High impact information on nrp1a

• To examine this hypothesis directly, expression of sema3a1 and/or nrp1a was manipulated in several ways [1].
• However, combined injections of neuropilin-1a morpholino, at a concentration that did not elicit axonal aberrations when injected alone, with VEGF, semaphorin 3A1, or semaphorin 3A2 morpholinos synergistically increased the proportion of embryos showing aberrant motor axon growth [2].
• Here, we show strong expression of neuropilin-1a in primary motor neurons in the trunk of embryonic zebrafish [2].
• In addition, neuropilin-1a morpholino treatment disturbed normal formation of blood vessels in the trunk of 24 hours postfertilization embryos, as shown by microangiography [2].
• These phenotypes could be partially rescued by co-injecting neuropilin-1a mRNA [2].

Anatomical context of nrp1a

• Zebrafish nrp1a is expressed in the neural tube including telencephalon, epithalamus, cells along the axonal trajectory of the posterior commissure and the medial longitudinal fascicle, hindbrain neurons, vagus motor neurons and spinal motoneurons [3].
• Indeed, nrp1a, which probably encodes a component of the Sema3a1 receptor, is specifically expressed by CaP during the early part of its outgrowth but not during later stages when extending into sema3a1-expressing muscle cells [1].
• Reducing the expression of neuropilin-1a using antisense morpholino oligonucleotides induced aberrant branching of motor nerves, additional exit points of motor nerves from the spinal cord, and migration of neurons out of the spinal cord along the motor axon pathway in a dose-dependent manner [2].

Other interactions of nrp1a

• Previously, we described the isolation and characterization of the first zebrafish neuropilin gene, which we now call nrp1a, and found its protein to be a mediator of vascular endothelial growth factor (VEGF)-dependent angiogenesis [Proc. Natl Acad. Sci. USA 99 (2002) 10470] [4].
• Knockdown of nrp1a, nrp1b, and nrp2a resulted in improper arteriovenous connections and irregular intersegmental vessel patterning, indicating that these Nrps function in the same process [5].

Analytical, diagnostic and therapeutic context of nrp1a

• Whole-mount in situ hybridization showed that transcripts for znrp1 during embryonic and early larval development were detected mainly in neuronal and vascular tissues [6].

References