Equipment and Methods for Concurrently Housing Germfree and Gnotobiotic Mice in the Same Room.

Here, we combined the use of 2 technologies that have not previously been used together-a positively pressurized isolator IVC (IsoIVC-P) and a modular isolator with integrated vaporized hydrogen peroxide (VHP) technology???to develop highly tractable and scalable methods to support long-term maintenance of germfree mouse colonies and the concurrent use of germfree and gnotobiotic mice in the same room. This space-efficient system increases the practicality of microbiome studies. Specifically, the exterior surfaces of microbially similar IsoIVC-P were sterilized by using VHP prior to opening the cages and handling the mice therein. This space-efficient system increases the feasibility of microbiome studies. After over 74 wk of experimentation and handling equivalent to more than 1,379,693 germfree mouse-days, we determined that the method and practices we developed have a weekly performance metric of 0.0001 sterility breaks per husbandry unit; this rate is comparable to the isolator 'gold standard.' These data were achieved without adverse incidents while maintaining an Altered Schaedler Flora colony and multiple gnotobiotic studies involving fecal microbial transplants in the same room. Our novel IsoIVC-P???VHP workstation housing system thus improves microbiome research efficiency, eliminates hazards, and reduces risks associated with traditional methods.

Histology and functional morphology of the oviduct of an oviparous snake, Diadophis punctatus.

Oviductal functional morphology remains poorly understood in oviparous snakes, particularly in regard to oviductal formation of albumen and the eggshell and to sperm storage. The oviduct of Diadophis punctatus was examined using histology and scanning electron microscopy to determine oviductal functional morphology throughout the reproductive cycle. The oviduct is composed of four morphologically distinct regions: infundibulum, uterine tube, uterus, and vagina. The infundibulum is thin, flaccid, and lined with simple ciliated cuboidal epithelial cells. The tube contains ciliated and secretory epithelial cells, which reach a maximum height and hypertrophy during early gravidity and produce glycosaminoglycans. The posterior portion of the tube contains temporary sperm storage receptacles. The uterus retains eggs throughout gestation and secretes the eggshell constituents. The endometrial glands of the uterus hypertrophy during vitellogenesis and become depleted of the secretory granules during gravidity. The functional morphology of the oviduct therefore shows cyclical changes that are correlated with eggshell formation. The vagina consists of thick longitudinal and circular smooth muscle layers, which may serve in retention of eggs during gestation. Furthermore, the vagina contains long furrows in the mucosa that serve as sperm storage receptacles. These receptacles store sperm following fall mating and overwintering, whereas the receptacles in the tube are utilized briefly during vitellogenesis just prior to ovulation. © 1996 Wiley-Liss, Inc.