skip to main content

Attention:

The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 10:00 PM ET on Friday, December 8 until 2:00 AM ET on Saturday, December 9 due to maintenance. We apologize for the inconvenience.


Title: Metabolic Oscillations in Co-Cultures of Hepatocytes and Mesenchymal Stem Cells: Effects of Seeding Arrangement and Culture Mixing: S EEDING A RRANGEMENT E FFECTS ON C o -C ULTURE S YSTEMS
NSF-PAR ID:
10028008
Author(s) / Creator(s):
 ;  
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
More Like this
  1. Summary

    The mitochondrial and chloroplastmRNAs of the majority of land plants are modified through cytidine to uridine (C‐to‐U)RNAediting. Previously, forward and reverse genetic screens demonstrated a requirement for pentatricopeptide repeat (PPR) proteins forRNAediting. Moreover, chloroplast editing factorsOZ1,RIP2,RIP9 andORRM1 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 siterps14C80.RNAcontent peaked in the ≥ 670 kDa fraction. Treatment of active chloroplast extracts withRNase A abolished the relationship of editing activity with high‐MWfractions, suggesting a structuralRNAcomponent in native complexes. By immunoblotting,RIP9,OTP86,OZ1 andORRM1 were shown to be present in active gel filtration fractions, thoughOZ1 andORRM1 were mainly found in low‐MWinactive fractions. Active editing factor complexes were affinity‐purified using anti‐RIP9 antibodies, and orthologs to putativeArabidopsis thalianaRNAediting factorPPRproteins,RIP2,RIP9,RIP1,OZ1,ORRM1 andISE2 were identified via mass spectrometry. Western blots from co‐IP studies revealed the mutual association ofOTP86 andOZ1 with nativeRIP9 complexes. Thus,RIP9 complexes were discovered to be highly associated with C‐to‐URNAediting activity and other editing factors indicative of their critical role in vascular plant editosomes.

     
    more » « less
  2. Abstract

    Assessing the environmental factors that influence the ability of a threatened species to move through a landscape can be used to identify conservation actions that connect isolated populations. However, direct observations of species' movement are often limited, making the development of alternate approaches necessary. Here we use landscape genetic analyses to assess the impact of landscape features on the movement of individuals between local populations of a threatened snake, the eastern massasauga rattlesnake (Sistrurus catenatus). We linked connectivity data with habitat information from two landscapes of similar size: a large region of unfragmented habitat and a previously studied fragmented landscape consisting of isolated patches of habitat. We used this analysis to identify features of the landscape where modification or acquisition would enhance population connectivity in the fragmented region. We found evidence that current connectivity was impacted by both contemporary land‐cover features, especially roads, and inherent landscape features such as elevation. Next, we derived estimates of expected movement ability using a recently developed pedigree‐based approach and least‐cost paths through the unfragmented landscape. We then used our pedigree and resistance map to estimate resistance polygons of the potential extent forS. catenatusmovement in the fragmented landscape. These polygons identify possible sites for future corridors connecting currently isolated populations in this landscape by linking the impact of future habitat modification or land acquisition to dispersal ability in this species. Overall, our study shows how modeling landscape resistance across differently fragmented landscapes can identify habitat features that affect contemporary movement in threatened species in fragmented landscapes and how this information can be used to guide mitigation actions whose goal is to connect isolated populations.

     
    more » « less