Non-Unc stable transgenic lines were maintained, and the expression of GFP and mCherry were observed under a Zeiss Axiovision II microscope. Three days later, the number of worms that were L2 or older was recorded as number of survived worms (Ns), and the survival rate was calculated as Ns/Np, which is an estimation of survived worms in the whole population. MT12993 mir-71(n4115) worms were outcrossed with N2 for four generations before any test except the initial screen.
When late, first larval stage (L1) worms sense unfavorable conditions, they enter an alternative and long-lived larval stage called dauer larvae (or dauer diapause). The nematode Caenorhabditis elegans responds to starvation by entering developmental arrest at multiple stages of its life cycle (1). Extreme climate events such as droughts and heatwaves are intensifying under climate change, yet their combined effects on plant recovery remain unclear. These pages contain all relevant country-specific information, including the recovery and resilience plans, the Commission’s assessment of the plans as well as information on payments requested by the Member States and funds paid out by the Commission.
Intestinal miRNAs Play Critical Roles in L1 Starvation Survival.
These results compelled us to examine specific interactions between individual miRNAs and their targets to gain mechanistic insights. This result suggests that miR-71 likely functions upstream of, or in parallel to, HBL-1 in regulating VPC timing. Moreover, the expression of hbl-1 is repressed by let-7 family miRNAs at L3 during normal development, and the hyperactivity of hbl-1 caused by failure of miRNA regulation leads to retarded development (26).
- Wild-type strains A and B are an N2 strain recently obtained from the C.
- We found that ain-1 but not ain-2 mutants displayed a significant reduction in L1 starvation survival rate compared with that of wild type (Fig. 1 A and D).
- MiR-71 represses the expression of age-1 and unc-31 through the actions on their 3′UTR, but miR-71 is not required for arresting M cell division during L1 diapause.
- (A) Differential interference contrast (DIC) images showing L4 worms recovered from 4-d–starved L1 worms.
- ICloud does not provide a way for users to view the backup file.
- We provide evidence that miRNA miR-71 is not required for the animals’ entry into L1 diapause, but plays a critical role in long-term survival by repressing the expression of insulin receptor/PI3K pathway genes and genes acting downstream or in parallel to the pathway.
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). We found that the 3′UTRs of several genes of the InsR pathway, including unc-31, age-1, pdk-1, akt-2, and sgk-1, contain predicted miR-71 targeting sites (as predicted by TargetScan and mirWIP). (H and I) Fluorescence images (H) and statistical data (I) showing that the M cell diveded in fed animals but remained undivided in 4-, 7-, or 11-d–starved L1 wild-type and mir-71(lf) worms. (E) Fluorescence and DIC images showing that the unc-31 3′UTR reporter was repressed in mir-71(+)worms (2/2 transgenic lines) but not in mir-71(lf) worms (4/4 transgenic lines). We found that the poor survival rate of daf-16(mu86)(lf) was further decreased by mir-71(lf) (Fig. 2C), consistent with the notion that a portion of miR-71 activities regulate genes that act in parallel to UNC-31–mediated InsR/PI3K signaling for long-term survival during L1 diapause. Mutating miR-71 drastically reduces the survival rate of animals in L1 diapause, and the effect can be suppressed by mutations of insulin receptor pathway genes age-1 and unc-31.
(E) DIC images showing that hbl-1(RNAi) caused precocious VPC divisions in late L2/early L3 in both wild-type and mir-71(lf) worms recovered from 4 d of L1 starvation. Note that the daf-16(lf) worms recovering from 3 d of L1 starvation displayed a ∼12-h delay in overall development and that the mir-71(lf); daf-16(lf) double mutants displayed an ∼24-h delay. (C) Bar graph showing that the delayed VPC timing defects of mir-71(lf) worms was suppressed by an unc-31(lf) mutation and partially suppressed by an age-1(rf) mutation. In worms that recovered from 4 d of L1 starvation, we also found that a significant portion of the mir-71(lf) mutants displayed egg-laying defects and overproliferating or precociously reflexed gonads.
