well characterized anti apoptotic activity, PI3K also plays a crucial role in intra epithelial cell positioning, and unlike its role in survival that mainly depends on AKT, the activity in cell positioning is mediated by Rho GTPase family members. Additionally, we have observed that activating mutations of PI3K that are remarkably frequent in many human cancers, cause an unrestrained basal migration of the neuroepithelial cells that end up breaking through the basal membrane invading the surrounding mesenchymal tissue. The mechanism described in this work contribute not only to acquire a greater knowledge of the intraepithelial cell positioning process, but also give new clues on how activating mutations of PI3K contribute to cell invasion during the first stages of tumour dissemination.

cell biology