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HETEROPLASMY DEFENSE. "A third consequence of a uniparental system is that it guards against “heteroplasmy,” the presence of two or more different organelle genomes in the same organism. In a recent study, mice were artificially manipulated to be heteroplasmic for mitochondrial genomes, and they showed a number of developmental and cognitive defects; the investigators suggest that disparate OXPHOS subunits encoded by the two genomes might assemble into defective complexes." https://lnkd.in/ebVhXPf View in LinkedIn

ORGANELLE GENOME ELIMINATION. "This may serve to guard against “selfish” genomes that might otherwise infest and destroy the population, or even the species, with unregulated organelles. Again we encounter meiotic symmetry in that such “purging” functions are also a feature of meiosis.” https://lnkd.in/ebVhXPf View in LinkedIn

HAPLOID ORGANELLE SELECTION. "A second consequence of uniparental inheritance is that at each sexual generation, a uniform set of organelle genomes is exposed to natural selection in the “unmasked” haploid state, and a uniform set of organelle genomes is eliminated from the gene pool altogether." https://lnkd.in/ebVhXPf View in LinkedIn

ORGANELLE PLOIDY. "In most modern egg/sperm systems, the egg can have millions of organelle genomes, whereas sperm are either stripped of organelles or their organelle DNA is destroyed by the zygote. Therefore, if an “organelle ploidy” system played a role in establishing uniparental in isogamous organisms, this consideration is clearly irrelevant to modern anisogamous organisms." https://lnkd.in/ebVhXPf View in LinkedIn

ORGANELLE INHERITANCE. "This dilemma suggests a hypothesis regarding the origin of the near-universal pattern of organelle inheritance in modern sexual eukaryotes—the uniparental (UP) transmission of organelle genomes to meiotic products." http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn

QUESTION TO READERSHIP. A number of you have asked me if I would write a series of biologically-themed essays, similar to my posts here. They would be published online. Can you give me feedback if that would be of interest? View in LinkedIn

SELFING DEAD END. "Although selfing may be favored in the short term, due to the transmission advantage of selfing variants and ability of individuals to set seed in pollen-limited conditions, selfing species represent only 10–15% of angiosperms and predominant selfing is often viewed as an evolutionary dead end." https://lnkd.in/dX-FzGD View in LinkedIn

MULTIPLICATION. "The development of a sexual cycle would be expected to place such a control system in jeopardy. The fusion of gametes would generate diploid zygotes with twice the organelle-genome tally, and without some way to return to the “organelle-haploid” value, meiotic products would be “organelle-diploid” and then, in the next round, “organelle-tetraploid” and so on." https://lnkd.in/ebVhXPf View in LinkedIn

TRANSITION STATE. "The evolution of predominant self-fertilization (selfing) from cross-fertilization (outcrossing) is recognized as the most frequent evolutionary transition involving the reproductive systems of flowering plants." https://lnkd.in/dX-FzGD View in LinkedIn

SPECIES FIXATION. "Eukaryotes vary widely in numbers of mitochondria and chloroplasts per cell and in numbers of genomes per organelle, but in a given microorganism, or cell type in a multicellular organism, these values are maintained at constant levels." https://lnkd.in/ebVhXPf View in LinkedIn