We further examined worms recovering from 4 d of L1 starvation and found that around 90% of the mir-71(lf) mutants displayed retarded vulval precursor cell (VPC) division, compared with less than 5% in wild type (Fig. 4A). In contrast, the nuclear-localized GFP expression under the control of the 3′UTR of age-1(Fig. 3 C and D) or unc-31 (Fig. 3 E and F) was strongly repressed in the control worms, but prominently derepressed in mir-71(lf) mutant worms. If the 3′UTR of age-1 or unc-31 is repressed by miR-71, the GFP expression will be repressed in tissues where miR-71 is expressed in wild-type worms, but derepressed in the same tissues of mir-71(lf) worms. Among short-lived miRNA mutants, a mir-71 deletion mutant, mir-71(n4115) (referred to as mir-71(lf) hereafter), displayed a severe reduction in L1 starvation survival rate (Table S1 and Fig. 2A).
miR-71 Likely Directly Represses the Expression of age-1 and unc-31 by Acting on Their 3′ Untranslated Regions.
We further found that this survival rate reduction of ain-1 mutants was overcome by ectopic expression of the AIN-2 protein in the intestine but not in the muscle (Fig. 1A and Fig. S1A). In this study, we addressed the questions of whether and how miRNAs impact developmental arrest and the long-term survival of early L1 stage worms in response to food starvation. Furthermore, a recent study suggests that the expression of certain miRNAs is differentially regulated by starvation-induced dauer diapause (15). Consistent with these ideas, several recent lines of evidence suggest that miRNA let-7 and the heterochronic genes lin-42 and hbl-1 are required to regulate the starvation-induced dauer diapause (10–12) and that a number of miRNAs including lin-4 and mir-71 are involved in regulating life span (13, 14).
Given my views on play, you won’t be surprised to learn that I asked the presenters about whether play experiences could qualify as the kinds of responsive, positive, engaged, and empowering interactions they described. I was attending professional development aimed at helping library staff support families from refugee backgrounds, and we were discussing the role that libraries and childcare staff (mostly the latter, based on the mix of the group) can play in helping often highly traumatised communities. A small increase in risk of harm, replicated many times on a massive scale, means harm is certainly occurring. As COVID-19 lockdowns unfolded around the world, and sales of games, puzzles, toys, and other playful artforms spiked, a friend asked me if I felt a sense of validation. And worst of all, a combination of the two, where other players essentially become supporting cast for a scripted victory that is neither earned, nor fun, nor remotely playful – a psychodrama rather than a game, toying with their victims rather than playing with them. Controlling bullies who insist everyone play their way, forcing people to make deals they don’t want and to keep playing even when they aren’t having fun.
Upon entering L1 diapause, RNA polymerase II quickly accumulates and pauses at promoter regions, and this accumulation was speculated to stop transcription and facilitate the immediate reinitiation of gene expression when food becomes available (2). Previous studies showed that the release of postdocking calcium-regulated dense-core vesicles, the insulin receptor (InsR) pathway, the AMPK pathway, and protein chaperones are required for the long-term survival of starved L1 worms (2–4). However, when newly hatched L1 worms encounter an environment with no food, developmental programs arrest and the worm enters L1 diapause. The presented results indicate that interactions between multiple miRNAs and likely a large number of their mRNA targets in multiple pathways regulate the response to starvation-induced L1 diapause. And we need to take seriously that, just as people’s literary diet matters, so does their ludic diet. In fact I still have a ton to say, about play anxiety and devaluation of play, which I’ll have to put into separate posts over the next few days.
- We’re still investigating the ban appeal you submitted for your Activision account on the title(s) listed above.
- Consistent with the observation described above, the 4-d–starved mir-71(lf) mutants recovering on the RNAi control plates displayed the highly penetrant retarded defect in VPC division.
- If you find that a child family member is using an adult account, please contact us.
- The LAB tone curve is mostly me experimenting to see how it affects color saturation, particularly in the Blue and Magenta spectrum, which I often adjust.
- Elegans Genetic Center for many mutants of miRNA and other genes.
