1

Just to make sure: isn't this an erroneously structured sentence?

In addition to conjugation, transformation and transduction, other less well recognised mechanisms of DNA uptake occur in nature, while other mechanisms of HGT are probably yet to be elucidated, in particular, DNA uptake by eukaryotes:

Vesicle-mediated translocation by a range of gram-negative bacteria such as Neisseria gonorrheae, E. coli and Pseudomonas aeruginosa, which can bud off vesicle structures that contain genetic material (e.g.antibiotic resistance and virulence genes) and then fuse with another bacterium (Dorward et al., 1989; Kadurugamuwa and Beveridge, 1997; Yaron et al., 2000).

(From "Risks from GMOs due to Horizontal Gene Transfer", by Paul Keese)

As I understand, it's the vesicles (that have genetic material) that fuse with another bacterium - but the sentence makes it look like it's the bacteria that fuses with another bacterium.

And why it's plural "bacteria" in the first instance but singular "bacterium" in the second? Maybe this implies that after all it's bacteria that fuses bacteria... but why mention vesicles then..

In short, I'm uncertain which verb phrases does the conjunction and unite, and which it should unite.

If the union is "contain and then fuse", this seems illogical, since "contain" is not a verb denoting action, like "fuse". "Contain" seems to carry the sense "have" in this excerpt, and this does not combine with "fuse", IMHO.

(asked a parallel question at Biology SE)

|improve this question
  • I read it as a noun phrase: translocation by a range of bacteria [ such as N, E, and P, [ which can bud off structures [ that contain ... ] and then fuse with another bacterium ] ]. – Damkerng T. Sep 14 '15 at 4:19
  • @DamkerngT. - I'm trying to fuse it all into a coherent picture.. is it the (initially-mentioned) bacteria that fuse with another bacterium, or the vesicle structures, in your opinion? – CowperKettle Sep 14 '15 at 4:24
  • 2
    I haven't read the whole article, so I could be wrong. At this point, I think the article (paper?) gives examples of bacteria. Each of these bacteria can bud off such structures and then fuse with another bacterium. – Damkerng T. Sep 14 '15 at 4:26
  • @DamkerngT. - I see. I probably should've asked at(?) Biology SE. – CowperKettle Sep 14 '15 at 4:30
  • That could be a good idea! In any case, I believe that many of us here can give you some useful information too. (But we probably have to wait until the sun rises in another part of the world. :-) – Damkerng T. Sep 14 '15 at 4:41
2

As an editor whose wife is doing a postdoc focused mostly on Pseudomonas, here is my interpretation. For the record, I don't know anything about the actual science. [And Wife is skeptical of the proposed mechanism and the out of date articles cited to support this supposedly not yet elucidated process.] But assuming the syntax isn't screwed up, the bacteria are causing a vesicle to form ("bud") on the bacteria's host, and then taking some of the host's DNA when they are fusing with other bacteria after budding. And this is how the host DNA is being spread, which is the main point.

(Each gram-negative bacterium fuses with another bacterium. But collectively, "these" types of bacteria fuse--individually--with another bacterium.)

|improve this answer
  • Thank you! Then the host must also be a bacterium, since the budded-off parts contain virulence and antibiotic resistance genes. – CowperKettle Sep 14 '15 at 8:13
  • 1
    Are you understanding "vesicle structures" to be the direct object of "bud off"? The gram-negative bacteria bud off (i.e. form) vesicle structures? I don't know the science, and understood the sentence to mean that the vesicle structures acted as a foundation for the bacteria, which were forming buds upon those structures. After forming themselves into buds, the gram-negative bacteria were then fusing with other bacteria. Or are the vesicle structures becoming ruptured? – Tᴚoɯɐuo Sep 14 '15 at 12:00
  • @TRomano - a nice point! I never thought of it this way. I imagined that free-flowing bacteria were "sprouting" vesicles out of themselves, not that they were forming vesicles out of the host's membrane in order to escape from the host's cell. – CowperKettle Sep 14 '15 at 12:05
  • 1
    My ignorance of science can be very creative :) I guess we have to find out what is meant by "bud off". Sprout from? Form buds upon? Distort s.t. into a bud-like shape?... – Tᴚoɯɐuo Sep 14 '15 at 12:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.