Electrophoretic variation involving three alleles is described for the duplicated loci for supernatant aspartate aminotransferase (AAT-1,2), from muscle extracts of brook trout. Both loci exhibit largely disomic inheritance. Exceptional progeny types are proposed to be the result of a form of tetrasomic inheritance. Nonrandom segregation was found among the progeny of males doubly heterozygous for AAT markers; where so-called linkage phase was known, this nonrandom assortment was shown to be pseudolinkage (78.9 percent recombination). Analyses of joint segregation of triply heterozygous males for the AAT-(1,2) loci and for the single alpha glycerophosphate dehydrogenase locus (AGP-1) revealed true linkage of AGP-1 with one AAT locus (mean r = 11 percent), but pseudolinkage with the other AAT locus (r = 74 percent). Intraindividual variation for homoeologous multivalent pairing of two acrocentric with two metacentric chromosomes in males, but with bivalent pairing in females, is proposed to account for pseudolinkage and for the tetrasomically inherited types.
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http://dx.doi.org/10.1093/oxfordjournals.jhered.a109354 | DOI Listing |
Microb Cell Fact
April 2024
Christian Doppler Laboratory for Innovative Pichia Pastoris Host and Vector Systems, Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Bellaterra, 08193, Spain.
Background: Most recombinant Komagataella phaffii (Pichia pastoris) strains for protein production are generated by genomic integration of expression cassettes. The clonal variability in gene copy numbers, integration loci and consequently product titers limit the aptitude for high throughput applications in drug discovery, enzyme engineering or most comparative analyses of genetic elements such as promoters or secretion signals. Circular episomal plasmids with an autonomously replicating sequence (ARS), an alternative which would alleviate some of these limitations, are inherently unstable in K.
View Article and Find Full Text PDFNature
May 2024
Department of Microbiology, University of Washington, Seattle, WA, USA.
Streptomyces are a genus of ubiquitous soil bacteria from which the majority of clinically utilized antibiotics derive. The production of these antibacterial molecules reflects the relentless competition Streptomyces engage in with other bacteria, including other Streptomyces species. Here we show that in addition to small-molecule antibiotics, Streptomyces produce and secrete antibacterial protein complexes that feature a large, degenerate repeat-containing polymorphic toxin protein.
View Article and Find Full Text PDFElife
June 2023
Department of Microbiology and Immunology, Doherty Institute, University of Melbourne, Melbourne, Australia.
infections are associated with high mortality rates. Often considered an extracellular pathogen, can persist and replicate within host cells, evading immune responses, and causing host cell death. Classical methods for assessing cytotoxicity are limited by testing culture supernatants and endpoint measurements that do not capture the phenotypic diversity of intracellular bacteria.
View Article and Find Full Text PDFBioresour Technol
June 2023
National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China. Electronic address:
The high cost and process complexity limit the enzymatic extraction of β-glucan. In this study, β-glucan was extracted from oat bran in a two-step enzymatic pathway using a recombinant strain of Aspergillus niger AG11 overexpressing the endogenous xylanase (xynA) and amylolytic enzyme. First, co-optimization of promoter and signal peptide and a fusion of glucoamylase (glaA) fragment were integrated into the β-glucosidase (bgl) locus to improve xynA expression.
View Article and Find Full Text PDFFront Immunol
March 2023
Department of Animal Health, NEIKER-Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Bizkaia, Spain.
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