by Barry Goldman
Almost all multicellular critters known (animals, plants, fungi, algae) go through a microbial stage in their life cycle – gamete or spore. Can you think of a multicellular species or higher taxon that has NEVER been caught going through the microbial stage?
by Monika Buczek — Tuberculosis (TB), is an infectious disease caused by the bacterium Mycobacterium tuberculosis (Mtb). Symptoms of an active TB infection include chronic cough with blood-tinged sputum, fever, and weight loss. In fact, prior to the 1882 discovery of the microbe by Robert Koch, TB was called "consumption" because the rapid rate with which infected patients lost body mass made them appear to be "consumed" by some unknown entity.
by Howard Goldfine — For many bacteria, scarcity of phosphorus—serious though it may sound—is not insurmountable. True, phosphorus is needed for nucleic acids and phospholipids, but many prokaryotes have found a way to reduce their need of this element for phospholipid synthesis. But first, why are there phospholipids in the first…
Not a novel question, but nevertheless …what's the current thinking as to why early RNA life went the way of making double-stranded DNA instead of double-stranded RNA? (Yes, dsRNA is extra stable, but there are ways around that.)
by Merry Youle — The bacterial endosymbionts of insects are a perpetual source of wonderment. We wonder, for example, what is driving the paring down of the genomes in the intracellular world? How far can it go? Is the pattern of gene loss similar from one endosymbiont to the next? Are they on the…
by Elio — The gold ring everyone in cancer chemotherapy is reaching for is the ability to selectively kill cancer cells without damaging normal ones. Easier said than done. So far, clever attempts at delivering potent drugs straight to the cancer cells using techniques such as...
by Elio — Parasites pose a problem for the semantically-oriented microbiologist. There is no question that unicellular parasites such as Giardia, Plasmodium, or Toxoplasma are microbes, thus we can appropriate them with impunity. But what about parasitic worms? They are clearly not microscopic* and are taxonomically apart from parasitic protist. Yet parasitic protists…
the real question: why must all cells of multicellular organisms contain the same genome? is it always this way on earth? 'cause i want to know if a multicelular organism can line up with another and exchange genes cell by cell and remain multicellular.
i should look at fungi.
i suppose bacterial biofilms could be considered an example of this. sort of.
i got to thinking of all this while reading j.t. bonner
Some species of planaria are exclusively asexual. At least in a lab setting.
The planarian detaches its tail end and each half regrows the lost parts by regeneration, allowing adult stem cells to divide and differentiate, thus resulting in two worms.
"the real question: why must all cells of multicellular organisms contain the same genome? is it always this way on earth? 'cause i want to know if a multicelular organism can line up with another and exchange genes cell by cell and remain multicellular.
i should look at fungi."
Lichens. Fungus + algae. No idea whether there's evidence of gene exchange, though. I bet someone has looked into this, wonder if I can find some papers...
Some kinds of planaria completely neuter. At least in laboratory Settings.
Planarian separation its end and each half regrows lost part of the regeneration, to make the adult stem cell division and differentiation, leading to two worms.
perhaps the bedelloid rotifers might fit your profile? bdelloid rotifers reproduce by parthenogenesis. oogenesis proceeds via two mitotic divisions. meiosis is absent, and therefore there is no stage during which chromosome reduction occurs; i.e. no haploid stage.