-The Texas Platycynorta transversalis is regarded as a junior synonym of V . sayi. Karyotypes of male and female V. sayi from central Texas reveal 2n = 78. This number is almost twice that previously reported for any other harvestman. The male reproductive system of V. sayi is described and illustrated. Natural history data are provided for egg laying and developmental times. The supercooling p...

Paper presents the first description of the so far unknown sexual generation of Pterocomma tremulae (Aphididae, Aphidinae): oviparous female and alate male. It also provides detailed description of the male reproductive system. Discussion focuses on comparative analysis of male reproductive system with other aphid groups and possible importance of its structure in resolving phylogenetic interre...

Adipose tissue is one of the major endocrine gland. More recently, local production of steroids in adipocytes differentiated from mouse 3T3-L1 cell-line was reported. We hypothesized that rat adipocytes have steroidogenic machinery and the expression patterns of the components might be differentially regulated, depending on the distribution and sex. To verify this hypothesis, we collected the a...

Male infertility is directly or indirectly responsible for 60% of cases involving reproductive-age couples with fertility-related issues. Nevertheless, the evaluation of male infertility is often underestimated or postponed. A coordinated evaluation of the infertile male using standardized procedures improves both diagnostic precision and the results of subsequent management in terms of effecti...

Life history theory posits that organisms face a trade-off between current and future reproductive attempts. The physiological mechanisms mediating such trade-offs are still largely unknown, but glucocorticoid hormones are likely candidates as elevated, post-stress glucocorticoid levels have been shown to suppress both reproductive physiology and reproductive behavior. Aged individuals have a d...

Numerous factors influence male fertility. Among these factors is oxidative stress (OS), which has elicited an enormous interest in researchers in recent period. Reactive oxygen species (ROS) are continuously produced by various metabolic and physiologic processes. OS occurs when the delicate balance between the production of ROS and the inherent antioxidant capacity of the organism is distorte...

A great deal of new information has arisen in the recent years concerning inhibin physiology and clinical relevance in reproductive medicine. It is now recognized that the two inhibin isoforms, named inhibin A and inhibin B, are produced by the gonads in the course of gamete maturation and in women have a different pattern of secretion throughout the menstrual cycle. Since inhibins are also pro...

Mammalian spermatozoa are unique cells in many ways, and the acquisition of their main function, i.e. fertilization capacity, is a multistep process starting in the male gonad and ending near the female egg for the few cells reaching this point. Owing to the unique character of this cell, the molecular pathways necessary to achieve its maturation also show some specific characteristics. One of ...