I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Principles of Neural Science

Blood vessels and lymphatic vessels form extensive networks that are essential for the transport of fluids, gases, macromolecules and cells within the large and complex bodies of vertebrates. Both of these vascular structures are lined with endothelial cells that integrate functionally into different organs, acquire tissue-specific specialization and retain plasticity; thereby, they permit growth during tissue repair or in disease settings. The angiogenic growth of blood vessels and lymphatic vessels coordinates several biological processes such as cell proliferation, guided migration, differentiation and cell-cell communication.

Molecular regulation of angiogenesis and lymphangiogenesis.

https://www.cell.com/cell/pdf/S0092-8674(15)00377-3.pdf

Disruptions of Topological Chromatin Domains Cause Pathogenic Rewiring of Gene-Enhancer Interactions

Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process invol...

Satellite Cells and the Muscle Stem Cell Niche

Both acquired and inherited disorders of muscle are common; thus, greater understanding of muscle growth and maintenance is important for future therapies. Myostatin down-regulates muscle growth. These investigators describe a mutation in the gene for myostatin in a child with muscle hypertrophy and unusual strength.

Myostatin Mutation Associated with Gross Muscle Hypertrophy in a Child

Development of somite cells is orchestrated by two regulatory processes. Differentiation of cells from the various somitic compartments into different anlagen and tissues is regulated by extrinsic signals from neighboring structures such as the notochord, neural tube, and surface ectoderm. Morphogenesis of these anlagen to form specific structures according to the segmental identity of each somite is specified by segment-specific positional information, based on the Hox-code. It has been shown that following experimental rotation of presomitic mesoderm or newly formed somites, paraxial mesodermal cells adapt to the altered signaling environment and differentiate according to their new orientation. In contrast, presomitic mesoderm or newly formed somites transplanted to different segmental levels keep their primordial segmental identity and form ectopic structures according to their original position. To determine whether all cells of a segment, including the dorsal and ventral compartment, share the same segmental identity, presomitic mesoderm or newly formed somites were rotated and transplanted from thoracic to cervical level. These experiments show that cells from all compartments of a segment are able to interpret extrinsic local signals correctly, but form structures according to their original positional information and maintain their original Hox expression in the new environment.

Cells of all somitic compartments are determined with respect to segmental identity.

Background
The myotome is the primitive skeletal muscle that forms within the embryonic metameric body wall. It can be subdivided into an epaxial and hypaxial domain. It has been shown that the formation of the epaxial myotome requires the dorsomedial lip of the dermomyotome (DML). Although the ventrolateral lip (VLL) of the dermomyotome is believed to be required for the formation of the hypaxial myotome, experimentally evidence for this statement still needs to be provided. Provision of such data would enable the resolution of a debate regarding the formation of the hypaxial dermomyotome. Two mechanisms have been proposed for this tissue. The first proposes that the intermediate dermomyotome undergoes cellular expansion thereby pushing the ventral lateral lip in a lateral direction (translocation). In contrast, the alternative view holds that the ventral lateral lip grows laterally.

/pdf/the-dermomyotome-ventrolateral-lip-is-essential-for-the-2bxjsmj24p.pdf

The dermomyotome ventrolateral lip is essential for the hypaxial myotome formation

Notch and Delta signaling regulates cell-fate decisions in a variety of tissues in diverse organisms through cell-to-cell interactions. In this study we isolated a 696 bp fragment of chick Delta-like 4 (Dll4) cDNA and analyzed its expression pattern during chick development by in situ hybridization. We report a detailed description of cDll4 expression from HH-stage 8-30. Expression is seen in extraembryonic tissues and in the dorsal aorta throughout development but is absent from venules. Dll4 is expressed in the embryonic blood vessels, heart, somites, neural tube, limb, pharyngeal arches, esophagus, and in the developing eye. In accordance with the report from mice, cDll4 is a marker of the arterial type of endothelial cells. These analyses show that Dll4 is expressed in a wide range of tissues and organs suggesting its role in vascular development during chick embryogenesis.

Expression pattern of Dll4 during chick embryogenesis.

Signalling cascades first described in Drosophila have been found to regulate patterning and outgrowth in a number of structures in higher vertebrates. We sought to determine whether the evolutionarily conserved genes were important during the development of the tongue. In situ hybridisation was used to determine the temporo-spatial expression of a panel of conserved genes. Histological examination and incorporation of BrdU were used to determine the mechanism by which the tongue develops. We show that evolutionarily conserved genes were expressed in distinct dynamic patterns during tongue development. Sonic Hedgehog (Shh) and Patched (Ptc) were found only in the dorsal tongue epithelium. Shh expression was only observed in the suprabasal layers, whereas Ptc was observed in both basal and suprabasal layers. Cell division in the epithelium was concentrated in regions devoid of Shh. Expression of bone morphogenetic protein-7 (BMP) was identical to that of Shh. Shh and Ptc expression were never detected in the mesenchyme. Ectopic expression of Noggin (a potent antagonist of the BMPs) caused severe abnormalities in tongue morphology, including swelling of the mesenchymal component and a thickening of the epithelial layer. Data from this study suggests that the epithelium and mesenchyme express quite different genes during development. However BMP activity acts to inhibit growth in both tissues.

Molecular and cellular analysis of embryonic avian tongue development.

Somites compartmentalize into a dorsal epithelial dermomyotome and a ventral mesenchymal sclerotome. While sclerotomes give rise to vertebrae and intervertebral discs, dermomyotomes contribute to skeletal muscle and epaxial dermis. Bone morphogenetic protein (BMP)-signals from the lateral mesoderm induce the lateral portion of the dermomyotome to form chondrogenic precursor cells, forming the cartilage of the scapula blade. The fact that BMPs are expressed in the roof plate of the neural tube where they induce cartilage formation led to the question why cells migrating from the medial part of the dermomyotome do not undergo chondrogenic differentiation and do not contribute to the dorsal part of the vertebrae. In the present study, we traced dermomyotomal derivatives by using the quail–chick marker technique. Our study reveals a temporal sequence in the formation of the vertebral cartilage and the midline dermis. The dorsal mesenchyme overlying the roof plate of the neural tube is formed prior to the de-epithelialization of the dermomyotome. Dermomyotomal cells start to migrate medially into the sub-ectodermal space to form the midline dermis after chondrogenesis of the dorsal mesenchyme has occurred. This time delay between chondrogenesis of the dorsal vertebra and dermal formation allows an undisturbed development of these two tissue components within a narrow region of the embryo.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7580.2012.01518.x

Ruijin Huang

Papers

Cells of all somitic compartments are determined with respect to segmental identity.

The dermomyotome ventrolateral lip is essential for the hypaxial myotome formation

Expression pattern of Dll4 during chick embryogenesis.

Molecular and cellular analysis of embryonic avian tongue development.

Temporal sequence in the formation of midline dermis and dorsal vertebral elements in avian embryos.