- PAR ID:
- 10028008
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Cellular Biochemistry
- Volume:
- 118
- Issue:
- 9
- ISSN:
- 0730-2312
- Page Range / eLocation ID:
- 3003 to 3015
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Summary The mitochondrial and chloroplast
mRNA s of the majority of land plants are modified through cytidine to uridine (C‐to‐U)RNA editing. Previously, forward and reverse genetic screens demonstrated a requirement for pentatricopeptide repeat (PPR ) proteins forRNA editing. Moreover, chloroplast editing factorsOZ 1,RIP 2,RIP 9 andORRM 1 were identified in co‐immunoprecipitation (co‐IP) experiments, albeit the minimal complex sufficient for editing activity was never deduced. The current study focuses on isolated, intact complexes that are capable of editing distinct sites. Peak editing activity for four sites was discovered in size‐exclusion chromatography (SEC) fractions ≥ 670 kDa, while fractions estimated to be approximately 413 kDa exhibited the greatest ability to convert a substrate containing the editing siterps14 C80.RNA content peaked in the ≥ 670 kDa fraction. Treatment of active chloroplast extracts withRN ase A abolished the relationship of editing activity with high‐MW fractions, suggesting a structuralRNA component in native complexes. By immunoblotting,RIP 9,OTP 86,OZ 1 andORRM 1 were shown to be present in active gel filtration fractions, thoughOZ 1 andORRM 1 were mainly found in low‐MW inactive fractions. Active editing factor complexes were affinity‐purified using anti‐RIP 9 antibodies, and orthologs to putativeArabidopsis thaliana RNA editing factorPPR proteins,RIP 2,RIP 9,RIP 1,OZ 1,ORRM 1 andISE 2 were identified via mass spectrometry. Western blots from co‐IP studies revealed the mutual association ofOTP 86 andOZ 1 with nativeRIP 9 complexes. Thus,RIP 9 complexes were discovered to be highly associated with C‐to‐URNA editing activity and other editing factors indicative of their critical role in vascular plant editosomes. -
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Abstract Animals that feed socially can sometimes better locate prey, often by transferring information about food that is patchy, dense, and temporally and spatially unpredictable. Information transfer is a potential benefit of living in breeding colonies where unsuccessful foragers can more readily locate successful ones and thereby improve feeding efficiency. Most studies on social foraging have been short term, and how long‐term environmental change affects both foraging strategies and the associated benefits of coloniality is generally unknown. In the colonial Cliff Swallow (
Petrochelidon pyrrhonota ), we examined how social foraging, information transfer, and feeding ecology changed over a 40‐year period in western Nebraska. Relative to the 1980s, Cliff Swallows in 2016–2022 were more likely to forage solitarily or in smaller groups, spent less time foraging, were more successful as solitaries, fed in more variable locations, and engaged less in information transfer at the colony site. The total mass of insects brought back to nestlings per parental visit declined over the study. The diversity of insect families captured increased over time, and some insect taxa dropped out of the diet, although the three most common insect families remained the same over the decades. Nestling Cliff Swallow body mass at 10 days of age and the number of nestlings surviving per nest declined more sharply with colony size in 2015–2022 than in 1984–1991 at sites where the confounding effects of ectoparasites were removed. Adult body mass during the provisioning of nestlings was lower in more recent years, but the change did not vary with colony size. The reason(s) for the reduction in social foraging and information transfer over time is unclear, but the consequence is that colonial nesting may no longer offer the same fitness advantages for Cliff Swallows as in the 1980s. The results illustrate the flexibility of foraging behavior and dynamic shifts in the potential selective pressures for group living.
