Hmga1/Hmga2 double knock-out mice display a "superpygmy" phenotype.

Authors :: Federico A
Forzati F
Esposito F
Arra C
Palma G
Barbieri A
Palmieri D
Fedele M
Pierantoni GM
De Martino I
Fusco A
Source :: Biology open [Biol Open] 2014 Apr 11; Vol. 3 (5), pp. 372-8. Date of Electronic Publication: 2014 Apr 11.
Publication Year :: 2014
Abstract: The HMGA1 and HMGA2 genes code for proteins belonging to the High Mobility Group A family. Several genes are negatively or positively regulated by both these proteins, but a number of genes are specifically regulated by only one of them. Indeed, knock-out of the Hmga1 and Hmga2 genes leads to different phenotypes: cardiac hypertrophy and type 2 diabetes in the former case, and a large reduction in body size and amount of fat tissue in the latter case. Therefore, to better elucidate the functions of the Hmga genes, we crossed Hmga1-null mice with mice null for Hmga2. The Hmga1(-/-)/Hmga2(-/-) mice showed reduced vitality and a very small size (75% smaller than the wild-type mice); they were even smaller than pygmy Hmga2-null mice. The drastic reduction in E2F1 activity, and consequently in the expression of the E2F-dependent genes involved in cell cycle regulation, likely accounts for some phenotypic features of the Hmga1(-/-)/Hmga2(-/-) mice.<br /> (© 2014. Published by The Company of Biologists Ltd.)