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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.03.029 Byline: Su Hao Lo Keywords: Focal adhesion; Cartilage; Knockout mouse; Mutant fly Abstract: The cytoplasmic side of focal adhesions is comprised of large molecular complexes that link transmembrane receptors, such as integrins, to the actin cytoskeleton and mediate signals modulating cell attachment, migration, proliferation, differentiation, and gene expression. These complexes are heterogeneous and dynamic structures that are apparent targets of regulatory signals that control the function of focal adhesions. Recent studies using genetic approaches in invertebrate and vertebrate systems have begun to reveal the structure and function of these complexes in vivo. Author Affiliation: Center for Tissue Regeneration and Repair, Department of Orthopaedic Surgery and Cancer Center, University of California-Davis, Davis, 4635 Second Avenue, Room 2000, Sacramento, CA 95817, USA Article History: Received 21 December 2005; Revised 22 March 2006; Accepted 27 March 2006

Tensin family is a group of focal adhesion proteins that interact with integrins, actin, and phosphotyrosine-containing proteins. To explore the in vivo functions of a new member of the family, tensin3, we have generated mutant mice with a disrupted tensin3 gene. Inactivation of tensin3 resulted in growth retardation and postnatal lethality in one third of the homozygous mutants. Histological analysis of those mutants showed incomplete development of the small intestine, lung, and bone. Villus formation in the small intestine was affected and cells migrated slower in the runt mutants. Their lungs also displayed enlarged air space suggesting defects in alveogenesis. In addition, the resting zone was thicker and fewer proliferating cells were present in the growth plates of tensin[3.sup.-/-] tibiae. These observations indicate that tensin3 is essential for normal development and functions of the small intestine, lung, and bone. These phenotypes of the runt tensin[3.sup.-/-] mice are similar to some clinical features of Silver-Russell syndrome (SRS) which is a genetically inherited defect. About 10% of SRS cases have been linked to abnormality in chromosome 7p11.2-13, where human tensin3 gene is located, suggesting a potential link between tensin3 and SRS. Keywords: Tensin; Focal adhesion; Growth retardation; Postnatal lethality; Alveogenesis; Growth plates; Silver-Russell syndrome