Characterization of a partial deletion of the factor VIII gene in a haemophiliac with inhibitor

Summary Genomic DNA from 49 Italian patients affected with severe haemophilia A was analysed by Southern blotting technique using a cDNA probe corresponding to exons 14–26 of coagulation factor VIII. No TaqI site mutation was observed in this sample. A partial deletion, eliminating exons 15–18 and spanning about 13 kb, was identified and characterized in one patient with anti-factor VIII antibodies.     

X-linked Charcot-Marie-Tooth disease

Summary Linkage analysis was performed on 41 subjects belonging to a large family with a recurrence of X-linked Charcot-Marie-Tooth disease (CMTX), by using 12 restriction fragment length polymorphism markers mapping in p11–q13. The results are in agreement with previous linkage data. Three new markers that are potentially useful for genetic analysis of CMTX families are described. A more precise estimate of the localization of the disease locus was attempted by multipoint linkage analysis.     

Status signalling and the ability to recognize dominants: an experiment with siskins (Carduelis spinus)

Because dominants usually exploit others and take a disproportionate share of the available resources, we should expect foragers to be choosy as to which individuals they join. Here we show that siskins (Carduelis spinus) discriminate between dominant and subordinate individuals on the first encounter without requiring cues such as overt aggression, and prefer to join subordinate individuals. Experimental enlargement or removal of the siskin black bib, which has been shown previously to be a reliable predictor of dominance, strongly suggests that dominance discrimination is based on the use of badges of status.