User:Natoleon/Horizontal Gene Transfer

Article Draft
Horizontal gene transfer

the first .. so this article seems to be about the role of HGT in speciation. Even though it throws a wrench in things, it does not distort, or force us to significantly reconceptualize evolutionary processes, except for bacteria. In bacteria it seems like HGT, or LGT has played a much more significant role in speciation, I want to say, but that's not the right word. And second .. this article discusses the reduction of endosymbiont genomes, and how the host genome has parts horizontally transferred from the endosymbiont as well as past symbionts, deeper in the evolutionary history of the host. Genes in the host cells of the endosymbiont were found to upregulate their genes as a way to compensate for the endosymbionts deteriorated primary metabolic pathways.

And hey, since fungi would have this tendency within lichen - the the fungi would horizontally acquire some genes necessary for complex chemical pathways, surely? some of which are for secondary metabolites. And third .. a fungus that was horizontally transferred the genes necessary to make a family of proteins, that actually serves a protein-cutting purpose. fourth this article documents a case where HGT work the other way, from plant to bacteria, and from plant to fungi, and then continued HGT between bacteria and fungi. Talking about expansin genes which weakens cell walls, perhaps making them more prone to interspecies interaction.

HGT is particularly active in bacterial genomes around the production of secondary or specialized metabolites. This is clearly exhibited within certain groups of bacteria including P. aeruginosa and actinomycetales, an order of Actinomycetota. Polyketide synthase s (PKSs) and biosynthetic gene clusters provide modular organizations of associated genes making these bacteria well-adapted to acquire and discard helpful modular modifications via HGT. Certain areas of genes known as hotspots further increase the likelihood of horizontally transferred secondary metabolite-producing genes. The promiscuity of enzymes is a reoccurring theme in this particular theatre.

Numero ceese This article also highlights bacteria, this actinomycete genus Salinispora, and makes clear the significant role of HGT in the associated biosynthetic gene clusters which are well evolved for future HGT. Certain groups of bacteria have specially evolved to benefit from HGT

And this one has a very promising title, and it's recent. Enzyme promiscuity, referenceing the Fishbach paper as well, is a common theme in the horizontal transfer of genes involved in the production of secondary or specialized metabolites. Lest we forget this banger it explains that secondary metabolite genes are acquired and discarded by bacteria in their pursuit of fitness and most conducive genome. And in P. aeruginosa, part of the genome for secondary metabolite production is found within a genetic hotspot, inculcated in HGT. A phaseolotoxin gene cluster that is invovled in secondary metabolite production is also inculcated in this HGT affair. The article makes it clear that HGT has played a major in developing secondary metabolite abilities.

Article body
Horizontal gene transfer plays a significant and relatively poorly understood role in evolution. The evolution of secondary metabolite production is partly a product of horizontal gene transfer.

In Husnik et al. they explain how symbionts tend to reduce gene load, I would say. By relying a symbiont, a host and the other parties involved, have less genetic demand, the prerequisites for survival are lesser, and so their genes respond accordingly.

Interestingly, in this tripartite symbiosis, the host was the recipient of horizontally transferred genes from many endosymbionts, more than half a dozen, not longer present within the symbiosis.

The paper describes an endosymbiont of an endosymbiont of Planococcus cirtri(italicise). And they compare the middle symbiont's genome to the genome of the same 'species' lacking the final endosymbiont.

There is talk in the paper especially of the biosynthesis of peptidoclycans and essential amino acids.

Reviewing the nature article now. it seems from figure 1 that that endosymbionts' genes specialize in essential biological processes, being associated with a host's genome being more free to accommodate other genes. Not sure about this interpretation

Host tissues provide a rich source of metabolites the article says. Including and perhaps especially secondary metabolites?

These endosymbiont bacteria with tiny genomes maintain genes for replication, transcription, and translation. Genes related to protein folding and stability are also maintained. And that is all that is common across these greatly reduced bacterial genomes. Beyond this though, these endosymbionts also retain genes for provisioning nutrients to the host, including amino acid synthesis and informational processing - sounds like chemical ecology, maybe.

Genes most commonly lost by our organisms of interest include those for cell envelope biogenesis, regulation of gene expression, and DNA repair and recombination. But they are not necessarily transferred to the host.

Gene transfer to the host is another explanation of endosymbionts small genomes: most organellar RNA and proteins come from the host. But this is not likely common with insect symbionts.

These examples refute earlier ideas of certain genes being essential for life. For this to work the host must coadadpt, and the endosymbiont must be beneficial to the host.

Well, to just jump right in, I am likely to edit both a subsection of the HGT page, microbes especially, but no, also in animal-animal symbioses, and three ways symbioses including microbes and animals. So yes, I will pepper contributions into this page.

But how to talk about it? Well, there's... gene's that aren't selected for, so they fade away, but how do they fade away so fast? that is something I should explain.

And how do I keep connected to chemical ecology? Well, I could mention of lichen thalli seem to have transfered all the secondary metabolite genes, at least for defensive purposes, to the mycobiont. And therefore...genes get passed up?