Distribution of sister chromatid exchanges in different types of chromatin in the X chromosome ofMicrotus cabrerae

We used the X chromosomes ofMicrotus cabrerae as a model to analyze the distribution of sister chromatid exchanges (SCEs) on different types of chromatin, because of the marked heterogeneity of the heterochromatin in the entire short arm and a portion of the long arm of this chromosome. Computer-simulated distributions, according to an algorithm that makes it possible to modify the distribution on the basis of any possible hypothesis, were compared with real distributions by log-linear models. We found that the frequency of SCEs in different types of heterochromatin was higher than that expected for a random distribution, and located an SCE hot-spot at the junction between euchromatin and heterochromatin. The possible relationship between the distribution of SCEs and base composition or chromatin accessibility are discussed.     

Differential medium for the isolation and identification ofMycobacterium fortuitum complex

Summary A single medium efficiently selects for an identifiesMycobacterium fortuitum complex on the basis of bile tolerance and arylsulfatase activity.     

Gossypol. Synthesis and in vitro spermicidal activity of isomeric hemigossypol derivatives

Cellular and Molecular Life Sciences - Three isomeric hemigossypol derivatives (3, 4, 5) have been synthesized. Two of these derivatives (3, 4) and one synthetic intermediate (7) have been shown to...