A hybrid zone between two subspecies of Chorthippus parallelus. X-chromosome variation through a contact zone

Two grasshopper subspecies, Chorthippus parallelus parallelus (Cpp) and Chorthippus parallelus erythropus (Cpe), meet along the Pyrenees where they hybridize and produce a hybrid zone. A contact zone located in the Col de Portalet has been analyzed for the distribution of chromosome markers on the sex (X) chromosome in pure and hybrid populations. C-banding allowed us to distinguish both pure subspecific forms and recombinant forms, and to demonstrate their different frequencies through the contact zone. Interestingly, the distal C-band (P) on the X chromosome that characterizes Cpp individuals occurs at very high frequency through the zone and then drops sharply, close to where pure Cpe populations are found. A novel interstitial C-band (H) has been found, probably derived from that characterizing Cpe individuals (E). This marker band is only present in hybrid populations. These data are discussed in the light of the dynamics of the hybrid zone.     

Genetically encoded FRET-pair on the basis of terbium-binding peptide and red fluorescent protein

The genetically encoded FRET-pair was developed on the basis of terbium-binding peptide and red fluorescent protein DsRed2. To study fluorescence resonance energy transfer within the FRET-pair, the engineered construction was obtained, where sequences of terbium-binding peptide and red fluorescent protein DsRed2 were fused in single reading frame. The expression of this construction in strain E. coli BL21(DE3) was studied and conditions of synthesis, isolation, and purification of recombinant protein were optimized. The hydrodynamic radius of hybrid protein was determined by the method of dynamic diffusion. Energy transfer between sensitized terbium and red fluorescent protein was confirmed by the methods of fluorescence spectroscopy. The obtained FRET-pair may be used both for studies in vitro and as reporters in living cells.     

Epicardial Ablation For Ventricular Tachycardia

Epicardial ablation has lately become a necessary tool to approach some ventricular tachycardias in different types of cardiomyopathy. Its diffusion is now limited to a few high volume centers not because of the difficulty of the pericardial puncture but since it requires high competence not only in the VT ablation field but also in knowing and recognizing the possible complications each of which require a careful treatment.This article will review the state of the art of epicardial ablation with special attention to the procedural aspects and to the possible selection criteria of the patients.