All experiments were conducted in accordance with the National Institute of Health Guidelines for Care and Use of Laboratory Animals and approved by the Institutional Animal Care Committee. Adult male ...

cyclic AMP and cyclic GMP are universal second messengers and are sensed by receptor proteins that contain cyclic nucleotide binding (CNB) domains. In mammal, CNB domains are found in protein kinase A ...

PNAS is the world's most-cited multidisciplinary scientific serial. It publishes high-impact research reports, commentaries, perspectives, reviews, colloquium papers, and actions of the Academy. In ...

Infertility affects about one in six couples, and male factors account for roughly half of all cases-often because sperm ...