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. 2009 Jul:Appendix 4:Appendix 4I.
doi: 10.1002/0471142301.nsa04is48.

Assessing reproductive status/stages in mice

Claudia S Caligioni  1
Affiliations

Assessing reproductive status/stages in mice

Claudia S Caligioni. Curr Protoc Neurosci. 2009 Jul.

Abstract

The short reproductive cycle length observed in rodents, called the estrous cycle, makes them an ideal animal model for investigation of changes that occur during the reproductive cycle. Most of the data in the literature about the estrous cycle is obtained from rats because they are easily manipulated and they exhibit a clear and well-defined estrous cycle. However, the increased number of experiments using knockout mice requires identification of their estrous cycle as well, since (in)fertility issues may arise. In mice, like rats, the identification of the stage of estrous cycle is based on the proportion of cell types observed in the vaginal secretion. The aim of this unit is to provide guidelines for quickly and accurately determining estrous cycle phases in mice.

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Figures

Figure 1
Figure 1
Photomicrographs of unstained vaginal secretion from mice at (A) pro-estrus, predominantly consisting of nucleated epithelial cells; (B) estrus, with anucleated cornified cells; (C) metestrus, consisting of the three types of cell, leukocytes, cornified, and nucleated epithelial cells; and (D) diestrus, consisting predominantly of leucocytes. Nucleated epithelial cells (N), leucocytes (L), cornified cell (C).
Figure 2
Figure 2
Proper means of holding a mouse for vaginal opening analysis and for the collection of vaginal secretion. Using the non-dominant hand, grasp the loose skin at the nape of the neck between one's thumb and forefinger and restrain the animal with one hand. Then invert the animal in the palm of the hand and place the tail between the handler's fourth and fifth fingers.
Figure 3
Figure 3
Vaginal opening in mice at approximately 26 days old, showing closed vaginal cavity (A, B) and opened vaginal cavity (C, D).
Figure 4
Figure 4
Collection of vaginal secretion in mice. After the female mouse has been restrained with the non-dominant hand of the handler, using the dominant hand, the tip of plastic pipette (∼5mm) filled with saline 0.9% or PBS is introduced in the vagina of the mouse (a, detail in b) and the liquid is flushed to collect the sample.
Figure 5
Figure 5
Plastic pipette filled with saline 0.9% (a) with a detail of the tip (b). Vaginal fluid is placed on a printed slide (c) for further analysis on microscope.
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References

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