International Journal of Developmental Biology最新文献

The molecular expression profiles of zebrafish ep2a and ep4b have not been defined to date. Phylogenetic trees of EP2a and EP4b in zebrafish and other species revealed that human EP4 and zebrafish EP4b were more closely related than EP2a. Zebrafish EP2a is a 281 amino acid protein which shares high identity with that of human (43%), mouse (44%), rat (43%), dog (44%), cattle (41%), and chicken (41%). Zebrafish EP4b encoded a 497 amino acid precursor with high amino acid identity to that of mammals, including human (57%), mouse (54%), rat (55%), dog (55%), cattle (56%), and chicken (54%). Whole-mount in situ hybridization revealed that ep2a was robustly expressed in the anterior four somites at the 10-somites stages, but was absent in the somites at 19 hpf. It was observed again in the pronephric duct at 24 hpf, in the intermediate cell mass located in the trunk, and in the rostral blood island at 30 hpf. Ep2a was also expressed in the notochord at 48 hpf. During somitogenesis, ep4b was highly expressed in the eyes, somites, and the trunk neural crest. From 30 to 48 hpf, ep4b could be detected in the posterior cardinal vein and the neighboring inner cell mass. From these data we conclude that ep2a and ep4b are conserved in vertebrates and that the presence of ep2a and ep4b transcripts during developmental stages infers their role during early zebrafish larval development. In addition, the variable expression of the two receptor isoforms was strongly suggestive of divergent roles of molecular regulation.

Background: The specific effect of SV40T on neurocytes has seldom been investigated by the researchers. We transfected Schwann cells (SCs) that did not have differentiation ability with MPH 86 plasmid containing SV40T, in order to explore the effects of SV40T on Schwann cells.

Methods: SCs were transfected with MPH 86 plasmid carrying the SV40T gene and cultured in different media, and also co-cultured with neural stem cells (NSCs). In our study, SCs overexpressing SV40T were defined as SV40T-SCs. The proliferation of these cells was detected by WST-1, and the expression of different biomarkers was analyzed by qPCR and immunohistochemistry.

Results: SV40T induced the characteristics of NSCs, such as the ability to grow in suspension, form spheroid colonies and proliferate rapidly, in the SCs, which were reversed by knocking out SV40T by the Flip-adenovirus. In addition, SV40T up-regulated the expressions of neural crest-associated markers Nestin, Pax3 and Slug, and down-regulated S100b as well as the markers of mature SCs MBP, GFAP and Olig1/2. These cells also expressed NSC markers like Nestin, Sox2, CD133 and SSEA-1, as well as early development markers of embryonic stem cells (ESCs) like BMP4, c-Myc, OCT4 and Gbx2. Co-culturing with NSCs induced differentiation of the SV40T-SCs into neuronal and glial cells.

Conclusions: SV40T reprograms Schwann cells to stem-like cells at the stage of neural crest cells (NCCs) that can differentiate to neurocytes.

The UNESCO Chair in Developmental Biology started in 1998, at the Institute of Biomedical Sciences of the Federal University of Rio de Janeiro, in Brazil. This Chair was a Brazilian-French initiative led by Professor Vivaldo Moura Neto and Professor Nicole Le Douarin, one of the most inspiring Developmental Biologists of the 20^th and 21^st centuries. The UNESCO Chair wanted to stimulate interest in Developmental Biology among Brazilian students and scientists by organizing annual international courses on Evolution and Developmental Biology at an advanced level. At the Federal University of Rio de Janeiro, the UNESCO Chair established an international laboratory for the permanent training of researchers and the development of research programs in Developmental Biology and related areas. Moreover, the program aimed at establishing an international network connecting Brazilian Universities and research centers in Latin America and Europe. The advanced hands-on courses, symposiums, and workshops promoted by this Chair inspired the careers of many young scientists. They generated new lines of research in Developmental Biology using a variety of animal models. This review does not intend to bring up all the historical events that marked the beginning of Developmental Biology in Brazil. Instead, it will be dedicated to highlighting one specific initiative that inspired a new generation of Developmental Biologists who established important research lines and contributed to the advance of this scientific field in Brazil.

This review highlights the work that my research group has been developing, together with international collaborators, during the last decade. Since we were able to establish the Xenopus laevis experimental model in Brazil, we have been focused on understanding early embryonic patterns regarding neural induction and axes establishment. In this context, the Wnt pathway appears as a major player and has been much explored by us and other research groups. Here, we chose to review three published works which we consider to be landmarks within the course of our research and also within the history of modern findings regarding neural induction and patterning. We intend to show how our series of discoveries, when painted together, tells a story that covers crucial developmental windows of early differentiation paths of anterior neural tissue: 1. establishing the head organizer in contrast to the trunk organizer in the early gastrula; 2. deciding between neural ectoderm and epidermis ectoderm at the blastula/gastrula stages, and 3. the gathering of prechordal unique properties in the late gastrula/early neurula.

