Gene Polymorphisms are Associated with Eggshell Ultrastructure Organization in Hens

<div><p>ABSTRACT Background: Eggshell ultrastructure organization, including effective layer thickness, mammillary layer thickness, and average size of mammillary cones, is important for breeding and significantly influences eggshell mechanical properties. Several matrix proteins were known to be important in eggshell formation. However, the proteins and variations that determine eggshell ultrastructure organization are not known. Results: In this study, 17 single-nucleotide polymorphisms of three major genes in a hen population using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Five single-nucleotide polymorphisms with a very low minor allele frequency (< 1%) were excluded from further analysis. The remaining 12 single-nucleotide polymorphisms in Hardy-Weinberg equilibrium were used for analysis of associations with eggshell ultrastructure organization. Associations were found for (i) ovocleidin-116 with effective layer thickness (EFF), mammillary layer thickness (MAM), and average size of mammillary cones (SMAM); (ii) ovalbumin with eggshell thickness (ESH), effective layer thickness, and density of the mammillary cone (DMAM); and (iii) calmodulin1 with density of the mammillary cone. Conclusions: The single-nucleotide polymorphisms identified in the present study may be used as potential markers to improve eggshell quality.</p></div

Iron ethylene polymerization catalysts incorporating trifluoromethoxy functionality: Effects on PE molecular weight and productivity

The capacity to broaden the range of molecular weights displayed by polyolefinic materials is an important factor to be considered in the design of polymerization catalysts. Herein, the 2,6-dibenzhydryl-4-trifluoromethoxy modified bis(imino)pyridyl-ferrous chlorides, [2-[CMeN{2,6-{(C6H5)2CH}2-4-(F3CO)C6H2}]-6-(CMeNAr)C5H3N]FeCl2 [Ar = 2,6-Me2C6H3 Fe1, 2,6-Et2C6H3 Fe2, 2,6-i-Pr2C6H3 Fe3, 2,4,6-Me3C6H2 Fe4, 2,6-Et2-4-MeC6H2 Fe5], are used as precatalysts in the solution polymerization of ethylene. On the activation with either MAO or MMAO, all complexes displayed high productivity [up to 18.4 × 106 g (PE) mol-1 (Fe) h-1 for Fe5/MAO], generating highly linear polyethylenes with a wide range of molecular weights (Mw range: 0.85 × 103 to 8.80 × 105 g mol-1). Notably, higher activity was achieved in hexane than in toluene under MAO activation, while the opposite trend was seen with MMAO, highlighting the key role played by solvent in the polymerization process. By comparison with structurally related iron catalysts, the presence of the electron withdrawing para-trifluoromethoxy group has the effect of increasing the molecular weight of the polyethylene. In addition to the polymerization studies, full synthetic and characterization details are presented for Fe1-Fe5 including the X-ray structures of Fe1 and Fe2