Violations of the regulation of genes by transcription factors: polysyndactyly

Fundamental mechanisms during development

  • Regulation of genes by transcription factors.
  • Intercellular signaling through direct contact and morphogeny.
  • Induction of shape and cell polarity.
  • Moving cells.
  • Programmable cell death.

Regulation of genes by transcription factors

Transcription factors control the development by altering the expression of genes, including other transcription factors. Group functioning together of (more…)

The human embryogenesis. Theodosiya and stem cells

In the course of development, cells divide (reproduce), acquire new functions or structure (differencemode), move within the embryo (migrate) and undergo programmed death (often via apoptosis). These four major cellular process that act in different combinations and in different ways lead to growth and morphogenesis (literally “creation of form”), creating the (more…)

Genetics of development: the impact of genes and environment

Development is determined by genes that interact with cellular and environmental surroundings. Involved gene products include transcription regulators, factors of diffusion of interacting with cells and guides them along specific development pathways to receptors for such factors, structural proteins, intracellular signaling molecules and much more. Not surprisingly, the most numerous developmental (more…)

Causes of congenital malformations. Etiology

Malformations have many causes. Chromosomal abnormalities account for approximately 25% of all causes, of which the most common autosomal trisomy of chromosomes 21, 18 and 13.

Another 20% are caused by monogenic mutations. Some defects are inherited as autosomal dominant traits, such as achondroplasia or waardenburg syndrome. Nevertheless, the majority of heterozygotes (more…)

Biology of development. Evolution

Developmental biology deals with the only thing uniting all the question: how a single cell can develop into a Mature organism? In humans, this conversion occurs whenever a single fertilized egg develops into a person with more than 1013-1014 cells, several hundred distinct cell types and dozens of fabrics. This process (more…)

Pleiotropy. Pleiotropic syndromes

In studies of birth defects clinical dysmorphology constantly confronted with the phenomenon of pleiotropy. Congenital defects are pleiotropy, when the only primary pathogen causes abnormalities in more than one organ system in different parts of the embryo or in multiple structures that arise at different times of fetal life. Agent responsible (more…)