User:Charitha2023k/Nuclear gene

A nuclear gene is a gene that has its DNA nucleotide sequence physically situated within the cell nucleus of a eukaryotic organism. This term is employed to differentiate nuclear genes, which are located in the cell nucleus, from genes that are found in mitochondria or chloroplasts. The vast majority of genes in eukaryotes are nuclear.

Endosymbiotic organelle interactions
Furthermore, Mitochondria depend on nuclear genes for essential protein production as they cannot generate all necessary proteins independently.

Protein synthesis:
Most proteins in a cell are products of messenger RNA transcribed from nuclear genes, including those in organelles. These proteins are produced in the cytoplasm and then transported to the organelles. Genes in the nucleus are linearly arranged on chromosomes, serving as scaffolds for replication and gene expression regulation. They are usually under strict copy-number control, replicating once per cell cycle. Certain nuclear cells, like platelets, lack nuclear DNA and must source RNA elsewhere for protein production. With the human nuclear genome consisting of 3.3 billion DNA base pairs, one example of a nuclear gene is MDH1, the malate dehydrogenase 1 gene. MDH1 codes for the cytosolic isozyme involved in the malate-aspartate shuttle, a critical process in various metabolic pathways, such as the citric acid cycle. This gene plays a significant role in an organism's physiological functions. While non-nuclear genes may have functional roles, the interaction and coordination of nuclear genes with non-nuclear genes are fundamental.

Significance:
Low-copy nuclear genes in plants are valuable for improving phylogenetic reconstructions, especially when universal markers like Chloroplast DNA, or cpDNA and Nuclear ribosomal DNA, or nrDNA fall short. Challenges in using these genes include limited universal markers and the complexity of gene families. Nonetheless, they are essential for resolving close species relationships and understanding plant phylogenetic studies. While using low-copy nuclear genes requires additional lab work, advances in sequencing and cloning techniques have made it more accessible. Fast-evolving introns in these genes can offer crucial phylogenetic insights near species boundaries. This approach, along with the analysis of developmentally important genes, enhances the study of plant diversity and evolution.

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