The isocitrate dehydrogenase gene of oleaginous yeast Lipomyces starkeyi is linked to lipid accumulation

2009 ◽  
Vol 55 (9) ◽  
pp. 1062-1069 ◽  
Author(s):  
Wei Tang ◽  
Sufang Zhang ◽  
Qian Wang ◽  
Haidong Tan ◽  
Zongbao Kent Zhao

The oleaginous yeast Lipomyces starkeyi can accumulate intracellular lipids to over 60% of its cell dry mass under a nitrogen-limited condition. We showed that extracellular and intracellular citrate concentrations of L. starkeyi AS 2.1560 increased and the nicotinamide adenine dinucleotide – isocitrate dehydrogenase (NAD+–IDH) activity decreased at the beginning of the lipid accumulation, suggesting that the attenuation of the NAD+–IDH activity might initiate lipid storage. We next cloned the IDH gene by the methods of degenerate PCR and rapid amplification of cDNA ends. Phylogenetic analyses of the evolutionary relationships among LsIDH1, LsIDH2, and other yeast NAD+–IDHs revealed that the L. starkeyi IDH had a closer relationship with the IDHs of Yarrowia lipolytica . Further real-time PCR analysis showed that the expression levels of both LsIDH1 and LsIDH2 decreased concurrently with the evolution of cellular lipids. Our data should be valuable for understanding the biology of oleaginous yeasts and for further strain engineering of L. starkeyi.

2019 ◽  
Vol 2 (2) ◽  
pp. 51-52
Author(s):  
Zoe Lau ◽  
David Stuart ◽  
Bonnie Mcneil

The goal of this project was to adapt the Yarrowia lipolytica plasmid based CRISPR/Cas9 system for usage in Lipomyces starkeyi. Lipomyces starkeyi is an oleaginous yeast, which synthesizes and stores high amounts of intracellular lipids. This specific yeast can store lipids at concentrations higher than 60% of its dry cell weight. Due to these high concentrations of lipids, L. starkeyi is a desired organism for the production of biofuels and other oleochemicals. However, there is a lack of knowledge and of genetic tools when trying to engineer the cells to produce these lipids for our use. The genome editing tool, CRISPR/Cas9 is efficient and simple, therefore desirable for the engineering of L. starkeyi. The goal was achieved by replacing the Y. lipolytica promoter with a L. starkeyi promoter, inserting guide RNA, as well as confirming cas9 protein expression.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1017
Author(s):  
Hirohisa Mekata ◽  
Tomohiro Okagawa ◽  
Satoru Konnai ◽  
Takayuki Miyazawa

Bovine foamy virus (BFV) is a member of the foamy virus family in cattle. Information on the epidemiology, transmission routes, and whole-genome sequences of BFV is still limited. To understand the characteristics of BFV, this study included a molecular survey in Japan and the determination of the whole-genome sequences of 30 BFV isolates. A total of 30 (3.4%, 30/884) cattle were infected with BFV according to PCR analysis. Cattle less than 48 months old were scarcely infected with this virus, and older animals had a significantly higher rate of infection. To reveal the possibility of vertical transmission, we additionally surveyed 77 pairs of dams and 3-month-old calves in a farm already confirmed to have BFV. We confirmed that one of the calves born from a dam with BFV was infected. Phylogenetic analyses revealed that a novel genotype was spread in Japan. In conclusion, the prevalence of BFV in Japan is relatively low and three genotypes, including a novel genotype, are spread in Japan.


Author(s):  
Ziyu Dai ◽  
Kyle R. Pomraning ◽  
Ellen A. Panisko ◽  
Beth A. Hofstad ◽  
Kristen B. Campbell ◽  
...  

