scholarly journals Nutrition mediates the expression of cultivar–farmer conflict in a fungus-growing ant

2016 ◽  
Vol 113 (36) ◽  
pp. 10121-10126 ◽  
Author(s):  
Jonathan Z. Shik ◽  
Ernesto B. Gomez ◽  
Pepijn W. Kooij ◽  
Juan C. Santos ◽  
William T. Wcislo ◽  
...  

Attine ants evolved farming 55–60 My before humans. Although evolutionarily derived leafcutter ants achieved industrial-scale farming, extant species from basal attine genera continue to farm loosely domesticated fungal cultivars capable of pursuing independent reproductive interests. We used feeding experiments with the basal attineMycocepurus smithiito test whether reproductive allocation conflicts between farmers and cultivars constrain crop yield, possibly explaining why their mutualism has remained limited in scale and productivity. Stoichiometric and geometric framework approaches showed that carbohydrate-rich substrates maximize growth of both edible hyphae and inedible mushrooms, but that modest protein provisioning can suppress mushroom formation. Worker foraging was consistent with maximizing long-term cultivar performance: ant farmers could neither increase carbohydrate provisioning without cultivars allocating the excess toward mushroom production, nor increase protein provisioning without compromising somatic cultivar growth. Our results confirm that phylogenetically basal attine farming has been very successful over evolutionary time, but that unresolved host–symbiont conflict may have precluded these wild-type symbioses from rising to ecological dominance. That status was achieved by the evolutionarily derived leafcutter ants following full domestication of a coevolving cultivar 30–35 Mya after the first attine ants committed to farming.

2007 ◽  
Vol 35 (2) ◽  
pp. 769-772 ◽  
Author(s):  
Attila Megyes ◽  
Tamás Rátonyi ◽  
Dénes Sulyok
Keyword(s):  

2011 ◽  
Vol 48 (No. 1) ◽  
pp. 20-26
Author(s):  
M. Birkás ◽  
T. Szalai ◽  
C. Gyuricza ◽  
M. Gecse ◽  
K. Bordás

This research was instigated by the fact that during the last decade annually repeated shallow disk tillage on the same field became frequent practice in Hungary. In order to study the changes of soil condition associated with disk tillage and to assess it is consequences, long-term tillage field experiments with different levels of nutrients were set up in 1991 (A) and in 1994 (B) on Chromic Luvisol at Gödöllö. The effects of disk tillage (D) and disk tillage combined with loosening (LD) on soil condition, on yield of maize and winter wheat, and on weed infestation were examined. The evaluation of soil condition measured by cone index and bulk density indicated that use of disking annually resulted in a dense soil layer below the disking depth (diskpan-compaction). It was found, that soil condition deteriorated by diskpan-compaction decreased the yield of maize significantly by 20 and 42% (w/w), and that of wheat by 13 and 15% (w/w) when compared to soils with no diskpan-compaction. Averaged over seven years, and three fertilizer levels, the cover % of the total, grass and perennial weeds on loosened soils were 73, 69 and 65% of soils contained diskpan-compaction.


Author(s):  
Kazuho Isono ◽  
Ryo Tsukimoto ◽  
Satoshi Iuchi ◽  
Akihisa Shinozawa ◽  
Izumi Yotsui ◽  
...  

