A novel method for the measurement of elemental selenium produced by bacterial reduction of selenite.

The measurement of elemental selenium (Se(0)) is needed to assess the rate and magnitude of bacteria reduction of selenite or selenate. We have developed a spectrophotometric method for the measurement Se(0) that is rapid and can be employed to measure the quantity of Se(0) produced by bacterial cultures. This method employs the use of 1M Na(2)S to convert the insoluble elemental selenium to a red-brown solution and with this method there is a direct correlation between concentration of elemental selenium and the absorption at 500nm.

Roles of Src family kinase signaling during fertilization and the first cell cycle in the marine protostome worm Cerebratulus.

For eggs to generate a calcium response during fertilization, the sperm of many deuterostome animals must first activate a group of egg kinases, called Src family kinases (SFKs). However, whether SFK activation is also required for fertilization-induced calcium signals in eggs of protostomes remains unknown. Thus, in this study, unfertilized oocytes of the marine protostome worm Cerebratulus were treated with either PP2 to inhibit SFKs or with U73122 to block phospholipase C activity downstream of SFK.