Favoritos de hmheinz

Got microscope photos of slime mold! First two at 40x, third at 100x, last two at 400x. I may have messed up the order by trying to adjust default (sorry). Will link prior obs in comments. Photos taken after specimen sat out for ~2hr, not sure if relevant.

I managed to catch the moment where two Juniperus virginiana pollen grains' intines expanded and ruptured their exines. I think the first probably helped trigger the second. Check out this paper for more on the mechanism at work here.
Measurements
Unruptured exines
23–27×21–25 μm; Q=1.01–1.15
Images
All slides in water
1: External intines hydrating and expanding to rupture exines
2: Intact pollen grains
3: Ruptured pollen grains
4: Habit

More phages from the deep water of this tea-stained lake. The first shot is of a bacterium captured at the moment of rupture by tailed phages. It looks like they made a pretty efficient transfer of bacterium to phage biomass. The burst size of 10 (if none were lost) is in line with other observations from nutrient-poor lakes. Next is a close-up of a tailless phage. The capsomeres are clearly evident, suggesting that this one is a single-stranded DNA virus of the Microviridae (I'm just guessing here). Number three has a long, non-contractile tail. That makes it a siphovirus. Four appears to have a contractile tail that will allow it to inject its DNA hypodermic-style. Nice head. Then two attached phages. Many bacterial cells seemed to have attached phages - hard to explain. Finally, an interesting community of viruses, tailed and tailless, on what might be a conjugation tube that is used to transfer DNA between bacterial cells. Conjugation is a handy way to pass on genes to confer immunity to phages. But it comes with a tradeoff - phages attach to the tube to inject their own nucleic acids. I like the curious structure of the lengthened icosahedra (?) of some of the phages.