{The RRF funding amounts shown for measures are based on the initial cost estimates provided by the Member States included in the recovery and resilience plans and may as such differ from finalized Commission financial reports, which follow eventual project implementation. The funding amounts shown reflect the initial cost estimates included in the national recovery and resilience plans. Member States use the funds provided by the Recovery and Resilience Facility to implement ambitious reforms and investment to make their economies and societies more sustainable, resilient and prepared for the green and digital transitions. The Scoreboard gives an overview of progress in implementing the Facility and the national recovery and resilience plans.}
Non-Unc stable transgenic lines were maintained, and the expression of GFP and mCherry were observed under a Zeiss Axiovision II microscope. Three days later, the number of worms that were L2 or older was recorded as number of survived worms (Ns), and the survival rate was calculated as Ns/Np, which is an estimation of survived worms in the whole population. MT12993 mir-71(n4115) worms were outcrossed with N2 for four generations before any test except the initial screen.
When late, first larval stage (L1) worms sense unfavorable conditions, they enter an alternative and long-lived larval stage called dauer larvae (or dauer diapause). The nematode Caenorhabditis elegans responds to starvation by entering developmental arrest at multiple stages of its life cycle (1). Extreme climate events such as droughts and heatwaves are intensifying under climate change, yet their combined effects on plant recovery remain unclear. These pages contain all relevant country-specific information, including the recovery and resilience plans, the Commission’s assessment of the plans as well as information on payments requested by the Member States and funds paid out by the Commission.
Intestinal miRNAs Play Critical Roles in L1 Starvation Survival.
These results compelled us to examine specific interactions between individual miRNAs and their targets to gain mechanistic insights. This result suggests that miR-71 likely functions upstream of, or in parallel to, HBL-1 in regulating VPC timing. Moreover, the expression of hbl-1 is repressed by let-7 family miRNAs at L3 during normal development, and the hyperactivity of hbl-1 caused by failure of miRNA regulation leads to retarded development (26).
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). We found that the 3′UTRs of several genes of the InsR pathway, including unc-31, age-1, pdk-1, akt-2, and sgk-1, contain predicted miR-71 targeting sites (as predicted by TargetScan and mirWIP). (H and I) Fluorescence images (H) and statistical data (I) showing that the M cell diveded in fed animals but remained undivided in 4-, 7-, or 11-d–starved L1 wild-type and mir-71(lf) worms. (E) Fluorescence and DIC images showing that the unc-31 3′UTR reporter was repressed in mir-71(+)worms (2/2 transgenic lines) but not in mir-71(lf) worms (4/4 transgenic lines). We found that the poor survival rate of daf-16(mu86)(lf) was further decreased by mir-71(lf) (Fig. 2C), consistent with the notion that a portion of miR-71 activities regulate genes that act in parallel to UNC-31–mediated InsR/PI3K signaling for long-term survival during L1 diapause. Mutating miR-71 drastically reduces the survival rate of animals in L1 diapause, and the effect can be suppressed by mutations of insulin receptor pathway genes age-1 and unc-31.
(E) DIC images showing that hbl-1(RNAi) caused precocious VPC divisions in late L2/early L3 in both wild-type and mir-71(lf) worms recovered from 4 d of L1 starvation. Note that the daf-16(lf) worms recovering from 3 d of L1 starvation displayed a ∼12-h delay in overall development and that the mir-71(lf); daf-16(lf) double mutants displayed an ∼24-h delay. (C) Bar graph showing that the delayed VPC timing defects of mir-71(lf) worms was suppressed by an unc-31(lf) mutation and partially suppressed by an age-1(rf) mutation. In worms that recovered from 4 d of L1 starvation, we also found that a significant portion of the mir-71(lf) mutants displayed egg-laying defects and overproliferating or precociously reflexed gonads.
{The RRF funding amounts shown for measures are based on the initial cost estimates provided by the Member States included in the recovery and resilience plans and may as such differ from finalized Commission financial reports, which follow eventual project implementation. The funding amounts shown reflect the initial cost estimates included in the national recovery and resilience plans. Member States use the funds provided by the Recovery and Resilience Facility to implement ambitious reforms and investment to make their economies and societies more sustainable, resilient and prepared for the green and digital transitions. The Scoreboard gives an overview of progress in implementing the Facility and the national recovery and resilience plans.}