Abstract Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days. To reveal the mechanisms underlying L-heat stress tolerance, we here used a forward genetic screening for sensitive to long-term heat (sloh) mutants and isolated sloh4. The mutant was hypersensitive to L- but not S-heat stress. The causal gene of sloh4 was identical to MIP3 encoding a member of the MAIGO2 (MAG2) tethering complex, which is composed of the MAG2, MIP1, MIP2, and MIP3 subunits and is localized at the endoplasmic reticulum (ER) membrane. Although sloh4/mip3 was hypersensitive to L-heat stress, the sensitivity of the mag2-3 and mip1–1 mutants was similar to that of the wild type. Under L-heat stress, the ER stress and the following unfolded protein response (UPR) were more pronounced in sloh4 than in the wild type. Transcript levels of bZIP60-regulated UPR genes were strongly increased in sloh4 under L-heat stress. Two processes known to be mediated by INOSITOL REQUIRING ENZYME1 (IRE1)—accumulation of the spliced bZIP60 transcript and a decrease in the transcript levels of PR4 and PRX34, encoding secretory proteins—were observed in sloh4 in response to L-heat stress. These findings suggest that misfolded proteins generated in sloh4 under L-heat stress may be recognized by IRE1 but not bZIP28, resulting in initiation of the UPR via activated bZIP60. Therefore, it would be possible that only MIP3 in MAG2 complex has an additional function in L-heat tolerance, which is not related to the ER–Golgi vesicle tethering.


Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 445
Author(s):  
Jessica Cuartero ◽  
Onurcan Özbolat ◽  
Virginia Sánchez-Navarro ◽  
Marcos Egea-Cortines ◽  
Raúl Zornoza ◽  
...  

Long-term organic farming aims to reduce synthetic fertilizer and pesticide use in order to sustainably produce and improve soil quality. To do this, there is a need for more information about the soil microbial community, which plays a key role in a sustainable agriculture. In this paper, we assessed the long-term effects of two organic and one conventional cropping systems on the soil microbial community structure using high-throughput sequencing analysis, as well as the link between these communities and the changes in the soil properties and crop yield. The results showed that the crop yield was similar among the three cropping systems. The microbial community changed according to cropping system. Organic cultivation with manure compost and compost tea (Org_C) showed a change in the bacterial community associated with an improved soil carbon and nutrient content. A linear discriminant analysis effect size showed different bacteria and fungi as key microorganisms for each of the three different cropping systems, for conventional systems (Conv), different microorganisms such as Nesterenkonia, Galbibacter, Gramella, Limnobacter, Pseudoalteromonas, Pantoe, and Sporobolomyces were associated with pesticides, while for Org_C and organic cultivation with manure (Org_M), other types of microorganisms were associated with organic amendments with different functions, which, in some cases, reduce soil borne pathogens. However, further investigations such as functional approaches or network analyses are need to better understand the mechanisms behind this behavior.


2008 ◽  
Vol 82 (17) ◽  
pp. 8500-8508 ◽  
Author(s):  
Haiyan Li ◽  
Kazufumi Ikuta ◽  
John W. Sixbey ◽  
Scott A. Tibbetts

ABSTRACT Murine gammaherpesvirus 68 (γHV68 or MHV68) is genetically related to the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), providing a useful system for in vivo studies of the virus-host relationship. To begin to address fundamental questions about the mechanisms of the establishment of gammaherpesvirus latency, we previously generated a replication-defective γHV68 lacking the expression of the single-stranded DNA binding protein encoded by orf6. In work presented here, we demonstrate that this mutant virus established a long-term infection in vivo that was molecularly identical to wild-type virus latency. Thus, despite the absence of an acute phase of lytic replication, the mutant virus established a chronic infection in which the viral genome (i) was maintained as an episome and (ii) expressed latency-associated, but not lytic replication-associated, genes. Macrophages purified from mice infected with the replication-defective virus harbored viral genome at a frequency that was nearly identical to that of wild-type γHV68; however, the frequency of B cells harboring viral genome was greatly reduced in the absence of lytic replication. Thus, this replication-defective gammaherpesvirus efficiently established in vivo infection in macrophages that was molecularly indistinguishable from wild-type virus latency. These data point to a critical role for lytic replication or reactivation in the establishment or maintenance of latent infection in B cells.


1998 ◽  
Vol 331 (3) ◽  
pp. 733-742 ◽  
Author(s):  
Masafumi YOSHIMURA ◽  
Yoshito IHARA ◽  
Tetsuo NISHIURA ◽  
Yu OKAJIMA ◽  
Megumu OGAWA ◽  
...  

