In this study, a gadolinium-based contrast perfusion method was developed to selectively enhance the cerebral arteries in fixed mouse embryos

In this study, a gadolinium-based contrast perfusion method was developed to selectively enhance the cerebral arteries in fixed mouse embryos. the complete absence of the basilar artery. These results demonstrate that contrast-enhanced micro-MRI provides a powerful tool for analyzing vascular phenotypes in a variety of genetically manufactured mice. Keywords:angiogenesis, basilar artery, carotid artery, Gli2 mutant mice, vascular development During mammalian embryogenesis, the vasculature forms as a highly complex three-dimensional (3D) system of interconnected blood vessels that provide Rabbit Polyclonal to PROC (L chain, Cleaved-Leu179) the developing cells with essential nutrients, growth factors, and oxygen. Studies using genetically manufactured mice have offered critical data within the genetic and molecular factors controlling vascular development during embryogenesis and also during disease progression involving abnormal formation of blood vessels. In these studies, quantitative 3D analysis of vascular patterns is definitely seldom performed since popular histologic methods are inherently two dimensional and prone to sectioning artifacts, making 3D reconstructions hard. Volumetric imaging methods such as magnetic resonance micro-imaging (micro-MRI) could provide powerful new tools to study vascular patterning in both normal and mutant mouse embryos. Vascular development during embryogenesis can be divided into two important processes: vasculogenesis and angiogenesis. The earliest step, vasculogenesis, entails the ICA recruitment and assembly of endothelial-cell precursors, called angioblasts, into a main vascular plexus (1). These primitive blood vessels are then prolonged and elaborated by the process of angiogenesis, which involves cell proliferation, differentiation of the arterial and venous parts, and the establishment of the final 3D patterns of the vascular networks (2). While vasculogenesis is definitely a process that occurs only during early embryonic development, angiogenesis is an ongoing process that can also happen after birth, depending on the needs of different cells, which can be advantageous, as with angiogenesis after ischemia (3), or pathologic, as with tumor angiogenesis (4). The development of the mammalian vasculature results in apparently stereotypical patterns in a number of vascular subsystems, including the cerebral arteries. However 3D vascular patterning during mind development has not been investigated in detail, in large part due to the lack of analytical tools. We are particularly interested in analyzing the 3D patterns of the cerebral arterial inputs and how these patterns switch during normal development, and in mouse mutants after genetic alterations that disrupt vascular patterning. The primary vascular inputs into the developing mind are the basilar artery that perfuses the more posterior parts of the brain and the carotid arteries that supply blood to the more anterior mind regions. With this statement, we demonstrate contrast-enhanced ICA micro-MRI methods that enable 3D analysis of both cerebral arterial systems over a ICA wide range of embryonic phases. == Materials and Methods == == Animals == All methods involving mice were authorized by the Institutional Animal Care and Use Committee at New York University School of Medicine. Timed-pregnant ICR strain mice (Taconic Farms, Germantown, NY) were utilized for studies of normal embryonic development, where the stage was denoted as the embryonic day time (E) following recognition of a vaginal plug after over night mating (E0.5 was defined as noon of the plug day time). Embryos were analyzed at phases between E10.5 and E17.5. For mutant analysis,Gli2heterozygous mutant mice were bred to generateGli2-/-homozygous null mutant embryos, ICA as well asGli2+/-(heterozygous mutant) andGli2+/+(crazy ICA type) littermate settings. Polymerase chain reaction of embryo yolk sac DNA was used to identify genotypes, using primers forNeoand wild-typeGli2, as previously explained (5). == Embryo Preparation for Micro-MRI == The.