Organelle Genetics

Through the compartmentalization of function and genetic material, mitochondria and chloroplasts represent a fundamental level of subcellular complexity in eukaryotes. Although these organelles carry genes that are critical for their function, they are also completely dependent on nuclear gene products. Understanding the coordination and cooperation between the spatially separated genetic compartments of the eukaryotic cell is a common goal of the organelle genetics research groups at MSU.

By exploiting the detailed gene maps and complete genome sequences that are available from several representatives of both organelle types, genes have been located on the genomes of the related organelles from other species. In addition, sequence data from nuclear cDNAs and cloned genes that encode products destined for the organelles have been consulted to enable the identification and isolation of orthologous genes. Nuclear genes that govern the integrity and maintenance of organelles and their genomes are being studied in the fruit fly Drosophila, the filamentous fungus Neurospora, the unicellular green alga, Chlamydomonas, and the dicotyledonous plant Arabidopsis. In Drosophila, higher plants, fungi and trypanosomes, controls of gene expression are being examined through the assessment of RNA transcriptional and translational regulation, processing of primary transcripts, and RNA editing. Other topics of inquiry include the transport of proteins and signal molecules into organelles, communication for coordinate gene expression between organelle and nuclear genomes, and regulatory controls of the alternative oxidase pathway of the mitochondrion.