Developmental Biology

Genes help guide embryonic development, the process that turns a single-celled embryo into a multicellular organism. Developmental biology asks how information in DNA directs this change. Developmental geneticists study how specific genes control embryonic processes and help build a complete organism.

This topic also covers the major questions in the field and the methods used to answer them. Researchers use prominent experimental approaches to link genes with development. The video also shows...

Morpholino microinjection in zebrafish is a way to silence genes during development. Morpholinos are short oligonucleotides that bind to complementary mRNAs and block gene expression. Their unique chemistry makes them easy to produce and store, which can make them more cost effective than other gene silencing methods.

Careful experimental design is important when using morpholinos. The method depends on choosing the right target and planning the injection approach before testing the effects on...

Transgenesis is a genetic engineering method used in developmental biology to change gene expression. Scientists use it to study how genes affect development by altering gene function in model organisms.

One common strategy is to replace a gene with a nonfunctional copy. Another is to add a visual tag to a gene so the fusion protein can be tracked during development. These approaches help researchers follow gene activity and see where proteins go in an animal.

The process also includes the...

Embryonic development depends on molecular signals that guide cells as they change and move. These signals help control cell differentiation, which is the process that makes cells into specific types, and cell migration, which is the movement of cells to new locations. Together, these events shape the tissues and structures that form during development.

Molecular developmental biology uses molecular tools to study these physical and chemical processes in detail. The field also has a history...

Explant culture lets living embryonic tissue continue developing outside the body. Researchers remove cells or tissues from an embryo and grow them ex vivo, which means outside the organism. This setup makes it possible to watch and control developing tissues in ways that are not possible in vivo, or inside the organism.

Once explant cultures are established, they are often used to study how genes and signaling molecules guide organ development. The method is especially useful for...

Whole-mount in situ hybridization is a method for showing where RNA is expressed in embryos. It helps researchers see spatial and temporal patterns of gene expression across an entire embryo or structure.

The method uses synthetically made RNA probes that bind to matching target transcripts. These RNA hybrids are then detected with immunohistochemistry or fluorescence. The signal shows where the gene of interest is active.

Whole-mount staining differs from traditional in situ hybridization,...

Stem cells are cells that can develop into many cell types, and they play a major role in modern biology. Researchers study how these cells work because they may help explain normal development and disease. They also study how stem cells could be used to treat human illness.

The field has grown through a series of landmark studies. Early evidence for hematopoietic stem cells appeared in the 1960s. More recent work led to induced pluripotent stem cells, or iPS cells, which are adult cells that...

Embryonic stem (ES) cell culture depends on keeping cells undifferentiated. In this state, they can self-renew and remain pluripotent, which means they can still form many different cell types.

This page explains the basic principles of ES cell culture and shows a general method for growing and passaging the cells. Passaging means moving cells into a new dish so they can keep growing under the right conditions.

The page also highlights the hanging drop method for differentiation. In this...

Induced pluripotent stem cells, or iPSCs, are made by reprogramming mature somatic cells back into an undifferentiated state. These cells behave like embryonic stem cells in culture. Under the right growth conditions, they can then be directed to become different cell types.

This makes iPSCs an important tool for regenerative medicine. They may provide a potentially unlimited source of human cells for research and future therapies. However, scientists still need more work on how iPSCs are made...

Organogenesis is the stage of embryonic development when organs begin to form from the three germ layers. These early tissue layers give rise to different organs as the embryo develops. Scientists study this process to learn how organs are built and how development is controlled.

Developmental biologists focus on the genetic programs, cell-cell interactions, and mechanical forces that guide organ formation. They also ask how these signals work together during normal development. Understanding...

Fate mapping traces how embryonic cells divide, differentiate, and migrate during development. It helps scientists see which cells give rise to specific tissues and structures. The method links early cell position to later cell fate.

In classic fate mapping experiments, cells in different areas of an embryo are labeled with a chemical dye. Researchers then track the labeled cells over time. This shows which tissues or structures those cells form as the embryo develops.

New technology has made...

Embryo tissue transplantation helps scientists study how cells become specific tissues during development. Developmental biologists focus on the molecular signals and cell interactions that tell a group of cells what to become. This approach is useful for tracing how those early instructions shape growing embryos.

The method uses tissue from a donor embryo and places it into a host embryo. Researchers first excise the donor tissue, then graft it into the host. By watching how the transplanted...

Cellular aging and tissue repair help explain how the body keeps its tissues working over time. Aging is the gradual loss of cell function. Regeneration is the repair of damaged tissue, and it is often mediated by preexisting adult, or somatic, stem cells.

Scientists study these processes to understand the biological mechanisms behind them. This research may help explain how somatic stem cells could be used to treat degenerative diseases. It may also lead to therapies that slow some effects of...

Measuring aging in flies and worms helps scientists study lifespan. Lifespan is the time between birth and death. After animals reach adulthood, many stop growing and begin aging, or senescence, until they die.

Scientists use different growth conditions to learn which biological and environmental factors affect lifespan. Flies and worms are useful for these experiments because they have short generation times and are easy to culture. The transcript also notes that lifespan can change with...

Adult stem cells, also called somatic stem cells, help maintain tissues and support repair after injury. These cells can self-renew, which means they make more stem cells. They also have a limited range of cell fates compared with embryonic stem cells.

Somatic stem cells are important in homeostasis, the process that keeps tissues working normally. They also play a role in tissue regeneration. Scientists study and manipulate these cells to better understand how new regenerative therapies might...