Journal of Developmental Biology

817 KiB

Open AccessReview

by Stéphane Zaffran, Nicolas El Robrini and Nicolas Bertrand

J. Dev. Biol. 2014, 2(1), 50-71; https://doi.org/10.3390/jdb2010050 - 21 Mar 2014

Cited by 18 | Viewed by 13129

Retinoic acid (RA), a derivative of vitamin A, is involved in signal transduction during vertebrate organogenesis. Retinoids through binding to nuclear receptors called RA receptors (RARs) and retinoid X receptors (RXRs) regulate various processes during cardiogenesis. Deregulated retinoid signaling thus has later consequences leading to cardiac malformations. In this review, we will summarize and discuss our current knowledge on the role of RA signaling during heart development, especially during patterning of the heart fields. We have also integrated recent experiments essential for our understanding of the role of RA signaling during epicardial development and myocardial growth. Full article

(This article belongs to the Special Issue Retinoids in Development)

► Show Figures

Figure 1

799 KiB

Open AccessReview

Checking the Pulse of Vitamin A Metabolism and Signaling during Mammalian Spermatogenesis

by Travis Kent and Michael D. Griswold

J. Dev. Biol. 2014, 2(1), 34-49; https://doi.org/10.3390/jdb2010034 - 21 Mar 2014

Cited by 5 | Viewed by 12898

Abstract

Vitamin A has been shown to be essential for a multitude of biological processes vital for mammalian development and homeostasis. Its active metabolite, retinoic acid (RA), is important for establishing and maintaining proper germ cell development. During spermatogenesis, the germ cells orient themselves in very distinct patterns, which have been organized into stages. There is evidence to show that, in the mouse, RA is needed for many steps during germ cell development. Interestingly, RA has been implicated as playing a role within the same two Stages: VII and VIII, where meiosis is initiated and spermiation occurs. The goal of this review is to outline this evidence, exploring the relevant players in retinoid metabolism, storage, transport, and signaling. Finally, this review will provide a potential model for how RA activity is organized across the murine stages of the spermatogenic cycle. Full article

(This article belongs to the Special Issue Retinoids in Development)

► Show Figures

Figure 1

711 KiB

Open AccessReview

Signaling by Retinoic Acid in Embryonic and Adult Hematopoiesis

by Elena Cano, Laura Ariza, Ramón Muñoz-Chápuli and Rita Carmona

J. Dev. Biol. 2014, 2(1), 18-33; https://doi.org/10.3390/jdb2010018 - 17 Mar 2014

Cited by 3 | Viewed by 13087

Abstract

Embryonic and adult hematopoiesis are both finely regulated by a number of signaling mechanisms. In the mammalian embryo, short-term and long-term hematopoietic stem cells (HSC) arise from a subset of endothelial cells which constitute the hemogenic endothelium. These HSC expand and give rise to all the lineages of blood cells in the fetal liver, first, and in the bone marrow from the end of the gestation and throughout the adult life. The retinoic acid (RA) signaling system, acting through the family of nuclear retinoic acid receptors (RARs and RXRs), is involved in multiple steps of the hematopoietic development, and also in the regulation of the differentiation of some myeloid lineages in adults. In humans, the importance of this RA-mediated control is dramatically illustrated by the pathogeny of acute promyelocytic leukemia, a disease produced by a chromosomal rearrangement fusing the RARa gene with other genes. The aberrant fusion protein is able to bind to RARα target gene promoters to actively suppress gene transcription. Lack of function of RARα leads to a failure in the differentiation of promyelocytic progenitors. In this review we have collected the available information about all the phases of the hematopoietic process in which RA signaling is involved, being essential for steps such as the emergence of HSC from the hemogenic endothelium, or modulating processes such as the adult granulopoiesis. A better knowledge of the RA-mediated signaling mechanisms can contribute to the knowledge of the origin of many pathologies of the hematopoietic system and can provide new clinical avenues for their treatment. Full article

(This article belongs to the Special Issue Retinoids in Development)

► Show Figures

Figure 1

1016 KiB

Open AccessReview

The Epicardium and the Development of the Atrioventricular Junction in the Murine Heart

by Marie M. Lockhart, Aimee L. Phelps, Maurice J. B. Van den Hoff and Andy Wessels

J. Dev. Biol. 2014, 2(1), 1-17; https://doi.org/10.3390/jdb2010001 - 4 Mar 2014

Cited by 32 | Viewed by 9806

Abstract

Insight into the role of the epicardium in cardiac development and regeneration has significantly improved over the past ten years. This is mainly due to the increasing availability of new mouse models for the study of the epicardial lineage. Here we focus on the growing understanding of the significance of the epicardium and epicardially-derived cells in the formation of the atrioventricular (AV) junction. First, through the process of epicardial epithelial-to-mesenchymal transformation (epiEMT), the subepicardial AV mesenchyme is formed. Subsequently, the AV-epicardium and epicardially-derived cells (EPDCs) form the annulus fibrosus, a structure important for the electrical separation of atrial and ventricular myocardium. Finally, the AV-EPDCs preferentially migrate into the parietal AV valve leaflets, largely replacing the endocardially-derived cell population. In this review, we provide an overview of what is currently known about the regulation of the events involved in this process. Full article

(This article belongs to the Special Issue Epicardial Development and Cardiovascular Disease)

► Show Figures

Figure 1

Journal Menu

Journal Browser

J. Dev. Biol., Volume 2, Issue 1 (March 2014) – 4 articles , Pages 1-71

Further Information

Guidelines

MDPI Initiatives

Follow MDPI