Nuclear genome

Transcriptional inhibitors could be used simultaneously. Rifampicin blocks chloroplast and mitocondrian RNA synthesis [23, 24], while tagetitoxin is a very specific inhibitor of chloroplast RNA polymerase [25]. Treatment with these antibiotics does not inhibit Rubisco SSU synthesis since the promoter is part of the nuclear genome, while the cytosolic ribosomes are not affected by streptomycin. Therefore SSU promoters can be used to drive transgene expression and facilitate the accumulation of recombinant proteins. Expressed proteins are targeted to a suitable cellular compartment, such as the cytoplasm, apoplastic space or chloroplast, depending on the nature of the protein. 

Defects of complex II. These have not been fully characterized in the few reported patients, and the diagnosis has often been based solely on a decrease of succinate-cytochrome c reductase activity (Fig. 42-3). However, partial complex II deficiency was documented in muscle and cultured fibroblasts from two sisters with clinical and neuroradiological evidence of Leigh s syndrome, and molecular genetic analysis showed that both patients were homozygous for a point mutation in the flavoprotein subunit of the complex [17]. This was the first documentation of a molecular defect in the nuclear genome associated with a respiratory chain disorder. 

Doolittle, W. F. (1998). You are what you eat a gene transfer ratchet could account for bacterial genes in eukaryotic nuclear genomes. Trends Genet. 14, 307—311. 

Figure 1. Control of mitochondrial biogenesis by the nuclear genome. Most mitochondrial proteins, including cytochrome c, are nuclear gene products which are subsequently imported into mitochondria. Similarly, most enzymes involved in synthesis of mitochondrial phosphoplipids are encoded in the nuclear genome. Being located in the endoplasmatic reticulum, they synthesize phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), phosphatidylglycerol (PG) and phosphatidylinositol (Ptdins). The phospholipids are transferred to the outer membrane. The imported lipids then move into the inner membrane at contact sites. Mitochondria then diversify phospholipids. They decarboxylate phosphatidylserine to phosphatidylethanolamine (PtdEtN), but the main reaction is the conversion of imported phosphatidylglycerol to cardiolipin (CL). Cardiolipins localize mainly in the outer leaflet of the inner membrane.

We have the 120 million base pair nuclear genome for Chlamydomonas, a unicellular, photosynthetic green alga. This organism diverged from land plants more than one billion years ago. It is a ciliated organism, an innovation inherited from a progenitor of animals and plants, subsequently lost in land plants. 

Brain, muscle, and kidney cells, for example, all possess a few hundred or a few thousand mitochondria per cell. The human egg cell is remarkable in that it contains about 100,000 mitochondria. A sperm cell, in contrast, contains fewer than 100. New mitochondria are made as cells divide. The synthesis of new mitochondria requires that the proteins coded for by the nuclear genome and those coded for by the mitochondrial genome be mutually compatible to ensure optimal mitochondrial function. Since we can experience mutations in both nuclear and mitochondrial DNA, leading to alterations in mitochondrial proteins, long-term compatibility... 

The cultivated potato and many of its relatives are amenable to eell and tissue culture procedures, ineluding protoplast isolation and fusion. Somatic cell fusions have frequently been used to eombine the genomes of Solarium speeies that are sexually ineompatible because of pollen-stylar interactions or mismatched EBN numbers. Somatic fusion circumvents sexual reproduetion and results in novel eombinations of not only nuclear genomes, but also cytoplasmic genomes (Trabelsi et al., 2005 Bidani et al., 2007 Lovene et al., 2007). However, recalcitrant genotypes... 

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