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THE CONUNDRUM. “The evolution of sperm modification by Wolbachia poses an evolutionary puzzle—the trait is only expressed in males and yet symbionts in males are not passed on to the next generation. In randomly mating populations, it will be at best selectively neutral.” https://lnkd.in/dXjWp9f View in LinkedIn

COEVOLUTION. “As Wolbachia genomes often carry divergent cif homologs, the absence of recombination between these genes is compatible with recombination being constrained by selection. This can be explained by the coevolution of binding affinities between the proteins encoded by cifA and their cognate cifB gene.” https://lnkd.in/dXjWp9f View in LinkedIn

ROLE OF RECOMBINATION. “Whether recombination itself created these incompatibilities or whether crossing types arose due to sequence divergence following recombination is unknown. We found that recombination is frequent across the cif gene phylogeny, but it almost exclusively occurs between related syntenic cifA–cifB gene pairs within the same Type.” https://lnkd.in/dXjWp9f View in LinkedIn

RECOMBINATION. “Despite this, clear evidence of recombination has been observed among cif genes from wPip, which infects C. pipiens mosquitoes. wPip strains can carry multiple copies of Type I cif genes, and recombination between closely related paralogs correlates with different CI crossing types.” (CI = cytoplasmic incompatibility). https://lnkd.in/dXjWp9f View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and concludes this weekend on the evolutionary strategy of Wolbachia bacteria to control their host zygote survival by cytoplasmic compatability. This extreme strategy has made them a very successful parasite. View in LinkedIn

UNCORRELATED. “Interestingly, Lepage et al. (2017) found no significant association between the phylogenies of cif genes and genes found in the structural module of phages. Prophage regions often rearrange which likely explains this pattern.” https://lnkd.in/dXjWp9f View in LinkedIn

ASSISTANCE FROM OTHER PLAYERS. “Horizontal transfer of cif genes occurs frequently and sometimes over large phylogenetic distances, sometimes even crossing the bacterial genus boundaries. High rates of horizontal transfer likely result from the cif genes being associated with mobile genetic elements, such as WO prophage sequences, transposons, and plasmids.” https://lnkd.in/dXjWp9f View in LinkedIn

Old pots in Catalonia that get cracked are frequently mended by means of metal staples. View in LinkedIn

SURVIVAL STRATEGY. “The pervasive horizontal transfer of cif genes may allow them to evade inevitable extinction within symbiont lineages by escaping into a new symbiont population. This process is analogous to the evolution of transposable elements, which frequently go extinct within host species, but persist long term by jumping into new species.” https://lnkd.in/dXjWp9f View in LinkedIn