Publications by authors named "A Bertha Koopmanschap"

With uniparental inheritance of mitochondria, there seems little reason for homologous recombination in mitochondria, but the machinery for mitochondrial recombination is quite well-conserved in many eukaryote species. In fungi and yeasts heteroplasmons may be formed when strains fuse and transfer of organelles takes place, making it possible to study mitochondrial recombination when introduced mitochondria contain different markers. A survey of wild-type isolates from a local population of the filamentous fungus Podospora anserina for the presence of seven optional mitochondrial introns indicated that mitochondrial recombination does take place in nature.

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Calorie restriction (CR) is a regimen of reduced food intake that, although the underlying mechanism is unknown, in many organisms leads to life span extension. Podospora anserina is one of the few known ageing filamentous fungi and the ageing process and concomitant degeneration of mitochondria have been well-studied. CR in P.

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Although most fungi appear to be immortal, some show systemic senescence within a distinct time frame. Podospora anserina for example shows an irreversible growth arrest within weeks of culturing associated with a destabilization of the mitochondrial genome. Here, we show that calorie restriction (CR), a regimen of under-nutrition without malnutrition, increases not only life span but also forestalls the aging-related decline in fertility.

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Metamorphosis and reproduction in insects are controlled by juvenile hormone (JH). One of the factors, which regulate the JH titer in the hemolymph, is the activity of juvenile hormone esterase (JHE). JHE from the Colorado potato beetle, Leptinotarsa decemlineata, consists of two 57kDa subunits.

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Juvenile hormone esterase (JHE) activity in the haemolymph of the Colorado potato beetle is necessary to initiate pupation in larvae as well as diapause in adults. The enzyme appears in the haemolymph as a dimer consisting of two 57 kDa subunits. The sequence of an encoding cDNA, JHE.

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