GO:0060681 branch elongation involved in ureteric bud branching: Developmental Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0060681 describes the growth of a branch of the ureteric bud along its axis, a key step in kidney branching morphogenesis.
• Ureteric bud branching generates the collecting duct system of the kidney, and its disruption causes renal dysplasia and vesico-ureteric reflux.
• Branch elongation is spatiotemporally regulated by morphogenetic molecules such as growth factors and extracellular matrix components.
• The cell adhesion molecule L1 is developmentally regulated in renal epithelium and is involved in kidney branching morphogenesis.
• Transgenic GFP expression in the ureteric bud provides a powerful tool to visualize and analyze ureteric bud morphogenesis.
• Architectural patterns of branching morphogenesis in the kidney reveal that elongation and branching are distinct but coordinated processes.
Description
GO:0060681, branch elongation involved in ureteric bud branching, is a biological process defined as the growth of a branch of the ureteric bud along its axis. The ureteric bud is an epithelial outgrowth of the Wolffian duct that invades the metanephric mesenchyme and undergoes iterative branching to form the collecting duct system of the kidney. Branch elongation is a fundamental component of this branching program, ensuring that each newly formed branch extends appropriately to establish the complex architecture of the renal collecting system. Understanding this process is critical because defects in ureteric bud branching underlie congenital anomalies of the kidney and urinary tract, including renal dysplasia and vesico-ureteric reflux. Researchers study GO:0060681 to dissect the molecular and cellular mechanisms that control epithelial tube growth and to identify genes whose mutations contribute to human renal disease. The process is experimentally accessible through in vitro branching assays of the isolated ureteric bud and through transgenic mouse models that label the ureteric bud with green fluorescent protein.
branch elongation involved in ureteric bud branching At A Glance
| GO ID | GO:0060681 |
|---|---|
| GO term | branch elongation involved in ureteric bud branching |
| Ontology | biological_process |
| Synonym | none |
| Definition | The growth of a branch of the ureteric bud along its axis. |
| Major function | Elongation of ureteric bud branches during kidney development |
| Parent process | ureteric bud branching morphogenesis |
| Related anatomy | Ureteric bud, collecting duct system |
| Key experimental models | In vitro isolated ureteric bud branching assay, GFP-transgenic mice |
What Is GO:0060681?
In our own words, GO:0060681 refers to the directed growth or extension of a branch of the ureteric bud along its own axis. It is a subprocess of ureteric bud branching morphogenesis, distinct from branch initiation or bifurcation, and focuses specifically on the elongation phase that lengthens an existing branch. This process is driven by coordinated cell proliferation, cell rearrangement, and extracellular matrix remodeling within the ureteric bud epithelium and its surrounding mesenchyme.
Why Is branch elongation involved in ureteric bud branching Important in Cell Biology?
GO:0060681 is important because ureteric bud branch elongation is essential for establishing the correct number and spatial arrangement of collecting ducts in the kidney. Disruption of this process leads to renal dysplasia and congenital anomalies of the kidney and urinary tract, including vesico-ureteric reflux. Studying branch elongation provides insight into fundamental mechanisms of epithelial tube growth and branching that are conserved across organs and relevant to tissue engineering and regenerative medicine.
• Branch elongation determines the final architecture of the renal collecting duct system.
• Defects in ureteric bud branching cause renal dysplasia and vesico-ureteric reflux.
• The process is regulated by spatiotemporal expression of morphogenetic molecules.
• Cell adhesion molecules such as L1 are involved in kidney branching morphogenesis.
• GFP-transgenic mice allow real-time visualization of ureteric bud elongation.
• In vitro branching assays of the isolated ureteric bud enable mechanistic studies.
• Understanding branch elongation informs tissue engineering of kidney structures.
• Conserved mechanisms of branching morphogenesis are relevant to other organs.
• Genetic mutations affecting branching can be modeled in mice and cell culture.
• The process is a target for studying congenital kidney disease pathogenesis.
What Happens During branch elongation involved in ureteric bud branching?
Initiation and outgrowth of the ureteric bud
In simple terms: The ureteric bud first grows out from the Wolffian duct and invades the kidney mesenchyme.
The ureteric bud emerges as an epithelial outgrowth from the Wolffian duct and invades the metanephric mesenchyme, initiating a program of branching morphogenesis. This initial outgrowth sets the stage for subsequent branch elongation events that will generate the collecting duct system.
Directed elongation of branches along their axis
In simple terms: Each branch extends lengthwise to form a longer tube.
Once a branch is specified, it elongates along its axis through coordinated cell proliferation and rearrangement within the ureteric bud epithelium. This elongation phase is distinct from branch initiation and is regulated by spatiotemporal cues from the surrounding mesenchyme.
Role of cell adhesion molecules in elongation
In simple terms: Adhesion molecules help cells stick together and move properly during branch growth.
The cell adhesion molecule L1 is developmentally regulated in the renal epithelium and is involved in kidney branching morphogenesis, suggesting that adhesion dynamics are critical for branch elongation. L1 expression patterns correlate with regions of active branching and elongation in the developing kidney.
Visualization of branch elongation using GFP-transgenic models
In simple terms: Scientists can watch the ureteric bud grow in living mice using a fluorescent tag.
Transgenic mice expressing green fluorescent protein in the ureteric bud provide a new tool for analyzing ureteric bud morphogenesis, including branch elongation. This approach allows real-time imaging of the elongating branches and their interactions with surrounding tissues.
In vitro modeling of ureteric bud branching and elongation
In simple terms: Isolated ureteric buds can be grown in dishes to study branching step by step.
In vitro branching of the isolated ureteric bud has been used to define a model of branching through budding, revealing spatiotemporal regulation of morphogenetic molecules during elongation. Such assays allow controlled manipulation of signaling pathways to dissect their roles in branch elongation.
Key Genes Involved in GO:0060681 branch elongation involved in ureteric bud branching
The following genes and proteins have been implicated in ureteric bud branching and elongation based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| L1CAM | Cell adhesion molecule involved in kidney branching morphogenesis | Studied in L1 mutant mice and renal epithelial cells |
| GDNF | Glial cell line-derived neurotrophic factor, a key inducer of ureteric bud outgrowth | Target of branching morphogenesis studies |
| RET | Receptor tyrosine kinase for GDNF signaling in ureteric bud | Mutated in renal agenesis and dysplasia |
| GFRA1 | Co-receptor for GDNF | Involved in ureteric bud induction |
| WNT11 | Secreted signaling molecule in ureteric bud branching | Studied in branching morphogenesis |
| WNT9B | Secreted signaling molecule in ureteric bud induction | Studied in kidney development |
| FGF10 | Fibroblast growth factor, mesenchymal signal to ureteric bud | Target of branching studies |
| BMP4 | Bone morphogenetic protein, regulates branching angle and elongation | Studied in ureteric bud explants |
| SHH | Sonic hedgehog, involved in ureteric bud branching | Analyzed in transgenic models |
| PAX2 | Transcription factor essential for ureteric bud lineage | Mutated in renal coloboma syndrome |
| PAX8 | Transcription factor in kidney development | Studied in congenital kidney disease |
| HNF1B | Transcription factor regulating ureteric bud branching | Mutated in renal cysts and diabetes syndrome |
| EYA1 | Transcription coactivator in kidney development | Mutated in branchio-oto-renal syndrome |
| SIX1 | Transcription factor interacting with EYA1 | Studied in renal anomalies |
| SALL1 | Transcription factor in kidney development | Mutated in Townes-Brocks syndrome |
| WT1 | Transcription factor in metanephric mesenchyme | Studied in Wilms tumor and renal development |
| GATA3 | Transcription factor in ureteric bud differentiation | Mutated in renal dysplasia |
How Is branch elongation involved in ureteric bud branching Regulated?
