Sequential expression of annexin A5 in the vasculature and skeletal elements during mouse development

Abstract

Annexin A5 (annexin V, anchorin CII) represents the prototype member of the large annexin family, characterized by its ability to interact with phospholipids in a calcium-dependent manner and to form calcium-specific ion channels. Despite intense biochemical analysis, the in vivo expression and function of this annexin during mouse development, still remains unclear. Immunohistochemistry, in situ hybridization and reporter gene expression were used to define expression of annexin A5 during early mouse development. First, annexin A5 expression is associated with the developing vascular system. Later, expression is detected within the notochord and found in parallel to the differentiation of cartilage and bone. Therefore, expression of the Anxa5 gene may represent a novel marker characterizing cell lineages involved in the development of the vascular as well as the skeletal system.

Collagen IV is essential for basement membrane stability but dispensable for initiation of its assembly during early development

“…2C) also suggested that stability and internal organization of embryonic vascular basement membranes is perturbed. To test whether collagen IV deficiency also interferes with vascular development, we used the recently described Anxa5-lacZ transgene, which specifically detects perivascular cells, to visualize most blood vessels and capillaries in collagen IV mutant embryos (Brachvogel et al, 2001). β-gal staining demonstrated that the overall formation of the vasculature was indistinguishable between collagen IV mutant and wild-type embryos, as major vascular elements and the capillary networks in the embryo (Fig.…”

“…The Anxa5-lacZ fusiongene was generated by homologous recombination in ES cells and the derived mouse strain showed no obvious altered phenotype (Brachvogel et al, 2001;Brachvogel et al, 2003). By mating mice heterozygous for the Col4a1/2 mutation with Anxa5 lacZ/lacZ mice, a strain was established with Col4a1/2 +/-Anxa5 lacZ/lacZ genotype and used for generating embryos with various Col4a1/2 genotypes on a heterozygous Anxa5 lacZ/+ background.…”

“…By mating mice heterozygous for the Col4a1/2 mutation with Anxa5 lacZ/lacZ mice, a strain was established with Col4a1/2 +/-Anxa5 lacZ/lacZ genotype and used for generating embryos with various Col4a1/2 genotypes on a heterozygous Anxa5 lacZ/+ background. Time-staged embryos were isolated, genotyped, stained for β-gal activity and used for vibratome sectioning as described (Brachvogel et al, 2001).…”

Perivascular cells expressing annexin A5 define a novel mesenchymal stem cell-like population with the capacity to differentiate into multiple mesenchymal lineages

“…Initial studies showed that this fusion gene is expressed in cells associated with the vascular network of embryos (E10.5-E14.5) (Brachvogel et al, 2001). To define the onset of expression during development, we analyzed Anxa5-lacZ + expression during early embryogenesis (E5.5-E9.5).…”

“…Although numerous functions of annexin A5 have been described in vitro, its in vivo role still remains unclear (Brachvogel et al, 2003). Expression analysis of the annexin A5 gene (Anxa5) by the use of an Anxa5-lacZ fusion gene in vivo showed that this gene is expressed in vasculatureassociated cells and at later stages (E13.5-P1) in mesenchymal condensations, chondrocytes as well as all skeletal elements (Brachvogel et al, 2001).…”