Evidence for RNA or protein transport from somatic tissues to the male reproductive tract in mouse
- University of Massachusetts Medical School, United States
- Joslin Diabetes Center, United States
- Harvard University, United States
Abstract
The development of tools to manipulate the mouse genome, including knockout and transgenic technology, has revolutionized our ability to explore gene function in mammals. Moreover, for genes that are expressed in multiple tissues or at multiple stages of development, the use of tissue-specific expression of the Cre recombinase allows gene function to be perturbed in specific cell types and/or at specific times. However, it is well known that putative tissue-specific promoters often drive unanticipated 'off target' expression. In our efforts to explore the biology of the male reproductive tract, we unexpectedly found that expression of Cre in the central nervous system resulted in recombination in the epididymis, a tissue where sperm mature for ~1-2 weeks following the completion of testicular development. Remarkably, we not only observed reporter expression in the epididymis when Cre expression was driven from neuron-specific transgenes, but also when Cre expression in the brain was induced from an AAV vector carrying a Cre expression construct. A surprisingly wide range of Cre drivers - including six different neuronal promoters as well as the adipose-specific Adipoq Cre promoter - exhibited off target recombination in the epididymis, with a subset of drivers also exhibiting unexpected activity in other tissues such as the reproductive accessory glands. Using a combination of parabiosis and serum transfer experiments, we find evidence supporting the hypothesis that Cre may be trafficked from its cell of origin to the epididymis through the circulatory system. Together, our findings should motivate extreme caution when interpreting conditional alleles, and suggest the exciting possibility of inter-tissue RNA or protein trafficking in modulation of reproductive biology.
Data availability
A representative subset of the raw image data (with supporting metadata) will be made publicly available on acceptance. Source data for gels/blots has been provided.
Article and author information
Author details
Funding
Templeton World Charity Foundation (61350)
- Vera RInaldi
- Bethany C Berry
- Shweta Kukreja
- Oliver J Rando
National Institutes of Health (R01HD080224)
- Kathleen Desevin
- Fengyun Sun
- Oliver J Rando
National Institutes of Health (R01DA047678)
- Andrew R Tapper
National Institutes of Health (DP1AG063419)
- Kathleen Messemer
- Amy J Wagers
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All animal use was approved by the Institutional Animal Care and Use Committees of UMass Chan Medical School and Harvard Faculty of Arts and Sciences, under protocol PROTO202100029 to Dr. Oliver Rando and protocol 29014 awarded to Dr. Amy Wagers.
Copyright
© 2023, RInaldi et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
