scholarly journals Laboratory evolution of aSaccharomyces cerevisiaexS. eubayanushybrid under simulated lager-brewing conditions: genetic diversity and phenotypic convergence

2018 ◽  
Author(s):  
Arthur R. Gorter de Vries ◽  
Maaike A. Voskamp ◽  
Aafke C. A. van Aalst ◽  
Line H. Kristensen ◽  
Liset Jansen ◽  
...  

AbstractSaccharomyces pastorianuslager-brewing yeasts are domesticated hybrids ofS. cerevisiaexS. eubayanusthat display extensive inter-strain chromosome copy number variation and chromosomal recombinations. It is unclear to what extent such genome rearrangements are intrinsic to the domestication of hybrid brewing yeasts and whether they contribute to their industrial performance. Here, an allodiploid laboratory hybrid ofS. cerevisiaeandS. eubayanuswas evolved for up to 418 generations on wort under simulated lager-brewing conditions in six independent sequential batch bioreactors. Characterization of 55 single-cell isolates from the evolved cultures showed large phenotypic diversity and whole-genome sequencing revealed a large array of mutations. Frequent loss of heterozygosity involved diverse, strain-specific chromosomal translocations, which differed from those observed in domesticated, aneuploidS. pastorianusbrewing strains. In contrast to the extensive aneuploidy of domesticatedS. pastorianusstrains, the evolved isolates only showed limited (segmental) aneuploidy. Specific mutations could be linked to calcium-dependent flocculation, loss of maltotriose utilisation and loss of mitochondrial activity, three industrially relevant traits that also occur in domesticatedS. pastorianusstrains. This study indicates that fast acquisition of extensive aneuploidy is not required for genetic adaptation ofS. cerevisiaexS. eubayanushybrids to brewing environments. In addition, this work demonstrates that, consistent with the diversity of brewing strains for maltotriose utilization, domestication under brewing conditions can result in loss of this industrially relevant trait. These observations have important implications for the design of strategies to improve industrial performance of novel laboratory-made hybrids.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qian-Hao Zhu ◽  
Warwick Stiller ◽  
Philippe Moncuquet ◽  
Stuart Gordon ◽  
Yuman Yuan ◽  
...  

Abstract Fiber mutants are unique and valuable resources for understanding the genetic and molecular mechanisms controlling initiation and development of cotton fibers that are extremely elongated single epidermal cells protruding from the seed coat of cottonseeds. In this study, we reported a new fuzzless-tufted cotton mutant (Gossypium hirsutum) and showed that fuzzless-tufted near-isogenic lines (NILs) had similar agronomic traits and a higher ginning efficiency compared to their recurrent parents with normal fuzzy seeds. Genetic analysis revealed that the mutant phenotype is determined by a single incomplete dominant locus, designated N5. The mutation was fine mapped to an approximately 250-kb interval containing 33 annotated genes using a combination of bulked segregant sequencing, SNP chip genotyping, and fine mapping. Comparative transcriptomic analysis using 0–6 days post-anthesis (dpa) ovules from NILs segregating for the phenotypes of fuzzless-tufted (mutant) and normal fuzzy cottonseeds (wild-type) uncovered candidate genes responsible for the mutant phenotype. It also revealed that the flanking region of the N5 locus is enriched with differentially expressed genes (DEGs) between the mutant and wild-type. Several of those DEGs are members of the gene families with demonstrated roles in cell initiation and elongation, such as calcium-dependent protein kinase and expansin. The transcriptome landscape of the mutant was significantly reprogrammed in the 6 dpa ovules and, to a less extent, in the 0 dpa ovules, but not in the 2 and 4 dpa ovules. At both 0 and 6 dpa, the reprogrammed mutant transcriptome was mainly associated with cell wall modifications and transmembrane transportation, while transcription factor activity was significantly altered in the 6 dpa mutant ovules. These results imply a similar molecular basis for initiation of lint and fuzz fibers despite certain differences.


2021 ◽  
Vol 22 (9) ◽  
pp. 4732
Author(s):  
Vincenza Ylenia Cusenza ◽  
Alessandra Bisagni ◽  
Monia Rinaldini ◽  
Chiara Cattani ◽  
Raffaele Frazzi

The cytogenetic and molecular assessment of deletions, amplifications and rearrangements are key aspects in the diagnosis and therapy of cancer. Not only the initial evaluation and classification of the disease, but also the follow-up of the tumor rely on these laboratory approaches. The therapeutic choice can be guided by the results of the laboratory testing. Genetic deletions and/or amplifications directly affect the susceptibility or the resistance to specific therapies. In an era of personalized medicine, the correct and reliable molecular characterization of the disease, also during the therapeutic path, acquires a pivotal role. Molecular assays like multiplex ligation-dependent probe amplification and droplet digital PCR represent exceptional tools for a sensitive and reliable detection of genetic alterations and deserve a role in molecular oncology. In this manuscript we provide a technical comparison of these two approaches with the golden standard represented by fluorescence in situ hybridization. We also describe some relevant targets currently evaluated with these techniques in solid and hematologic tumors.


