What is Somite formation?
Somite formation begins as paraxial mesoderm cells become organized into whorls of cells called somitomeres. The somitomeres become compacted and bound together by an epithelium, and eventually separate from the presomitic paraxial mesoderm to form individual somites.
What is a Somite pair?
Anatomical terminology. The somites (outdated term: primitive segments) are a set of bilaterally paired blocks of paraxial mesoderm that form in the embryonic stage of somitogenesis, along the head-to-tail axis in segmented animals.
What does Somite turn into?
Somites are precursor populations of cells that give rise to important structures associated with the vertebrate body plan and will eventually differentiate into dermis, skeletal muscle, cartilage, tendons, and vertebrae.
What cellular movements are involved in fish gastrulation?
The first cell movement of fish gastrulation is the epiboly of the blastoderm cells over the yolk. In the initial phase, the deep blastoderm cells move outwardly to intercalate with the more superficial cells (Warga and Kimmel 1990).
What is meant by the term somite quizlet?
Somites. Somites are transient structures that do not exist in the adult. They disappear as organogenesis proceeds.
Is zebrafish a telolecithal?
The following brief description of zebrafish development is derived predominantly from Kimmel et al. (1995). The teleost egg is telolecithal; i.e., a mound of cytoplasm (the blastodisc) sits on the large mass of yolk and undergoes incomplete (meroblastic) cleavage.
Which part of the somite gives axial and back muscles of the body?
The dorsal epithelial structure of the somite is maintained in the dermomyotome which eventually gives rise to the epaxial muscles of the vertebrae and back (medial myotome), the hypaxial muscles of the body wall and limbs (lateral myotome), and the dermis of the skin of the trunk (dermatome).
What are somites simple definition?
somite, in embryology, one of a longitudinal series of blocklike segments into which the mesoderm, the middle layer of tissue, on either side of the embryonic spine becomes divided. Collectively, the somites constitute the vertebral plate.
Why study somite development in the zebrafish?
A full understanding of somite development requires knowledge of the molecular genetic pathways for cell determination as well as the cellular behaviors that underlie segmentation, somite epithelialization, and somite patterning. The zebrafish has long been recognized as an ideal organism for cellular and histological studies of somite patterning.
What is the role of the segmentation clock in zebrafish?
Role of the segmentation clock The segmentation clock in zebrafish consists of intracellular genetic oscillators thought to arise from a delayed negative feedback loop involving the Hes/Her family of bHLH transcription factors [8].
What are somites in anatomy?
The body axis of vertebrates is subdivided into repetitive compartments called somites, which give rise primarily to the segmented architecture of the musculoskeletal system in the adult body.
How are oscillations in segmentation clock genes synchronized across cells?
Oscillations in segmentation clock genes are locally synchronized across groups of cells primarily through Delta-Notch (D/N) coupling and traverse anteriorward as a kinematic wave through the unsegmented tissue (presomitic mesoderm, PSM) . The arrest of the wave in the anterior occurs at a position that prefigures prospective somite boundaries.