Seminal fluid is an important part of the ejaculate of internally fertilizing animals. This fluid contains substances that nourish and activate sperm for successful fertilization. Additionally, it contains components that influence female physiology to further enhance fertilization success of the sperm donor, possibly beyond the recipient's optimum. Although evidence for such substances abounds...

A steady-state fluorescence polarization technique, using the membrane probe 1,6-diphenyl-1,3,5-hexatriene (DPH), showed that separately detectable transitions occurred in the regions of 17, 26 and 36 degrees C in isolated preparations of ram sperm plasma membrane. An independent technique based on the temperature-related behaviour of calcium- and magnesium-activated ATPase detected a single ph...

The Physiology and Endocrinology Symposium titled “Sperm-Oviduct Interactions in Livestock and Poultry” was held at the joint annual meeting of the American Society of Animal Science, American Dairy Science Association, Poultry Science Association, Asociación Mexicana de Producción Animal, and Canadian Society of Animal Science, with partial sponsorship by the EAAP (European Federation of Anima...

BACKGROUND The importance of estrogen in regulation of fluid absorption and sperm maturation in the rodent epididymis has been established from studies on estrogen receptor-alpha knockout mice. However, functional studies on the role of estrogen in primate epididymis have been few. The main objective of this study was therefore to extend these observations and systematically analyze the presenc...

Male infertility due to abnormal spermatozoa has been reported in both animals and humans, but its pathogenic causes, including genetic abnormalities, remain largely unknown. On the other hand, contraceptive options for men are limited, and a specific, reversible and safe method of male contraception has been a long-standing quest in medicine. Some progress has recently been made in exploring t...

What is sperm storage? Sperm storage is most commonly defined as the maintenance of sperm inside a female’s reproductive tract for an extended period of time. Because the fate of sperm post-copulation is important for understanding sexual selection, sperm storage is a particularly interesting characteristic that may have drastic impacts on the operation of post-copulatory sexual selection. Sper...

T hirty years ago, on July 25, Steptoe and Edwards reported the birth of Louise Joy Brown, the first successful ‘‘Test-Tube’’ baby (1). This achievement followed a lack of success of in vitro fertilization experiments for almost 80 years since the first attempts in 1878. These early failures were due mainly to a lack of comprehension of sperm physiology. In the early 1950s, Chang (2) and Austin...

--To assess natural variation in ejaculate quality of male Dark-eyed Juncos (Junco hyemalis), as well as to measure any effect of experimental treatment with testosterone (T), we used cloacal massage to collect sperm samples from captive (1993) and free-ranging (1994, 1995) populations. We made three measurements of ejaculate quality in males, approximately half of which had been treated with T...

STUDY QUESTION Does fibronectin (Fn) stimulate the sperm capacitation process in humans? SUMMARY ANSWER Fibronectin stimulates human sperm capacitation. WHAT IS KNOWN ALREADY Capacitation is a process that occurs in the oviduct. It has been suggested that some molecules present in the oviductal fluid and cells as well as proteins present in the cumulus oophorus could be involved in the modu...

Background: Zinc in human semen seems to play an important role in the physiology of spermatozoa. Zinc deficiency leads to gonadal dysfunction, decreases testicular weight, and causes shrinkage of seminiferous tubules. The adult human body contains 1-3 g of zinc, about 0.1% of which is replenished daily. Excessively high amounts of zinc has been reported in human seminal plasma by many authors,...