2013 ◽  
Vol 79 (23) ◽  
pp. 7360-7370 ◽  
Author(s):  
John Seip ◽  
Raymond Jackson ◽  
Hongxian He ◽  
Quinn Zhu ◽  
Seung-Pyo Hong

ABSTRACTIn the oleaginous yeastYarrowia lipolytica,de novolipid synthesis and accumulation are induced under conditions of nitrogen limitation (or a high carbon-to-nitrogen ratio). The regulatory pathway responsible for this induction has not been identified. Here we report that the SNF1 pathway plays a key role in the transition from the growth phase to the oleaginous phase inY. lipolytica. Strains with aY. lipolyticasnf1(Ylsnf1) deletion accumulated fatty acids constitutively at levels up to 2.6-fold higher than those of the wild type. When introduced into aY. lipolyticastrain engineered to produce omega-3 eicosapentaenoic acid (EPA),Ylsnf1deletion led to a 52% increase in EPA titers (7.6% of dry cell weight) over the control. Other components of theY. lipolyticaSNF1 pathway were also identified, and their function in limiting fatty acid accumulation is suggested by gene deletion analyses. Deletion of the gene encoding YlSnf4, YlGal83, or YlSak1 significantly increased lipid accumulation in both growth and oleaginous phases compared to the wild type. Furthermore, microarray and quantitative reverse transcription-PCR (qRT-PCR) analyses of theYlsnf1mutant identified significantly differentially expressed genes duringde novolipid synthesis and accumulation inY. lipolytica. Gene ontology analysis found that these genes were highly enriched with genes involved in lipid metabolism. This work presents a new role for Snf1/AMP-activated protein kinase (AMPK) pathways in lipid accumulation in this oleaginous yeast.


Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 726-733 ◽  
Author(s):  
Mengpei Guo ◽  
Yinbing Bian ◽  
Jinjie Wang ◽  
Gangzheng Wang ◽  
Xiaolong Ma ◽  
...  

A new partitivirus named Lentinula edodes partitivirus 1 (LePV1) was isolated from a diseased L. edodes strain with severe degeneration of the mycelium and imperfect browning in bag cultures. The nucleotide sequences of LePV1 dsRNA-1 and dsRNA-2 were determined; they were 2,382 bp and 2,245 bp in length, and each contained a single ORF encoding RNA-dependent RNA polymerase (RdRp) and coat protein (CP), respectively. The purified virus preparation contained isometric particles 34 nm in diameter encapsidating these dsRNAs. Phylogenetic analyses showed LePV1 to be a new member of Betapartitivirus, with the RdRp sequence most closely related to Grapevine partitivirus. RT-PCR analysis showed that 27 of the 56 Chinese L. edodes core collection strains carry LePV1, with the virus being more common in wild strains than cultivated strains. In addition, qPCR analysis suggested that coinfection with L. edodes mycovirus HKB (LeV-HKB) could increase replication of the RdRp gene of LePV1. This study may be essential for the development of more accurate disease diagnostics and the formulation of control strategies for viral diseases in L. edodes.


Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Gang Zhang ◽  
Chao Song ◽  
Ming-Ming Zhao ◽  
Biao Li ◽  
Shun-Xing Guo

AbstractCyclin-dependent kinases (CDKs) play an essential role in cell cycle regulation during the embryonic and postembryonic development of organisms. To better understand the molecular mechanisms of CDKs involved in embryogenesis regulation in the endangered medicinal plant Dendrobium candidum Wall. ex Lindl., a 1229-bp full-length cDNA of an A-type CDK gene, Denca;CDKA;1, was identified using 3′ rapid amplification of cDNA end (RACE) PCR. Denca;CDKA;1 was predicted to encode a 294 amino acid residue-long protein of 33.76 kDa with an isoelectric point of 7.72. The deduced Denca;CDKA;1 protein contained a conserved serine/threonine-protein kinase domain (S-TKc) and a canonical cyclinbinding “PSTAIRE” motif. Multiple sequence alignment indicated that members of CDKA family from various plants exhibited a high degree of sequence identity ranging from 82% to 93%. A neighbor-joining phylogenetic tree showed that Denca;CDKA;1 was clustered into the plant group and was distant from the animal and fungal groups. The modeled three-dimensional structure of Denca;CDKA;1 exhibited the similar functional structure of a fold consisting of β-sheets and α-helices joined by discontinuous random coils forming two relatively independent lobes. Quantitative real-time PCR analysis revealed that Denca;CDKA;1 transcripts were the most abundant in protocorm-like bodies with 4.76 fold, followed by that in roots (4.19 fold), seeds (2.57 fold), and stems (1.57 fold). This study characterized the novel Denca;CDKA;1 gene from D. candidum for the first time and the results will be useful for further functional determination of the gene.


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