Simple generation of hairless mice for <i>in vivo</i> imaging

Abstract

The in vivo imaging of mice makes it possible to analyze disease progress non-invasively through reporter gene expression. As the removal of hair improves the accuracy of in vivo imaging, gene-modified mice with a reporter gene are often crossed with Hos:HR-1 mutant mice homozygous for the spontaneous Hrhr mutation that exhibit a hair loss phenotype. However, it is time consuming to produce mice carrying both the reporter gene and mutant Hrhr gene by mating. In addition, there is a risk that genetic background of the gene-modified mice would be altered by mating. To resolve these issues, we established a simple method to generate hairless mice maintaining the original genetic background by CRISPR technology. First, we constructed the pX330 vector, which targets exon 3 of Hr. This DNA vector (5 ng/µl) was microinjected into the pronuclei of C57BL/6J mice. Induced Hr gene mutations were found in many founders (76.1%) and these mutations were heritable. Next, we performed in vivo imaging using these gene-modified hairless mice. As expected, luminescent objects in their body were detected by in vivo imaging. This study clearly showed that hairless mice could be simply generated by the CRISPR/Cas9 system, and this method may be useful for in vivo imaging studies with various gene-modified mice.

Effect of ultraviolet C emitted from KrCl excimer lamp with or without bandpass filter to mouse epidermis

“…Hos:HR-1 (Japan SLC, Inc., Hamamatsu, Japan) is a mutant mouse strain, which is homozygous for the spontaneous Hr hr mutation. This strain exhibits a hair loss phenotype; however, the mutation does not influence the nature of the skin [ 17 ]. In the present study, 7-week-old female Hos:HR-1 mice were used.…”

Methods for detecting PER2::LUCIFERASE bioluminescence rhythms in freely moving mice

“…Future studies to address this may include crossing transgenes onto an albino background to avoid the pigmentation and possibly even avoid the need for shaving. A hairless mouse might provide optimal background (Collaco andGeusz 2003, Izumi et al 2017) although hairless mice might still have skin pigmentation and can show other alterations in their phenotype (Hoshino et al 2017). Moreover, there are sex differences in the optical properties of murine skin to be considered in experimental design.…”

In Vivo Surface‐Enhanced Transmission Raman Spectroscopy under Maximum Permissible Exposure: Toward Photosafe Detection of Deep‐Seated Tumors

“…Depilation of animals is typically necessary prior to in vivo optical measurements to avoid strong light absorption, scattering, and autofluorescence interference of the hair, even at the NIR window. [ 42,43 ] Nevertheless, to highlight the non‐invasive detection capabilities of the TRS, we used unshaved mice for the in vivo measurements. As shown in Figure 5b, the abdominal‐dorsal thickness of the mice was about 1.5 cm.…”