Fish present remarkable malleability regarding gonadal sex fate. This phenotypic plasticity enables an organism to adapt to changes in the environment by responding with different phenotypes. The gonad and the brain present this extraordinary plasticity. These organs are involved in the response to environmental stressors to direct gonadal fate, inducing sex change or sex reversal in hermaphroditic and gonochoristic fish, respectively. The presence of such molecular and endocrine plasticity gives this group a large repertoire of possibilities against a continuously changing environment, resulting in the highest radiation of reproduction strategies described in vertebrates. In this review, we provide a broad and comparative view of tremendous radiation of sex determination mechanisms to direct gonadal fate. New results have established that the driving mechanism involves early response to environmental stressors by the brain plus high plasticity of gonadal differentiation and androgens as by-products of stress inactivation. In addition to the stress axis, two other major axes - the hypothalamic-pituitary-gonadal axis and the hypothalamic-pituitary-thyroid axis, which are well known for their participation in the regulation of reproduction - have been proposed to reinforce brain-gonadal interrelationships in the fate of the gonad.

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 the fact 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. Finally, some examples of 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.

There is growing demand for learning developmental biology in Latin America and a need for advanced students to interact with world leaders of this discipline. This article summarizes some of the efforts that Latin America is making to satisfy the demand in training young Latin American minds for the developmental biology of the future. I focus on a particular course that has been linked to the origins of the Latin America Society of Developmental Biology (LASDB). I describe the motivations to start organizing this course twenty years ago, its history and setbacks. We tracked back the current situation of former students to find out that more than 90% are still doing developmental biology all across the globe. I describe the state of affairs of the Course in its current location in the CIMARQ campus of the Universidad Andres Bello (UNAB), in a place called Quintay on the Chilean coast and I ask about its future.

The cytochrome P450 superfamily is a large enzymatic protein family that is widely distributed along diverse kingdoms. In plants, cytochrome P450 monooxygenases (CYPs) participate in a vast array of pathways leading to the synthesis and modification of multiple metabolites with variable and important functions during different stages of plant development. This includes the biosynthesis and degradation of a great assortment of compounds implicated in a variety of physiological responses, such as signaling and defense, organ patterning and the biosynthesis of structural polymers, among others. In this review, we summarize the characteristics of the different families of plant CYPs, focusing on the most recent advances in elucidating the roles of CYPs in plant growth and development and more specifically, during plant gametogenesis, fertilization and embryogenesis.

The axolotl (Ambystoma mexicanum) has been a widely studied organism due to its capacity to regenerate most of its cells, tissues and whole-body parts. Since its genome was sequenced, several molecular tools have been developed to study the mechanisms behind this outstanding and extraordinary ability. The complexity of its genome due to its sheer size and the disproportionate expansion of a large number of repetitive elements, may be a key factor at play during tissue remodeling and regeneration mechanisms. Transcriptomic analysis has provided information to identify candidate genes networks and pathways that might define successful or failed tissue regeneration. Nevertheless, the epigenetic machinery that may participate in this phenomenon has largely not been studied. In this review, we outline a broad overview of both genetic and epigenetic molecular processes related to regeneration in axolotl, from the macroscopic to the molecular level. We also explore the epigenetic mechanisms behind regenerative pathways, and its potential importance in future regeneration research. Altogether, understanding the genomics and global regulation in axolotl will be key for elucidating the special biology of this organism and the fantastic phenomenon that is regeneration.

The history of science in Argentina is based on the enormous contribution that the great immigration of the 19th and 20th centuries produced in the country. The scientific and philosophical ideas and the role played especially by Italian scientists who arrived in the country produced a great impact on the different disciplines including Development Biology in emerging universities. The University of Tucumán pioneered the study of experimental biology, making important contributions to reproductive biology and to the early development of amphibians. The contribution of the Italian embryologist Armando Pisanó and the Argentinian Francisco D. Barbieri expanded the field to other universities and research centers located in Córdoba, La Plata, Bahía Blanca and Rosario. Given its strategic position, laboratories located in the city of Buenos Aires reached technological advances faster than others. Indeed, these laboratories saw the evolution from experimental biology to developmental genetics, renewing interest in this area. Currently, Developmental Biology brings together young researchers eager to consolidate regional and global collaboration networks that seek to help solve specific problems such as fertility, epigenetics, stem cells and tissue engineering.