Dr. Maria-Elena Torres-Padilla’s research is focused on how cell fate arises from a single-cell embryo, the fertilized egg or zygote. After the initial divisions, cell potency becomes restricted, originating the first cell lineage fates. She studies how epigenetic information controls transitions in cell identity and cellular reprogramming during embryonic development. Currently, she is the founding Director of the Institute of Epigenetics and Stem Cells, Helmholtz Centre, and Professor of Stem Cell Biology at the LMU in Munich. In this interview, Dr. Maria-Elena Torres-Padilla talks to us about her beginnings in the biology field in Mexico. She also tells us about how she became interested in the control of genome regulation within the nucleus during the transition from totipotency to pluripotency and how the control of gene regulation and chromatin organization during the early stages of cell fate decision in the one-cell embryo occurs. She considers that science has no borders; visiting Mexico gives her the possibility to discuss her work with colleagues and the new generation of students trained in Mexico.

Shaping the vertebrate eye requires evagination of the optic vesicles. These vesicles subsequently fold into optic cups prior to undergoing neurogenesis and allocating a population of late progenitors at the margin of the eye. mab21l2 encodes a protein of unknown biological function expressed in the developing optic vesicles, and loss of mab21l2 function results in malformed eyes. The bases of these defects are, however, poorly understood.

To further study mab21l2 we used CRISPR/Cas9 to generate a new zebrafish mutant allele (mab21l2

). We characterized eye morphogenesis and neurogenesis upon loss of mab21l2 function using tissue/cell-type-specific transgenes and immunostaining, in situ hybridization and bromodeoxyuridine incorporation.

mab21l2

eyes fail to grow properly and display an excess of progenitors in the ciliary marginal zone. The expression of a transgene reporter for the vsx2 gene -a conserved marker for retinal progenitors- was delayed in mutant eyes and accompanied by disruptions in theyses supporting the role of mab21l2 in coordinating morphogenesis and differentiation in developing eyes.Molecular oxygen (O2), reactive oxygen species (ROS), and associated redox networks are cornerstones of aerobic life, these molecules and networks have gained recognition as fundamental players in mechanisms that regulate the development of multicellular organisms. First, we present a brief review in which we provide a historical description of some relevant discoveries that led to this recognition. We also discuss that despite its abundance in nature, oxygen is a limiting factor, and its high availability variation impacted the evolution of adaptive mechanisms to guarantee the proper development of diverse species under such extreme environments. read more Finally, some examples when oxygen and ROS were identified as relevant for the control of developmental processes are discussed. We take into account not only the current knowledge on animal redox developmental biology, but also briefly discuss potential scenarios on the origin and evolution of redox developmental mechanisms and the importance of the ever-changing environment.The cell differentiation of the musculoskeletal system is highly coordinated during limb development. In the distal-most region of the limb, the WNT and FGF signaling released from the apical ectodermal ridge maintain the mesenchymal cells in the undifferentiated stage. Once the cells stop receiving WNT and FGF signaling, they respond to differentiation signals. Particularly during tendon development, the mesenchymal cells enter the cell differentiation program once Scleraxis (Scx) gene expression occurs. Among the signals that trigger the cell differentiation programs, TGFβ signaling has been closely involved in tendon differentiation. However, whether the Scx gene expression depends merely on TGFβ signaling or other signals is still not fully understood. In the present study, considering that WNT/β catenin is an inhibitory signal of cell differentiation, we speculated possible antagonistic or additive effects between canonical Wnt/β catenin and TGFβ/SMAD signaling pathways to control the Scx gene expression. According to our results, the blockade of WNT/β catenin promoted the Scx gene expression. In contrast, the inhibition of TGFβ/SMAD signaling did not maintain the Scx gene expression. Interestingly, the blockade of both WNT/β-catenin and TGFβ/SMAD signaling at the same time promoted the Scx gene expression. Thus, as our results suggest, the inhibition of WNT/β signaling is necessary and sufficient to induce Scx gene expression.For over 100 years, the vertebrate eye has been an important model system to understand cell induction, cell shape change, and morphogenesis during development. In the past, most of the studies examined histological changes to detect the presence of induction mechanisms, but the advancement of molecular biology techniques has made exploring the genetic mechanisms behind lens development possible. Despite the particular emphasis given to the induction of the lens placode, there are still many aspects of the cell biology of lens morphogenesis to be explored. Here, we will revisit the classical detailed description of early lens morphological changes, correlating it with the cell biology mechanisms and with the molecules and signaling pathways identified up to now in chick and mouse embryos. A detailed description of lens development stages helps better understand the timeline of the events involved in early lens morphogenesis. We then point to some key questions that are still open.Elysia diomedea varies in adult size and color across its geographical distribution in Ecuador. Because of morphological variation and the absence of genetic information for this species in Ecuador, we analyzed mtDNA sequences in three populations (Ballenita, La Cabuya, and Mompiche) and confirmed that (1) individuals from the three locations belonged to E. diomedea and (2) that there was no population structure that could explain their morphological differences. Next, we analyzed general aspects about the reproductive biology and embryology of this species. Live slugs from the Ballenita population were maintained and reproduced ex situ. Egg ribbons and embryos were fixed and observed by brightfield and confocal microscopy. We observed a single embryo per capsule, 98 embryos per mm2 of egg ribbon, and compared the cleavage pattern of this species to other heterobranchs and spiralians. E. diomedea early development was characterized by a slight unequal first cleavage, occurrence of a 3-cell stage in the second cleavage, and the formation of an enlarged second quartet of micromeres.