Dwarfism Research Today is a free monthly online journal that collates and summarizes the latest research about Dwarfism, including details on genetics, diet, mental and motor development.

Plasma IGF-1 is negatively correlated with body mass in a comparison of 36 mammalian species.

Stuart JA, Page MM

Department of Biological Sciences, Brock University, St. Catharines, ON, Canada, L2S 3A1.

In mammals, insulin-like growth factor-1 (IGF-1) is positively correlated with adult body mass, in comparisons made within a given species. In mice, IGF-1 deficiency is associated with dwarfism, whereas IGF-1 overproduction in transgenic animals causes gigantism. Surprisingly, the opposite is true in an inter-species context. We collected published plasma total IGF-1 data for adults of 36 mammalian species and analyzed it with respect to body mass. In contrast to the intra-species observation, this analysis revealed a significant negative correlation of plasma IGF-1 with body mass. Interestingly, IGF-1 is negatively correlated with longevity, and suppression of IGF-1 signalling in worms, flies and mice increases lifespan. Smaller mouse strains, for example, tend to have lower plasma IGF-1 levels and to be longer-lived. However, when plasma total IGF-1 was analyzed relative to the maximum lifespans of the 36 species examined here, there was no statistically significant correlation. Low plasma IGF-1 levels in larger mammalian species may be physiologically significant, considering the roles of this hormone in metabolism, tissue regeneration, and cancer incidence.

Published 25 August 2010 in Mech Ageing Dev.
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Articles on Dwarfism published 19 August 2010:

COL9A2 and COL9A3 mutations in canine autosomal recessive oculoskeletal dysplasia.   Mamm Genome, 21(7): 398-408.

Oculoskeletal dysplasia segregates as an autosomal recessive trait in the Labrador retriever and Samoyed canine breeds, in which the causative loci have been termed drd1 and drd2, respectively. Affected dogs exhibit short-limbed dwarfism and severe ocular defects. The disease phenotype resembles human hereditary arthro-ophthalmopathies such as Stickler and Marshall syndromes, although these disorders are usually dominant. Linkage studies mapped drd1 to canine chromosome 24 and drd2 to canine ... [Abstract] [Full-text]

Articles on Dwarfism published 17 August 2010:

Intragenic suppression of a trafficking-defective brassinosteroid receptor mutant in Arabidopsis.   Genetics, 185(4): 1283-96.

The cell surface receptor kinase BRASSINOSTEROID-INSENSITIVE-1 (BRI1) is the major receptor for steroid hormones in Arabidopsis. Plants homozygous for loss-of-function mutations in BRI1 display a reduction in the size of vegetative organs, resulting in dwarfism. The recessive bri1-5 mutation produces receptors that do not accumulate to wild-type levels and are retained mainly in the endoplasmic reticulum. We have isolated a dominant suppressor of the dwarf phenotype of bri1-5 plants. We show ... [Abstract] [Full-text]

Delayed bone age due to a dual effect of FGFR3 mutation in Achondroplasia.   Bone.

Achondroplasia (ACH), the most common form of human dwarfism is caused by a mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene, resulting in constitutive activation of the receptor. Typical radiological features include shortening of the tubular bones and macrocephaly, due to disruption of endochondral ossification. Consequently, FGFR3 has been described as a negative regulator of bone growth. Studying a large cohort of ACH patients, a delay in bone age was observed shortly after ... [Abstract] [Full-text]

Articles on Dwarfism published 16 August 2010:

Brachytic2/ZmABCB1 functions in IAA export from intercalary meristems.   J Exp Bot, 61(13): 3689-96.

Dwarfism traits in Zea mays are regulated by multiple factors including the hormone auxin. Dwarf brachytic2 (br2) mutants harbour lesions in the gene encoding an orthologue of Arabidopsis thaliana ABCB1 which functions in auxin efflux out of meristematic regions in the shoot and root. br2 mesocotyls and coleoptiles exhibit reduced auxin transport. However, the dwarf stature of br2 derives from shortened lower internodes whilst the upper portion of the plant is completely normal. As such, it is ... [Abstract] [Full-text]

Articles on Dwarfism published 6 August 2010:

Integrative study on proteomics, molecular physiology, and genetics reveals an accumulation of cyclophilin-like protein, TaCYP20-2, leading to an increase of Rht protein and dwarf in a novel GA-insensitive mutant (gaid) in Wheat.   J Proteome Res, 9(8): 4242-53.

Dwarfism with a "Green Revolution" phenotype is a desirable agronomic trait for crop cultivators as associated with increased yield, improved lodging resistance and higher fertility. Few dwarf mutants of hexaploid wheat (Triticum aestivum), except for Rht-B1 and Rht-D1, have been identified. Here, we report on a novel dwarf natural wheat mutant, which is identified as a gibberellic acid (GA)-insensitive dwarf (gaid) mutant for its semidominant blocking GA signaling pathway. ... [Abstract] [Full-text]

Articles on Dwarfism published 5 August 2010:

Maternal isodisomy for chromosome 9 causing homozygosity for a novel FOXE1 mutation in syndromic congenital hypothyroidism.   J Clin Endocrinol Metab, 95(8): 4031-6.

CONTEXT: Homozygous loss-of-function mutations in forkhead box E1/thyroid transcription factor 2 (FOXE1/TTF-2) cause syndromic congenital hypothyroidism, with thyroid dysgenesis, cleft palate, spiky hair, and variable choanal atresia and bifid epiglottis in three cases reported hitherto. We have elucidated the molecular basis of the disorder in a female with a similar clinical phenotype, born to nonconsanguineous parents. OBJECTIVE AND DESIGN: The FOXE1 gene, located on chromosome 9q22, was ... [Abstract] [Full-text]

Articles on Dwarfism published 3 August 2010:

Gastrointestinal tract disorder in natriuretic peptide receptor B gene mutant mice.   Am J Pathol, 177(2): 822-8.

Natriuretic peptide receptor B (NPR-B), which has high affinity for C-type natriuretic peptide (CNP) and synthesizes intracellular cGMP, may be involved in gastrointestinal tract (GIT) regulation. A mutant allele of the NPR-B-encoding gene (Npr2) is responsible for the phenotype of the short-limb dwarfism (SLW) mouse. Homozygosity for this autosomal-recessive gene (slw/slw) leads to dwarfism and death before weaning because of milk retention in the stomach and intestinal distention. To ... [Abstract] [Full-text]

Articles on Dwarfism published 2 August 2010:

A novel role for the centrosomal protein, pericentrin, in regulation of insulin secretory vesicle docking in mouse pancreatic beta-cells.   PLoS One, 5(7): e11812.

The centrosome is important for microtubule organization and cell cycle progression in animal cells. Recently, mutations in the centrosomal protein, pericentrin, have been linked to human microcephalic osteodysplastic primordial dwarfism (MOPD II), a rare genetic disease characterized by severe growth retardation and early onset of type 2 diabetes among other clinical manifestations. While the link between centrosomal and cell cycle defects may account for growth deficiencies, the mechanism ... [Abstract] [Full-text]

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