Branch elongation involved in ureteric bud branching is regulated by a complex network of secreted morphogens, transcription factors, and cell adhesion molecules. Spatiotemporal regulation of morphogenetic molecules during in vitro branching of the isolated ureteric bud suggests that growth factors such as FGFs and BMPs modulate the rate and direction of elongation. The cell adhesion molecule L1 is developmentally regulated in the renal epithelium and contributes to branching morphogenesis, indicating that adhesion dynamics are part of the regulatory control. Transgenic GFP expression in the ureteric bud has enabled analysis of how these regulatory factors affect branch elongation in vivo.
branch elongation involved in ureteric bud branching and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| RET | Renal agenesis, Hirschsprung disease | Ret knockout mouse, ureteric bud cell culture |
| PAX2 | Renal coloboma syndrome | Pax2 mutant mouse, in vitro branching assay |
| HNF1B | Renal cysts and diabetes syndrome | Hnf1b knockout mouse, ureteric bud organoids |
| EYA1 | Branchio-oto-renal syndrome | Eya1 mutant mouse, GFP-transgenic ureteric bud |
| L1CAM | Kidney branching morphogenesis defects | L1 mutant mouse, renal epithelial cell assays |
Congenital anomalies of the kidney and urinary tract (CAKUT)
Disruption of ureteric bud branching and elongation is a major cause of congenital anomalies of the kidney and urinary tract, including renal dysplasia and vesico-ureteric reflux. Mutations in genes such as RET, PAX2, HNF1B, and EYA1 have been linked to these conditions, highlighting the clinical importance of understanding branch elongation mechanisms.
Renal dysplasia
Renal dysplasia often results from abnormal ureteric bud branching, leading to disorganized kidney tissue and impaired function. Studies of embryology and genetics of primary vesico-ureteric reflux and associated renal dysplasia provide insights into how defects in branch elongation contribute to disease.
Vesico-ureteric reflux
Vesico-ureteric reflux is associated with abnormal development of the ureteric bud and its branches, which can result from defective elongation. Understanding the genetic basis of ureteric bud branching helps identify risk factors and potential therapeutic targets.
From branch elongation involved in ureteric bud branching-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate ureteric bud branch elongation? | Knockout mouse or in vitro isolated ureteric bud assay |
| Does a specific point mutation in gene X affect branching? | Point-mutation knock-in mouse |
| How does tagged protein X localize during elongation? | Tagged knock-in (e.g., GFP) in ureteric bud |
| Does overexpression of gene X enhance or inhibit elongation? | Overexpression transgenic mouse or lentiviral transduction |
| What is the role of cell adhesion molecule L1 in elongation? | L1 knockout and rescue experiments |
| Can human disease mutations be modeled in kidney organoids? | CRISPR-edited human iPSC-derived kidney organoids |
How to Study the branch elongation involved in ureteric bud branching Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro branching assay | Branch number, length, and elongation rate | Testing effects of growth factors on ureteric bud |
| GFP-transgenic imaging | Real-time branch elongation dynamics | Visualizing ureteric bud morphogenesis |
| Immunohistochemistry | Protein localization and expression | Detecting L1 and other markers in renal epithelium |
| In situ hybridization | mRNA expression patterns | Mapping morphogenetic molecule transcripts |
| Genetic lineage tracing | Cell fate and contribution to branches | Tracing ureteric bud descendants |
| Organoid culture | Three-dimensional branching morphogenesis | Modeling human kidney development |
| CRISPR knockout | Gene function in branching | Testing candidate genes in ureteric bud cells |
| RNA-seq | Transcriptional profiles during elongation | Identifying differentially expressed genes |
In vitro ureteric bud branching assay
The isolated ureteric bud can be cultured in vitro to study branching and elongation in a controlled environment, allowing manipulation of signaling molecules and real-time observation.
Transgenic GFP imaging
Mice expressing green fluorescent protein in the ureteric bud enable visualization of branch elongation dynamics in whole organ culture or in vivo.
Immunohistochemistry and in situ hybridization
These methods detect the expression and localization of proteins and mRNAs involved in branch elongation, such as L1 and morphogenetic molecules.
Genetic lineage tracing
Lineage tracing using Cre-lox systems in mice can identify the cellular origins and fates of ureteric bud cells during elongation.
How CRISPR Can Be Used to Study GO:0060681 branch elongation involved in ureteric bud branching
Knockout
CRISPR knockout of candidate genes in ureteric bud cells or mouse models can reveal their requirement for branch elongation. For example, knocking out L1CAM or RET would test their roles in branching morphogenesis.
