Search results for "genetics [Bladder Exstrophy]"

Development and localization of microsatellite markers for the sibling species Chironomus riparius and Chironomus piger (Diptera: Chironomidae)

2006

Five variable microsatellite loci are reported for the nonbiting midge species Chironomus riparius and Chironomus piger. All loci show considerable intraspecific variation and species-specific alleles, which allow to discriminate among the two closely related species and their interspecific hybrids, and to estimate genetic diversity within and between populations. Additionally, the loci were localized on C. riparius polytene chromosomes to verify their single copy status and investigate possible chromosomal linkage. The described markers are used in different studies with regard to population and ecological genetics and evolutionary ecotoxicology of Chironomus.

Chlorophyll-Protein Complexes of Chlorella fusca

1980

Chlorophyll-protein complexes from thylakoids of the normal type and two mutants of Chlorella fusca were separated using sodium dodecyl sulfate acrylamide gel electrophoresis (PAGE). The properties of the chlorophyll-protein complexes of the three strains of Chlorella were compared. Standard curves were set up for the characterization of the chlorophyll-proteins. In every electrophoretic separation of chlorophyll-protein complexes, a certain amount of pigment is separated from the protein. We tried to keep that amount as low as possible by mild solubiliza­tion and by working in low temperature. Under these conditions, we obtained several new chlorophyll-proteins in addition to the P-700-chl…

Studies of Components of the Thylakoid Membrane of Undamaged and Damaged Spruce Trees at Different Mountain Sites

1993

During a five-year period, components of the thylakoid membrane in needles of the second generation of undamaged and damaged trees of Norway spruce were studied at three different mountain sites in West Germany. Visible signs of damage at these sites are a yellowing of the light-exposed sides of the needles as well as the loss of needles. The goal of this study was to determine damage-induced alterations in composition and physiological reactions of the thylakoid membranes in spruce needles. In order to meet this purpose, contents of chlorophyll a and b, electron transport rate of photosystem II, contents of the D 1 protein, cytochrome f, as well as P-700 were measured. The chlorophyll cont…

Nanochlorum eucaryotum: a Very Reduced Coccoid Species of Marine Chlorophyceae

1982

Nanochlorum eucaryotum was isolated from a sea water aquarium housing different sponge species, cucumarias, small crustaceans and annelids. This bright green marine alga differs from all other known coccoid species. Its most prominent features are its very small cell size (1.5 pm) and its reduced cellular organization. Its cell contains one nucleus, one chloroplast, one mitochondrium and small vacuoles. Sometimes a Golgi apparatus can be seen. No other subcellular features have been observed. The cell wall is thin and smooth and does not contain any material of high electron density; only dividing cells show a rougher surface. The cells split into two daughter cells. No sexual reproduction …

Effect of Phosphinothricin (Glufosinate) on Photosynthesis and Photorespiration

1990

Phosphinothricin (PPT) causes a rapid inhibition of photosynthesis under atmospheric conditions (400 ppm CO2, 21% O2). However, under conditions (1000 ppm CO2, 2% O2) under which photorespiration cannot occur, there is no or only a very low rate of photosynthesis inhibition by phosphinothricin. Under both conditions, a strong NH4 +-accumulation is apparent caused through the inhibition of glutamine synthetase by phosphinothricin. This indicates, that NH4 +-accumulation cannot be the primary cause for photosynthesis inhibition by phosphinothricin, but a process in connexion with photorespiration plays a central role. Through the lack of amino donors, the transamination of glyoxylate to glyci…

IM30 triggers membrane fusion in cyanobacteria and chloroplasts

2015

The thylakoid membrane of chloroplasts and cyanobacteria is a unique internal membrane system harbouring the complexes of the photosynthetic electron transfer chain. Despite their apparent importance, little is known about the biogenesis and maintenance of thylakoid membranes. Although membrane fusion events are essential for the formation of thylakoid membranes, proteins involved in membrane fusion have yet to be identified in photosynthetic cells or organelles. Here we show that IM30, a conserved chloroplast and cyanobacterial protein of approximately 30 kDa binds as an oligomeric ring in a well-defined geometry specifically to membranes containing anionic lipids. Triggered by Mg2+, membr…

CLINICAL AND EXPERIMENTAL STUDIES WITH CHLORPROPAMIDE IN DIABETES MELLITUS, IN NORMAL INDIVIDUALS, AND IN NONDIABETICS WITH HEPATIC DISEASE

1959

Decreased response to acetylcholine during aging of Aplysia neuron R15

2013

How aging affects the communication between neurons is poorly understood. To address this question, we have studied the electrophysiological properties of identified neuron R15 of the marine mollusk Aplysia californica . R15 is a bursting neuron in the abdominal ganglia of the central nervous system and is implicated in reproduction, water balance, and heart function. Exposure to acetylcholine (ACh) causes an increase in R15 burst firing. Whole-cell recordings of R15 in the intact ganglia dissected from mature and old Aplysia showed specific changes in burst firing and properties of action potentials induced by ACh. We found that while there were no significant changes in resting membrane p…

EphrinB2 controls vessel pruning through STAT1-JNK3 signalling

2014

Angiogenesis produces primitive vascular networks that need pruning to yield hierarchically organized and functional vessels. Despite the critical importance of vessel pruning to vessel patterning and function, the mechanisms regulating this process are not clear. Here we show that EphrinB2, a well-known player in angiogenesis, is an essential regulator of endothelial cell death and vessel pruning. This regulation depends upon phosphotyrosine-EphrinB2 signalling repressing c-jun N-terminal kinase 3 activity via STAT1. JNK3 activation causes endothelial cell death. In the absence of JNK3, hyaloid vessel physiological pruning is impaired, associated with abnormal persistence of hyaloid vessel…

The Separation of High and Low Molecular Weight RNA by Precipitation with N-Cetyl- N,N,N-trimethyl-ammoniumbromide

1977

Abstract RNA with a sedimentation constant of 28S and 18S can easily be separated from 4S and 5S RNA. The method depends on the different solubulities of nucleic acids in solutions of the cationic detergent N-cetyl-N,N,N-trimethyl-ammoniumbromide at various ionic strengths. The separation can be achieved with high efficiency in one step.