DISTINCT ALPHA(7A)BETA(1) AND ALPHA(7B)BETA(1) INTEGRIN EXPRESSION PATTERNS DURING MOUSE DEVELOPMENT - ALPHA(7A) IS RESTRICTED TO SKELETAL-MUSCLE BUT ALPHA(7B) IS EXPRESSED IN STRIATED-MUSCLE, VASCULATURE, ANDNERVOUS-SYSTEM

Citation
T. Velling et al., DISTINCT ALPHA(7A)BETA(1) AND ALPHA(7B)BETA(1) INTEGRIN EXPRESSION PATTERNS DURING MOUSE DEVELOPMENT - ALPHA(7A) IS RESTRICTED TO SKELETAL-MUSCLE BUT ALPHA(7B) IS EXPRESSED IN STRIATED-MUSCLE, VASCULATURE, ANDNERVOUS-SYSTEM, Developmental dynamics, 207(4), 1996, pp. 355-371
Citations number
55
Categorie Soggetti
Developmental Biology","Anatomy & Morphology
Journal title
ISSN journal
10588388
Volume
207
Issue
4
Year of publication
1996
Pages
355 - 371
Database
ISI
SICI code
1058-8388(1996)207:4<355:DAAAIE>2.0.ZU;2-R
Abstract
The laminin binding alpha(7) beta(1) integrin has been described as a major integrin in skeletal muscle. The RNA coding for the cytoplasmic domain of alpha(7) integrin undergoes alternative splicing to generate two major forms, denoted alpha(7A) and alpha(7B) In the current paper , we have examined the developmental expression patterns of the alpha( 7A) and alpha(7B) splice variants in the mouse, The alpha(7) integrin expression is compared to that of the nonintegrin laminin receptor dys troglycan and to that of laminin-alpha 1 and laminin-alpha 2 chains, a lpha(7A) integrin was found by in situ hybridization to be specific to skeletal muscle, Antibodies specific for alpha(7B) integrin and in si tu hybridization revealed the presence of alpha(7) mRNA and alpha(7B) protein in the E10 myotome and later in primary and secondary myotubes , In the heart, alpha(7B) integrin was not detectable in the endocardi um or myocardium during embryonic and fetal heart development, Norther n blot analysis and immunohistochemistry revealed a postnatal inductio n of alpha(7B) in the myocardium, In addition to striated muscle, alph a(7B) integrin was localized to previously unreported nonmuscle locati ons such as a subset of vascular endothelia and restricted sites in th e nervous system. Comparison of the alpha(7) integrin expression patte rn with that of different laminin isoforms and dystroglycan revealed a coordinated temporal expression of dystroglycan, alpha(7) integrin, a nd laminin-alpha 2, but not laminin-alpha 1, in the forming skeletal m uscle, We conclude that the alpha(7A) and alpha(7B) integrin variants are expressed in a developmentally regulated, tissue-specific pattern suggesting different functions for the two splice forms. (C) 1996 Wile y-Liss, Inc.