Asynchronously growing cells of a M3-1 Chinese hamster line were ultraviolet (UV) irradiated (lambda = 254 nm) with UV fluences up to 7.5 J/m(2). After irradiation cells were incubated with or without 2 mM caffeine for 20 hr, then mitotic cells were selected by mechanical shaking. Their chromosomes were isolated, stained with Hoechst 33258 and chromomycin A3, and measured flow cytometrically. W...

Allosteric regulation of protein function is a critical component of metabolic control. Its importance is underpinned by the diversity of mechanisms and its presence in all three domains of life. The first enzyme of the aromatic amino acid biosynthesis, 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase, shows remarkable variation in allosteric response and machinery, and both contemporary re...

The aim of this report has been evaluating protamine content and DNA integrity of two patients with globozoospermia undergoing Intra Cytoplasmic Sperm Injection (ICSI). Semen analysis was carried out according to WHO criteria. Protamine deficiency and DNA fragmentation was assessed using Chromomycin A3 and sperm chromatin dispersion assay respectively. ICSI and chemical activation were carried ...