Mammalian Fused is essential for sperm head shaping and periaxonemal structure formation during spermatogenesis.

During mammalian spermatogenesis, the diploid spermatogonia mature into haploid spermatozoa through a highly controlled process of mitosis, meiosis and post-meiotic morphological remodeling (spermiogenesis). Despite important progress made in this area, the molecular mechanisms underpinning this transformation are poorly understood. Our analysis of the expression and function of the putative serine-threonine kinase Fused (Fu) provides critical insight into key steps in spermatogenesis.

Fused (Stk36) is a ciliary protein required for central pair assembly and motile cilia orientation in the mammalian oviduct.

Background: Motile cilia on the inner lining of the oviductal epithelium play a central role in ovum transport toward the uterus and subsequent fertilization by sperm. While the basic ultrastructure of 9+2 motile cilia (nine peripheral microtubule doublets surrounding a central pair) has been characterized, many important steps of ciliogenesis remain poorly understood.

Results: Our previous studies on mammalian Fused (Fu) (Stk36), a putative serine-threonine kinase, reveal a critical function of Fu in central pair construction and cilia orientation of motile cilia that line the tracheal and ependymal epithelia.

Hedgehog signaling from the primary cilium to the nucleus: an emerging picture of ciliary localization, trafficking and transduction.

The unexpected connection between cilia and signaling is one of the most exciting developments in cell biology in the past decade. In particular, the Hedgehog (Hh) signaling pathway relies on the primary cilium to regulate tissue patterning and homeostasis in vertebrates. A central question is how ciliary localization and trafficking of Hh pathway components lead to pathway activation and regulation.

The path to chemotaxis and transcription is smoothened.

The Hedgehog (Hh) family of secreted proteins governs the development of numerous tissues by regulating the activity of the Gli family of transcription factors. Emerging evidence shows that Hh also functions as a chemoattractant in several processes through a noncanonical pathway independent of Gli-mediated transcription. How Hh-responsive cells execute transcriptional versus chemotactic responses is a key issue.