Spermatogenesis and regulatory factors in the wall lizard Podarcis sicula

Spermatogenesis is an extraordinarily complex process, regulated by several factors, which leads to the differentiation of spermatogonia into spermatozoa. Among vertebrates, several reports have been focused on the lizard Podarcis sicula, a seasonal breeder and a good model for the study of reproductive processes. The goal of this review is to resume all the available data about systemic and above all local control factors involved in the control of P. sicula testicular activity. During the seasonal reproductive cycle, the variation of the expression levels of these factors determines significant variations that induce the activation or blocking of spermatogenesis. The data supplied in this review, in addition to analyze the current literature regarding the main actors of Podarcis sicula spermatogenesis, will hopefully provide a basic model that can be used for further studies on the intratesticular interaction between molecular factors that control spermatogenesis.

Biosynthesis of thromboxane by snake (Elaphe obsoleta) erythrocytes and the requirement of eicosanoid production for blood clotting

Lower vertebrates provide important insights into the evolution of eicosanoid synthesis and function. Whole snake blood, purified nucleated erythrocytes, and isolated leukocytes activated by clotting or A23187 produced thromboxane, PGE2, and 5-lipoxygenase products. Indomethacin's complete inhibition of clotting suggests eicosanoids produced by these cells are important in snake blood hemostasis.