Month: September 2022

REMAINING QUESTIONS. “This may explain why, to our knowledge, there are no reports of strains from these supergroups inducing CI. However, divergent Type V cif genes are found in other Rickettsiales, and here their phenotypic effects are uncertain. Gillespie et al. (2018) proposed that cif homologs found in Rickettsia may induce other reproductive phenotypes.” (CI = cytoplasmic incompatibility). https://lnkd.in/dXjWp9f View in LinkedIn

EXAPTATION. “For instance, R. felis strain LSU-Lb, which carries Type V cif genes on its plasmid, infects a parthenogenetic insect. Accurate rooting of the cif gene tree together with functional characterization of these genes will be needed to confirm whether the ancestral function of these genes was to induce CI. However, the presence of a CI-inducing Wolbachia strain that has only Type V genes suggests that CI evolved very early in the evolution of cif genes.” (CI = cytoplasmic incompatibility). https://lnkd.in/dXjWp9f View in LinkedIn

EARLY OBSERVATIONS. “It has long been observed that crosses between insects carrying different Wolbachia strains are frequently incompatible, suggesting that modification and rescue factors must be matched to produce viable offspring.” https://lnkd.in/dXjWp9f View in LinkedIn

MOLECULAR EVOLUTION. “A possible molecular cause of this phenomenon comes from the observation that cifA and cifB bind each other, and so binding affinities may be greatest between coevolved genes. If this is the case, then there would be strong selection against recombination between the genes as this could generate symbionts that are unable to rescue crosses with infected females.” https://lnkd.in/dXjWp9f View in LinkedIn

FINE PRINT. “Furthermore, even if the symbiont retained the ability to rescue the cross, for example, if genes are swapped among paralogous pairs within the genome, the pair of genes might be eliminated in the long term if it generated self-incompatibility when transferred to a new genome.” https://lnkd.in/dXjWp9f View in LinkedIn

SO ENDS this first of two weekends on the cunning strategy of the bacteria Wolbachia which has enabled it to colonize half of the insect species in the world. The ability of symbionts and parasites to enact sophisticated strategies on their hosts makes one suspect that more than chance is at play, but when nature gambles at such high rates over geological time, even slim probabilities can become realities. It is a game of sheer numbers against the odds of chance. View in LinkedIn

LIKE GENETICS VS EMBRYOLOGY. “Synthetic biology presents a challenge to traditional accounts of biology: Whereas traditional biology emphasizes the evolvability, variability, and heterogeneity of living organisms, synthetic biology envisions a future of homogeneous, humanly engineered biological systems that may be combined in modular fashion.” https://lnkd.in/dhkrmJx View in LinkedIn

These seemingly fragile gems withstand storms, dirt, predators and pollution, and are tough enough to migrate long distances. View in LinkedIn

“PHYSICS is full of opposites. For every action, there’s a reaction; every positive charge has a negative; every magnetic north pole has a south pole. Matter’s opposite number is antimatter. And for black holes, meet white holes. Black holes are notorious objects that suck in everything around them. Famously, not even light can escape their awesome gravity. White holes, in contrast, blow out a constant stream of matter and light – so much so that nothing can enter them.” https://lnkd.in/djSRsBX View in LinkedIn

GEOMETRIC CONTORTIONS. “It is not surprising that energy flow does not follow such a geodesic through the transition from the black hole to the white hole, where the geometry is changing rapidly from collapse to expansion.” https://lnkd.in/dUKnus8 View in LinkedIn