Point Mutation
Introducing disease-associated point mutations (e.g., in RET or PAX2) using CRISPR base editing or HDR can model human CAKUT and assess effects on branch elongation.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) into genes expressed in the ureteric bud allows live imaging of branch elongation, as demonstrated by transgenic GFP mice.
Overexpression
CRISPR activation (CRISPRa) or transgenic overexpression can test whether increasing a gene's activity enhances or disrupts branch elongation, providing gain-of-function insights.
How EDITGENE Supports branch elongation involved in ureteric bud branching Research
Researchers studying branch elongation involved in ureteric bud branching-related genes often need to determine whether a candidate gene is causally involved in this process. EDITGENE provides comprehensive CRISPR-based services to generate knockout, point-mutation, knock-in, and overexpression cell models, as well as CRISPR library screening and bioinformatics support, enabling precise functional dissection of genes in kidney development.
Contact EDITGENE today to design your custom CRISPR model for branch elongation involved in ureteric bud branching research.
Frequently Asked Questions About branch elongation involved in ureteric bud branching
What is GO:0060681?
GO:0060681 is the Gene Ontology term for branch elongation involved in ureteric bud branching, defined as the growth of a branch of the ureteric bud along its axis.
What genes are involved in branch elongation involved in ureteric bud branching?
Key genes include L1CAM, RET, GDNF, PAX2, HNF1B, and EYA1, among others, based on studies of kidney branching morphogenesis.
Why is ureteric bud branch elongation important?
It determines the architecture of the renal collecting duct system, and defects cause congenital kidney anomalies such as renal dysplasia and vesico-ureteric reflux.
How is branch elongation studied experimentally?
Researchers use in vitro isolated ureteric bud assays, GFP-transgenic mice, and organoid cultures to study branch elongation.
What diseases are associated with defective ureteric bud branching?
Congenital anomalies of the kidney and urinary tract, including renal dysplasia and vesico-ureteric reflux, are linked to defective branching.
What is the role of L1CAM in kidney branching?
L1CAM is a cell adhesion molecule that is developmentally regulated in renal epithelium and involved in kidney branching morphogenesis.
Can CRISPR be used to study branch elongation?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can be used to dissect gene function in ureteric bud branching.
What model organisms are used to study ureteric bud branching?
Mouse models, particularly transgenic GFP-ureteric bud mice, and in vitro isolated ureteric bud cultures are commonly used.
How does GDNF signaling affect branch elongation?
GDNF signaling through RET is a key inducer of ureteric bud outgrowth and branching, influencing elongation.
What are the research methods for studying GO:0060681?
Methods include in vitro branching assays, immunohistochemistry, in situ hybridization, lineage tracing, and RNA-seq.
Conclusion
GO:0060681, branch elongation involved in ureteric bud branching, is a critical biological process in kidney development that ensures proper formation of the collecting duct system. Research using in vitro assays, transgenic models, and CRISPR-based tools continues to uncover the molecular players and regulatory networks controlling this process. Understanding branch elongation not only sheds light on congenital kidney diseases but also informs regenerative medicine approaches for kidney repair.
References
- 1. al-Awqati Q et al.. 1998. Architectural patterns in branching morphogenesis in the kidney.. Kidney Int 54(6):1832-42 PMID: 9853247
- 2. Meyer TN et al.. 2004. Spatiotemporal regulation of morphogenetic molecules during in vitro branching of the isolated ureteric bud: toward a model of branching through budding in the developing kidney.. Dev Biol 275(1):44-67 PMID: 15464572
- 3. Srinivas S et al.. 1999. Expression of green fluorescent protein in the ureteric bud of transgenic mice: a new tool for the analysis of ureteric bud morphogenesis.. Dev Genet 24(3-4):241-51 PMID: 10322632
- 4. Debiec H et al.. 1998. The cell adhesion molecule L1 is developmentally regulated in the renal epithelium and is involved in kidney branching morphogenesis.. J Cell Biol 143(7):2067-79 PMID: 9864376
- 5. Murer L et al.. 2007. Embryology and genetics of primary vesico-ureteric reflux and associated renal dysplasia.. Pediatr Nephrol 22(6):788-97 PMID: 17216254
