Related Experiment Video
Updated: Aug 9, 2026
09:16
Analyzing Craniofacial Morphogenesis in Zebrafish Using 4D Confocal Microscopy
Published on: January 30, 2014
Hox genes specify vertebral types in the presomitic mesoderm
Marta Carapuço1, Ana Nóvoa, Nicoletta Bobola
1Instituto Gulbenkian de Ciencia, 2780-156 Oeiras, Portugal.
Genes & Development
|September 17, 2005
Summary
Hox gene expression in the presomitic mesoderm, not somites, is crucial for axial skeleton patterning. This study reveals distinct Hox gene roles in development, impacting vertebral and rib formation.
Area of Science:
- Developmental Biology
- Genetics
- Skeletal Biology
Background:
- Hox genes are critical for establishing anterior-posterior body axis patterning.
- Understanding the precise roles of Hox genes in different embryonic tissues is essential for deciphering developmental processes.
Purpose of the Study:
- To investigate the distinct roles of Hox gene expression in the presomitic mesoderm versus somites during axial skeleton development.
- To determine how Hox group 10 and 11 genes influence vertebral and rib formation.
Main Methods:
- Analysis of Hoxa10 and Hoxa11 expression in specific embryonic tissues.
- Investigating the effects of gene inactivation, specifically Gbx2, on axial skeleton development.
- Phenotypic analysis of vertebral and rib formation.
Main Results:
- Hoxa10 expression in the presomitic mesoderm, but not somites, leads to vertebrae lacking ribs.
- Hoxa11 expression in the presomitic mesoderm is required for vertebral sacralization, while expression in somites is needed for caudal differentiation.
- Inactivation of Gbx2, a presomitic mesoderm gene, results in Hox-like axial skeleton phenotypes without altering Hox gene expression.
Conclusions:
- Hox gene patterning activity differs significantly between the presomitic mesoderm and somites.
- The presomitic mesoderm plays a prominent role in Hox gene-mediated axial skeleton patterning.
- Gbx2 acts independently of Hox gene expression to influence axial skeleton development, suggesting parallel regulatory pathways.
More Related Videos
Related Concept Videos
01:33Pleiotropy
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
01:56Gastrulation
Gastrulation establishes the three primary tissues of an embryo: the ectoderm, mesoderm, and endoderm. This developmental process relies on a series of intricate cellular movements, which in humans transforms a flat, “bilaminar disc” composed of two cell sheets into a three-tiered structure. In the resulting embryo, the endoderm serves as the bottom layer, and stacked directly above it is the intermediate mesoderm, and then the uppermost ectoderm. Respectively, these tissue strata will form...
01:30Neurulation
Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the anterior...
01:51Determination
During embryogenesis, cells become progressively committed to different fates through a two-step process: specification followed by determination. Specification is demonstrated by removing a segment of an early embryo, “neutrally” culturing the tissue in vitro—for example, in a petri dish with simple medium—and then observing the derivatives. If the cultured region gives rise to cell types that it would normally generate in the embryo, this means that it is specified. In contrast, determination...
02:33Hedgehog Signaling Pathway
The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
01:15Development of the Sexual Organs in the Embryo and Fetus
Development of the reproductive organs in an embryo starts from a bipotential state. This means the early embryo can develop either male or female reproductive organs. The formation of these organs begins with the growth of gonadal ridges that arise from the intermediate mesoderm during the fifth week of development.
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...