Defects in efferent duct multiciliogenesis underlie male infertility in GEMC1-, MCIDAS- or CCNO-deficient mice
DEVELOPMENT
Authors: Terre, Berta; Lewis, Michael; Gil-Gomez, Gabriel; Han, Zhiyuan; Lu, Hao; Aguilera, Monica; Prats, Neus; Roy, Sudipto; Zhao, Haotian; Stracker, Travis H.
Abstract
GEMC1 and MCIDAS are geminin family proteins that transcriptionally activate E2F4/5-target genes during multiciliogenesis, including Foxj1 and Ccno. Male mice that lacked Gemc1, Mcidas or Ccno were found to be infertile, but the origin of this defect has remained unclear. Here, we show that all three genes are necessary for the generation of functional multiciliated cells in the efferent ducts that are required for spermatozoa to enter the epididymis. In mice that are mutant for Gemc1, Mcidas or Ccno, we observed a similar spectrum of phenotypes, including thinning of the seminiferous tubule epithelia, dilation of the rate testes, sperm agglutinations in the efferent ducts and lack of spermatozoa in the epididymis (azoospermia). These data suggest that defective efferent duct development is the dominant cause of male infertility in these mouse models, and this likely extends to individuals with the ciliopathy reduced generation of multiple motile cilia with mutations in MCIDAS and CCNO.
Aryl hydrocarbon receptor is required for optimal B-cell proliferation
EMBO JOURNAL
Authors: Villa, Matteo; Gialitakis, Manolis; Tolaini, Mauro; Ahlfors, Helena; Henderson, Colin J.; Wolf, C. Roland; Brink, Robert; Stockinger, Brigitta
Abstract
The aryl hydrocarbon receptor (AhR), a transcription factor known for mediating xenobiotic toxicity, is expressed in B cells, which are known targets for environmental pollutants. However, it is unclear what the physiological functions of AhR in B cells are. We show here that expression of Ahr in B cells is up-regulated upon B-cell receptor (BCR) engagement and IL-4 treatment. Addition of a natural ligand of AhR, FICZ, induces AhR translocation to the nucleus and transcription of the AhR target gene Cyp1a1, showing that the AhR pathway is functional in B cells. AhR-deficient (Ahr(-/-)) B cells proliferate less than AhR-sufficient (Ahr(+/+)) cells following invitro BCR stimulation and invivo adoptive transfer models confirmed that Ahr(-/-) B cells are outcompeted by Ahr(+/+) cells. Transcriptome comparison of AhR-deficient and AhR-sufficient B cells identified cyclin O (Ccno), a direct target of AhR, as a top candidate affected by AhR deficiency.