Several sugar structures have been reported to be necessary for haemopoiesis. We analysed the haematological phenotypes of transgenic mice expressing β-1,4 N-acetylglucosaminyltransferase III (GnT-III), which forms bisecting N-acetylglucosamine on asparagine-linked oligosaccharides. In the transgenic mice, the GnT-III activity was elevated in bone marrow, spleen and peripheral blood and in isolated mononuclear cells from these tissues, whereas no activity was found in these tissues of wild-type mice. Stromal cells after long-term cultures of transgenic-derived bone marrow and spleen cells also showed elevated GnT-III activity, compared with an undetectable activity in wild-type stromal cells. As judged by HPLC analysis, lectin blotting and lectin cytotoxicity assay, bisecting GlcNAc residues were increased on both blood cells and stromal cells from bone marrow and spleen in transgenic mice. The transgenic mice displayed spleen atrophy, hypocellular bone marrow and pancytopenia. Bone marrow cells and spleen cells from transgenic mice produced fewer haemopoietic colonies. After lethal irradiation followed by bone marrow transplantation, transgenic recipient mice showed pancytopenia compared with wild-type recipient mice. Bone marrow cells from transgenic donors gave haematological reconstitution at the same level as wild-type donor cells. In addition, non-adherent cell production was decreased in long-term bone marrow cell cultures of transgenic mice. Collectively these results indicate that the stroma-supported haemopoiesis is compromised in transgenic mice expressing GnT-III, providing the first demonstration that the N-glycans have some significant roles in stroma-dependent haemopoiesis.


Endocrinology ◽  
2012 ◽  
Vol 153 (9) ◽  
pp. 4181-4191 ◽  
Author(s):  
Brian J. DeBosch ◽  
Maggie Chi ◽  
Kelle H. Moley

Enterocyte fructose absorption is a tightly regulated process that precedes the deleterious effects of excess dietary fructose in mammals. Glucose transporter (GLUT)8 is a glucose/fructose transporter previously shown to be expressed in murine intestine. The in vivo function of GLUT8, however, remains unclear. Here, we demonstrate enhanced fructose-induced fructose transport in both in vitro and in vivo models of enterocyte GLUT8 deficiency. Fructose exposure stimulated [14C]-fructose uptake and decreased GLUT8 protein abundance in Caco2 colonocytes, whereas direct short hairpin RNA-mediated GLUT8 knockdown also stimulated fructose uptake. To assess GLUT8 function in vivo, we generated GLUT8-deficient (GLUT8KO) mice. GLUT8KO mice exhibited significantly greater jejunal fructose uptake at baseline and after high-fructose diet (HFrD) feeding vs. wild-type mice. Strikingly, long-term HFrD feeding in GLUT8KO mice exacerbated fructose-induced increases in blood pressure, serum insulin, low-density lipoprotein and total cholesterol vs. wild-type controls. Enhanced fructose uptake paralleled with increased abundance of the fructose and glucose transporter, GLUT12, in HFrD-fed GLUT8KO mouse enterocytes and in Caco2 cultures exposed to high-fructose medium. We conclude that GLUT8 regulates enterocyte fructose transport by regulating GLUT12, and that disrupted GLUT8 function has deleterious long-term metabolic sequelae. GLUT8 may thus represent a modifiable target in the prevention and treatment of malnutrition or the metabolic syndrome.


2018 ◽  
Vol 115 (15) ◽  
pp. E3529-E3538 ◽  
Author(s):  
Sarah Smith-Moore ◽  
Stuart J. D. Neil ◽  
Cornel Fraefel ◽  
R. Michael Linden ◽  
Mathieu Bollen ◽  
...  

