The acrosomal protein SP-10 (Acrv1) is an ideal marker for staging of the cycle of seminiferous epithelium in the mouse.

The study of spermatogenesis requires accurate identification of the stages of the cycle of the seminiferous epithelium. A stage refers to the unique association of germ cell types at a particular phase of development, as seen in a cross-sectioned seminiferous tubule. Stage-identification, however, is a daunting task.

JunB mediates basal- and TGFβ1-induced smooth muscle cell contractility.

Smooth muscle contraction is a dynamic process driven by acto-myosin interactions that are controlled by multiple regulatory proteins. Our studies have shown that members of the AP-1 transcription factor family control discrete behaviors of smooth muscle cells (SMC) such as growth, migration and fibrosis. However, the role of AP-1 in regulation of smooth muscle contractility is incompletely understood.

FosB regulates stretch-induced expression of extracellular matrix proteins in smooth muscle.

Fibroproliferative remodeling in smooth muscle-rich hollow organs is associated with aberrant extracellular matrix (ECM) production. Although mechanical stimuli regulate ECM protein expression, the transcriptional mediators of this process remain poorly defined. Previously, we implicated AP-1 as a mediator of smooth muscle cell (SMC) mechanotransduction; however, its role in stretch-induced ECM regulation has not been explored.

An Akt- and Fra-1-dependent pathway mediates platelet-derived growth factor-induced expression of thrombomodulin, a novel regulator of smooth muscle cell migration.

Overdistension of hollow organs evokes pathological changes characterized by smooth muscle remodeling. Mechanical stimuli induce smooth muscle cell (SMC) growth through acute activation of signaling cascades and by increased expression of soluble mitogens. Physical forces have also been implicated in ligand-independent activation of receptor tyrosine kinases, including the platelet-derived growth factor (PDGF) receptor, although the extent to which this occurs in intact tissue is unknown.

Identification of novel immunodominant epididymal sperm proteins using combinatorial approach.

Functionally immature spermatozoa leave the testis mature during epididymal transit. This process of maturation involves either addition of new proteins or modification of existing proteins onto the sperm domains that are responsible for domain-specific functions. Epididymal proteins are preferred targets for immunocontraception.

Role of an insulator in testis-specific gene transcription.

Testis-specific promoters are unique in that relatively short proximal promoters of several genes have been shown to be capable of directing tissue- and cell-type-specific expression in transgenic mice. How such small promoter fragments perform the dual functions of maintaining a silenced state in somatic tissues and activating gene expression in the correct germ-cell type in testis remains poorly understood. Studies from our laboratory using the round spermatid-specific SP-10 gene as an experimental model have provided some insights into the mechanisms involved.

NF45 and NF90 in murine seminiferous epithelium: potential role in SP-10 gene transcription.

Identification of transcription factors involved in the progression of spermatogenic cell differentiation is important for understanding the molecular mechanisms controlling spermatogenesis. To this end, we utilized the mouse SP-10 gene encoding a conserved acrosomal protein as an experimental model. Promoter analysis in transgenic mice had previously shown that the -186/-91 region of the SP-10 promoter was critical for spermatid-specific expression.

Monoclonal antibodies to epididymis-specific proteins using mice rendered immune tolerant to testicular proteins.

Monoclonal antibodies (mabs) have been used as a powerful tool for identification of newer sperm proteins. However, conventional hybridoma technology rarely provides chance to obtain mabs to epididymal proteins. To increase this chance, we have used an alternate method of neonatal tolerization.