Ameloblastic odontoma in a Sprague-Dawley rat

A spontaneously arising ameloblastic odontoma of the mandible is reported in in a 2-years old female Sprague-Dawley-rat. The morphological characteristics of the tumor are described as well as discussed in consideration of its histogenesis and differential diagnoses.     

Chemistry and biology of novel amine fungicides: Attempts to improve the antifungal activity of fenpropimorph

In spite of considerable efforts by many workers, there has been a lack of progress in the area of amine fungicides since fenpropimorph. Random synthesis of a large variety of different amine compounds, as well as intelligent structural modification of the lead structure fenpropimorph (well over 15 000 amines have been screened at BASF alone) have not led to a new market product so far. Further work has been focused on the reported mode of action of fenpropimorph, notably on the inhibition of the sterol Δ¹⁴-reductase. Although some doubt has to be cast on the hypothesis that fenpropimorph behaves as a sterol mimic, the concept of ‘high energy intermediate’ inhibitors has been employed successfully. Rational drug design of azasterol mimics has led to a number of very potent inhibitors of the sterol Δ¹⁴-reductase which also displayed high fungicidal activity in the greenhouse. Although many of these compounds are more powerful reductase inhibitors than fenpropimorph, under field conditions none showed significant advantages over this established fungicide. Most likely, fenpropimorph already exhibits the maximum fungicidal activity which can be attained by blocking the sterol Δ¹⁴-reductase. This would mean that, with the development of the ‘second generation’ amine fungicide fenpropimorph, this class of compounds has already virtually been optimized.     

A comparison of methods to estimate genomic relationships using pedigree and markers in livestock populations

Accurate prediction of breeding values depends on capturing the variability in genome sharing of relatives with the same pedigree relationship. Here, we compare two approaches to set up genomic relationship matrices for precision of genomic relationships (GR) and accuracy of estimated breeding values (GEBV). Real and simulated data (pigs, 60k SNP) were analysed, and GR were estimated using two approaches: (i) identity by state, corrected with either the observed ( G _{VR ‐O} ) or the base population ( G _{VR ‐B} ) allele frequencies and (ii) identity by descent using linkage analysis ( G _{IBD ‐L} ). Estimators were evaluated for precision and empirical bias with respect to true pedigree IBD GR. All three estimators had very low bias. G _{IBD ‐L} displayed the lowest sampling error and the highest correlation with true genome‐shared values. G _{VR ‐B} approximated G _{IBD ‐L} 's correlation and had lower error than G _{VR ‐O} . Accuracy of GEBV for selection candidates was significantly higher when G _{IBD ‐L} was used and identical between G _{VR ‐O} and G _{VR ‐B} . In real data, G _{IBD ‐L} 's sampling standard deviation was the closest to the theoretical value for each pedigree relationship. Use of pedigree to calculate GR improved the precision of estimates and the accuracy of GEBV.