Adeno-associated virus (AAV) is a small human Dependovirus whose low immunogenicity and capacity for long-term persistence have led to its widespread use as vector for gene therapy. Despite great recent successes in AAV-based gene therapy, further improvements in vector technology may be hindered by an inadequate understanding of various aspects of basic AAV biology. AAV is unique in that its replication is largely dependent on a helper virus and cellular factors. In the absence of helper virus coinfection, wild-type AAV establishes latency through mechanisms that are not yet fully understood. Challenging the currently held model for AAV latency, we show here that the corepressor Krüppel-associated box domain-associated protein 1 (KAP1) binds the latent AAV2 genome at the rep ORF, leading to trimethylation of AAV2-associated histone 3 lysine 9 and that the inactivation of KAP1 repression is necessary for AAV2 reactivation and replication. We identify a viral mechanism for the counteraction of KAP1 in which interference with the KAP1 phosphatase protein phosphatase 1 (PP1) by the AAV2 Rep proteins mediates enhanced phosphorylation of KAP1-S824 and thus relief from KAP1 repression. Furthermore, we show that this phenomenon involves recruitment of the NIPP1 (nuclear inhibitor of PP1)–PP1α holoenzyme to KAP1 in a manner dependent upon the NIPP1 FHA domain, identifying NIPP1 as an interaction partner for KAP1 and shedding light on the mechanism through which PP1 regulates cellular KAP1 activity.


2004 ◽  
Vol 287 (3) ◽  
pp. G734-G741 ◽  
Author(s):  
Junquan Xu ◽  
Gene Lee ◽  
Haimei Wang ◽  
John M. Vierling ◽  
Jacquelyn J. Maher

α-Naphthylisothiocyanate (ANIT) is a hepatotoxin that causes severe neutrophilic inflammation around portal tracts and bile ducts. The chemotactic signals that provoke this inflammatory response are unknown. In this study, we addressed the possibility that ANIT upregulates CXC chemokines in the liver and that these compounds mediate hepatic inflammation and tissue injury after ANIT treatment. Mice treated with a single dose of ANIT (50 mg/kg) exhibited rapid hepatic induction of the CXC chemokine macrophage inflammatory protein-2 (MIP-2). MIP-2 derived primarily from hepatocytes, with no apparent contribution by biliary cells. In ANIT-treated mice, the induction of MIP-2 coincided with an influx of neutrophils to portal zones; this hepatic neutrophil recruitment was suppressed by 50% in mice that lack the receptor for MIP-2 (CXCR2−/−). Interestingly, despite their markedly reduced degree of hepatic inflammation, CXCR2−/− mice displayed just as much hepatocellular injury and cholestasis after ANIT treatment as wild-type mice. Moreover, after long-term exposure, ANIT CXCR2−/− mice developed liver fibrosis that was indistinguishable from that in wild-type mice. In summary, our data show that CXC chemokines are responsible for some of the hepatic inflammation that occurs in response to ANIT but that these compounds are not essential to the pathogenesis of either acute or chronic ANIT hepatotoxicity.


Bragantia ◽  
2010 ◽  
Vol 69 (suppl) ◽  
pp. 9-18 ◽  
Author(s):  
Osvaldo Guedes Filho ◽  
Sidney Rosa Vieira ◽  
Marcio Koiti Chiba ◽  
Célia Regina Grego

It is known, for a long time, that crop yields are not uniform at the field. In some places, it is possible to distinguish sites with both low and high yields even within the same area. This work aimed to evaluate the spatial and temporal variability of some crop yields and to identify potential zones for site specific management in an area under no-tillage system for 23 years. Data were analyzed from a 3.42 ha long term experimental area at the Centro Experimental Central of the Instituto Agronômico, located in Campinas, Sao Paulo State, Brazil. The crop yield data evaluated included the following crops: soybean, maize, lablab and triticale, and all of them were cultivated since 1985 and sampled at a regular grid of 302 points. Data were normalized and analyzed using descriptive statistics and geostatistical tools in order to demonstrate and describe the structure of the spatial variability. All crop yields showed high variability. All of them also showed spatial dependence and were fitted to the spherical model, except for the yield of the maize in 1999 productivity which was fitted to the exponential model. The north part of the area presented repeated high values of productivity in some years. There was a positive cross correlation amongst the productivity values, especially for the maize crops.


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