1985 ◽  
Vol 229 (3) ◽  
pp. 587-593 ◽  
Author(s):  
A R Rhoads ◽  
M Lulla ◽  
P B Moore ◽  
C E Jackson

Proteins of Mr 68 000, 34 000 and 32 000 were selectively extracted by EGTA from brain cortex. The three proteins that were extracted along with calmodulin were acidic, monomeric, and did not exhibit structural homology, as demonstrated by one-dimensional peptide mapping. The Mr-68 000 protein was purified to homogeneity and had a Stokes radius of 3.54 nm and S20,W value of 5.1S. Purified calmodulin, Mr-68 000 protein and two proteins of Mr 34 000 and Mr 32 000, interacted with the brain particulate fraction, with half-maximal binding occurring at 3.5 microM, 8.3 microM and 150 microM-Ca2+ respectively. Proteins were bound independently of each other and calmodulin. Pretreatment of the particulate fraction with trypsin prevented the Ca2+-dependent binding of calmodulin; however, the binding of the Mr-68 000 protein or the Mr−32 000 and −34 000 proteins was unaffected. The Mr-68 000 protein of bovine brain did not cross-react immunologically with Mr-67 000 calcimedin from chicken gizzard.


1987 ◽  
Vol 493 (1 Cellular and) ◽  
pp. 489-492 ◽  
Author(s):  
CARL E. CREUTZ ◽  
WILLIAM H. MARTIN ◽  
WILLIAM J. ZAKS ◽  
DEBRA S. DRUST ◽  
HELEN C. HAMMAN

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Xelimar Ramirez ◽  
Imeleta Luamanu ◽  
Ruben Michael Ceballos ◽  
Elizabeth Padilla Crespo

Anoxygenic phototrophic purple bacteria are ubiquitous in aquatic and terrestrial environments and demonstrate broad phenotypic diversity. Purple bacteriaderive energy from light under anaerobic conditions via anoxygenic photosynthesis, a process in which water is not the electron donor. It has been suggested that these bacteria are useful for a variety of applications, including: wastewater treatment; heavy metal remediation; nitrogen fixation; and, control of CH4 emissions. In this study, the goal was to isolate and characterize PNSB from shrimp ponds in Thailand. Surface water and sediment were collected. Enrichment cultures were prepared using Pfenning’s mineral media. As indicated by development of reddish color and turbidity, anoxygenic phototrophic growth was observed within two days of incubation. Cultures in liquid media and on solid plates exhibited a deep red or purple color ten weeks post-inoculation. Under light microscopy, enrichments consist of communities dominated by thin, elongated gram-negative cells with granules of elemental sulfur, which are characteristic of purple bacteria. Molecular methods confirm the presence of pufLM, a genetic biomarker for purple bacteria (e.g., Thiohalocapsa marina, Allochromatium vinosum, Roseovarius tolerans). Initial sequencing of key genes (i.e., pufLM) indicate that these environmental samples contain novel isolates or “geographic variants” that have not been previously described. We have developed a few pure cultures of multiple species from these environmental samples. Since shrimp farming is a key industry in southern Thailand, the characterization of the microbial communities in these ecosystems, including anoxygenic phototrophs, will provide insights into how to maintain water quality in these food production systems.


1989 ◽  
Vol 256 (6) ◽  
pp. G1070-G1081 ◽  
Author(s):  
T. Urushidani ◽  
D. K. Hanzel ◽  
J. G. Forte

When isolated rabbit gastric glands were stimulated with histamine plus isobutylmethylxanthine, a redistribution of H+-K+-ATPase, from microsomes to a low-speed pellet, occurred in association with the phosphorylation of an 80-kDa protein (80K) in the apical membrane-rich fraction purified from the low-speed pellet. Histamine alone or dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP), but not carbachol, also stimulated both the redistribution of H+-K+-ATPase and phosphorylation of 80K. Under stimulated conditions, 80K copurified in the apical membrane fraction along with H+-K+-ATPase and actin; whereas purified microsomes from resting stomach were highly enriched in H+-K+-ATPase but contained neither 80K nor actin. Treatment of the apical membranes with detergents, salts, sonication, and so on, led us to conclude that 80K is a membrane protein, unlike actin; however, the mode of association of 80K with membrane differed from H+-K+-ATPase, an integral membrane protein. Isoelectric focusing and peptide mapping revealed that 80K consists of six isomers of slightly differing pI, with 32P occurring only in the three most acidic isomers and exclusively on serine residues. Moreover, stimulation elicited a shift in the amount of 80K isomers, from basic to acidic, as well as phosphorylation. We conclude that 80K is an apical membrane protein in the parietal cell and an important substrate for cAMP-dependent, but not calcium-dependent, pathway of acid secretion.


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