Related Experiment Video
Updated: Aug 13, 2026
12:47
Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease
Published on: February 3, 2012
Galphas transcripts are biallelically expressed in the human kidney cortex: implications for pseudohypoparathyroidism
H Zheng1, G Radeva, J A McCann
1Department of Pediatrics, McGill University, Montréal, Québec, Canada H3Z 2Z3.
The Journal of Clinical Endocrinology and Metabolism
|October 16, 2001
Summary
Pseudohypoparathyroidism type 1b involves kidney resistance to parathyroid hormone (PTH). Studies suggest abnormal imprinting of GNAS1 locus regions, not just Galphas, causes this condition.
Area of Science:
- Endocrinology
- Genetics
- Molecular Biology
Background:
- Pseudohypoparathyroidism type 1b (PHP1b) presents with renal resistance to parathyroid hormone (PTH).
- Previous research suggested paternal imprinting of GNAS1 affecting Galphas in renal proximal tubules causes PHP1b.
- Albright's hereditary osteodystrophy and other endocrine issues are typically absent in PHP1b.
Purpose of the Study:
- To investigate the allelic expression of GNAS1 in human fetal kidney cortex.
- To determine if paternal imprinting of Galphas is the sole cause of PHP1b.
Main Methods:
- Analysis of GNAS1 allelic expression using RT-PCR in human fetal kidney cortex samples.
- Comparison of Galphas transcript expression with known imprinted transcripts (exon 1A, XLalphas, NESP).
Main Results:
- Galphas transcripts demonstrated biallelic expression in the human kidney cortex.
- This contrasts with the parent-specific (imprinted) expression of other GNAS1-related transcripts like exon 1A, XLalphas, and NESP.
Conclusions:
- Abnormal imprinting of alternative regions within the GNAS1 locus is implicated in PHP1b.
- The findings challenge the hypothesis of solely paternal imprinting of Galphas as the cause of PHP1b.
Related Concept Videos
01:58Cell Specific Gene Expression
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
00:59The Parathyroid Glands
The two pairs of parathyroid glands embedded within the posterior surface of the thyroid gland are restricted by a dense capsule around them. These glands comprise two distinct cell populations—parathyroid oxyphil and parathyroid principal cells- pivotal in calcium homeostasis.
Oxyphil cells, whose functions remain elusive, emerge during late puberty, adding a layer of complexity to the parathyroid gland's intricacies. In contrast, principal parathyroid cells undertake a vital role by producing...
Oxyphil cells, whose functions remain elusive, emerge during late puberty, adding a layer of complexity to the parathyroid gland's intricacies. In contrast, principal parathyroid cells undertake a vital role by producing...
01:10Nephrons
The kidneys are intricate organs with millions of working units known as nephrons. Each nephron features two major structures: the renal corpuscle, which facilitates blood plasma filtration, and the renal tubule, which handles the glomerular filtrate. Blood supply is directly linked to the nephrons. The renal corpuscle consists of the glomerulus, a capillary network, and the Bowman's capsule, a double-walled epithelial structure that encases the glomerulus. The filtering of blood plasma happens...
01:20Renal Corpuscle
The glomerulus and Bowman's capsule are two essential components of the nephron, which is the functional unit of the kidney. These microscopic structures play a critical role in the process of blood filtration to produce urine.
Glomerulus: Structure and Function
The glomerulus is a tiny, intricate network of capillaries located at the beginning of the nephron. It's enveloped by the Bowman's capsule and receives its blood supply from an afferent arteriole, which divides into numerous capillaries...
Glomerulus: Structure and Function
The glomerulus is a tiny, intricate network of capillaries located at the beginning of the nephron. It's enveloped by the Bowman's capsule and receives its blood supply from an afferent arteriole, which divides into numerous capillaries...
01:27Roles of Electrolytes: Calcium and Phosphate
Calcium and phosphate are essential electrolytes in the human body, with calcium being the most abundant mineral. Around 99% of the body's calcium is stored in the skeleton and teeth, forming a crystal lattice of mineral salts in combination with phosphates. Calcium plays crucial roles in various bodily functions such as blood clotting, neurotransmitter release, muscle tone maintenance, and nervous and muscle tissue excitability.
The calcium concentration in blood plasma is primarily regulated...
The calcium concentration in blood plasma is primarily regulated...
01:22Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion
The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport...