Biomaterial Database

Doubly Uniparental Inheritance of mtDNA: An Unappreciated Defiance of a General Rule. 2019

Eleftherios Zouros, and George C Rodakis

Department of Biology, University of Crete, Heraklion, Greece. zouros@biol.uoc.gr.

We recount the basic observations about doubly uniparental inheritance (DUI) of mtDNA in bivalvian mollusks with an emphasis on those that were obtained from work in Mytilus and appeared after the review by Zouros (Evol Biol 40:1-31, 2013). Using this information, we present a new model about DUI that is a revised version of previously suggested models. The model can be summarized as follows. A Mytilus female either provides its eggs with the "masculinizing" factor S and the "sperm mitochondria binding" factor Z, or it does not. This property of the female is determined by two nuclear genes, S and Z, that are always in the on/on or the off/off phase. In fertilized eggs without factors S and Z the embryo develops into a female and the sperm mitochondria are randomly dispersed among cells following development. In fertilized eggs with factors S and Z, the first factor causes the cell to become eventually sperm and the second causes the sperm mitochondria to aggregate and anchor to the nuclear membrane by binding to a specific motif of the sperm-derived mtDNA. Factors S and Z are continuously co-synthesized and co-localized in the cell line from the egg to the sperm. The sperm mitochondria of the aggregate escape the mechanism that eliminates the cell's mitochondria before the formation of the sperm. The rescued mitochondria are subsequently packed into five mega-mitochondria in the sperm and are delivered in the egg.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D008957	Models, Genetic	Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Genetic Models,Genetic Model,Model, Genetic
D009687	Nuclear Proteins	Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.	Nucleolar Protein,Nucleolar Proteins,Nuclear Protein,Protein, Nuclear,Protein, Nucleolar,Proteins, Nuclear,Proteins, Nucleolar
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D004272	DNA, Mitochondrial	Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.	Mitochondrial DNA,mtDNA
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013094	Spermatozoa	Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.	Sperm,Spermatozoon,X-Bearing Sperm,X-Chromosome-Bearing Sperm,Y-Bearing Sperm,Y-Chromosome-Bearing Sperm,Sperm, X-Bearing,Sperm, X-Chromosome-Bearing,Sperm, Y-Bearing,Sperm, Y-Chromosome-Bearing,Sperms, X-Bearing,Sperms, X-Chromosome-Bearing,Sperms, Y-Bearing,Sperms, Y-Chromosome-Bearing,X Bearing Sperm,X Chromosome Bearing Sperm,X-Bearing Sperms,X-Chromosome-Bearing Sperms,Y Bearing Sperm,Y Chromosome Bearing Sperm,Y-Bearing Sperms,Y-Chromosome-Bearing Sperms
D015053	Zygote	The fertilized OVUM resulting from the fusion of a male and a female gamete.	Fertilized Ovum,Ovum, Fertilized,Fertilized Egg,Egg, Fertilized,Eggs, Fertilized,Fertilized Eggs,Zygotes