Meeting Abstract

P2-139    Refining a method for identifying female reproductive stage including female sperm storage in bats using vaginal cytology MacDonald, LE*; Ruiz, D; Coomes, NM; Orr, TJ; New Mexico State University, Las Cruces, NM; New Mexico State University, Las Cruces, NM; New Mexico State University, Las Cruces, NM; New Mexico State University, Las Cruces, NM lmacdo@nmsu.edu

Many species of bats mate in the fall, but delay conception until spring by maintaining spermatozoa within the female’s reproductive tract. Current methods to identify female sperm storage (FSS) rely on dissection and microscopy to detect the presence of sperm. Alternatively, FSS has been inferred from indirect evidence of isolated females experiencing an ensuing pregnancy. However, detection of FSS while a bat is alive and actively storing sperm is essential for longitudinal studies. To determine if we could identify reproductive stage and FSS in female bats, we tested the use of vaginal lavages, a non-invasive cytological assessment of vaginal cells. Vaginal lavages are commonplace in the field of medicine but have only been applied in fewer than 40 non-human studies encompassing seven species, primarily rodents. Here we present data from a modified vaginal lavage method developed for mice. We collected samples from more than 10 female pallid bats (Antrozous pallidus). Using a modified Papanicolaou’s stain, we were able to identify the presence and relative abundance of nucleated epithelial cells, cornified squamous epithelial cells and leukocytes. From changes in cell typology, the reproductive stages of proestrus, estrus, metestrus, and diestrus could be determined. We present our modified protocol and discuss how identifying female reproductive stage, including FSS, can be factored into future research. A female’s reproductive state has important, yet often overlooked, effects on many aspects of an animal’s biology including immunology and bioenergetics, as well as clear implications in behavior and sexual selection. Being able to identify reproductive stages using methods such as described here is essential to factoring reproduction into future research. We anticipate the methods we present could be applied to many additional taxa.