So many bat puns, so hard to choose just one for the headline…

March’s issue of Cold Spring Harbor Protocols includes two sets of Emerging Model Organism articles with protocols. The first set, on Darwin’s Finches, is covered here. The second set is on the Short-Tailed Fruit Bat (Carollia perspicillata), and a bat embryo is featured on our cover. There are at least 1,116 species of bats, comprising >20% of all living mammalian species. Their abundance and diversity suggests that further study would give us a more balanced and comprehensive view of mammalian biology.
The Short-Tailed Fruit Bat Carollia perspicillata: A Model for Studies in Reproduction and Development is contributed by Richard Behringer, Chris Cretekos and John Rasweiler. This group has done some fascinating recent work using the bat as a comparative model for limb development, asking why a mouse makes a front leg where a bat makes a wing. Interesting morphological features like wings are just one reason among many to study bats as the authors point out:

Among the interesting features of the early embryogenesis of Carollia are development to the blastocyst stage and shedding of the zona pellucida in the oviducts, formation of reticulated endoderm during implantation (as in humans), development of an unusually large inner cell mass (ICM), disposition of endoderm and Reichert’s membrane around all or nearly all of the ICM, extensive apoptosis of epiblast cells during amniogenesis, and formation of a planar embryo at the primitive-streak stage (in contrast to the cup-shaped embryo of rodents) (Badwaik et al. 1997). Carollia is also unusual among mammals in that it sometimes takes embryos into prolonged periods of delay (diapause) after implantation, at the primitive-streak stage, which can last from weeks to months. This delay period occurs seasonally in the wild, but in response to stress in captivity (Rasweiler and Badwaik 1997), and is associated with major alterations in trophoblastic differentiation and placental development (Badwaik and Rasweiler 2001). The endocrine control of the delay remains to be elucidated.

Along with a general primer on the use of bats in the lab, Behringer and colleagues have also supplied protocols for feeding, generating timed pregnancies, collection of bats from the wild, collection of embryos, fixation and storage of embryos, staining of cartilage and bone, whole-mount in situ hybridization and whole-mount immunohistochemistry (the latter two providing my title on methods for visualizing bat signals, for which I apologize).