scholarly journals Strcuture and transcription of the nopaline synthase gene region of T-DNA

1983 ◽  
Vol 11 (2) ◽  
pp. 369-385 ◽  
Author(s):  
Michael Bevan ◽  
Wayne M. Barnes ◽  
Marry-Dell Chilton
Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 617-624 ◽  
Author(s):  
S M Williams ◽  
J A Kennison ◽  
L G Robbins ◽  
C Strobeck

Abstract The role of reciprocal recombination in the coevolution of the ribosomal RNA gene family on the X and Y chromosomes of Drosophila melanogaster was assessed by determining the frequency and nature of such exchange. In order to detect exchange events within the ribosomal RNA gene family, both flanking markers and restriction fragment length polymorphisms within the tandemly repeated gene family were used. The vast majority of crossovers between flanking markers were within the ribosomal RNA gene region, indicating that this region is a hotspot for heterochromatic recombination. The frequency of crossovers within the ribosomal RNA gene region was approximately 10(-4) in both X/X and X/Y individuals. In conjunction with published X chromosome-specific and Y chromosome-specific sequences and restriction patterns, the data indicate that reciprocal recombination alone cannot be responsible for the observed variation in natural populations.


Genetics ◽  
1972 ◽  
Vol 71 (3) ◽  
pp. 461-464
Author(s):  
Dragutin J Savic

Abstract A constitutive mutation in the histidine operon in Salmonella leads to a decrease in the recombinant recovery following transduction with P22 phage. This decrease appears to be a true decrease in recombination within the histidine operon and specific to that gene region. In addition, a strain with an unlinked mutation was isolated in which an operator-constitutive mutation is lethal.


Genetics ◽  
2007 ◽  
Vol 177 (2) ◽  
pp. 1071-1085 ◽  
Author(s):  
Jeffrey D. Jensen ◽  
Vanessa L. Bauer DuMont ◽  
Adeline B. Ashmore ◽  
Angela Gutierrez ◽  
Charles F. Aquadro

Phytotaxa ◽  
2018 ◽  
Vol 346 (2) ◽  
pp. 157
Author(s):  
C. BIJEESH ◽  
A. MANOJ KUMAR ◽  
K.B. VRINDA ◽  
C.K. PRADEEP

Two unusual species of Craterellus have been collected numerous times from the evergreen tropical forests in Kerala State, India. The species Craterellus albostrigosus and Craterellus inusitatus are described as new based on morphological and phylogenetic analyses of nrLSU-rDNA gene region. Complete morphological descriptions, photographs and comparisons with similar species are provided as well as a key to the known species of Craterellus from India.


2002 ◽  
Vol 45 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Aleida Vazquez-Macias ◽  
Perla Martinez-Cruz ◽  
Maria Cristina Castaneda-Patlan ◽  
Christine Scheidig ◽  
Jurg Gysin ◽  
...  

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Christine Drengenes ◽  
Tomas M. L. Eagan ◽  
Ingvild Haaland ◽  
Harald G. Wiker ◽  
Rune Nielsen

Abstract Background Studies on the airway microbiome have been performed using a wide range of laboratory protocols for high-throughput sequencing of the bacterial 16S ribosomal RNA (16S rRNA) gene. We sought to determine the impact of number of polymerase chain reaction (PCR) steps (1- or 2- steps) and choice of target marker gene region (V3 V4 and V4) on the presentation of the upper and lower airway microbiome. Our analyses included lllumina MiSeq sequencing following three setups: Setup 1 (2-step PCR; V3 V4 region), Setup 2 (2-step PCR; V4 region), Setup 3 (1-step PCR; V4 region). Samples included oral wash, protected specimen brushes and protected bronchoalveolar lavage (healthy and obstructive lung disease), and negative controls. Results The number of sequences and amplicon sequence variants (ASV) decreased in order setup1 > setup2 > setup3. This trend appeared to be associated with an increased taxonomic resolution when sequencing the V3 V4 region (setup 1) and an increased number of small ASVs in setups 1 and 2. The latter was considered a result of contamination in the two-step PCR protocols as well as sequencing across multiple runs (setup 1). Although genera Streptococcus, Prevotella, Veillonella and Rothia dominated, differences in relative abundance were observed across all setups. Analyses of beta-diversity revealed that while oral wash samples (high biomass) clustered together regardless of number of PCR steps, samples from the lungs (low biomass) separated. The removal of contaminants identified using the Decontam package in R, did not resolve differences in results between sequencing setups. Conclusions Differences in number of PCR steps will have an impact of final bacterial community descriptions, and more so for samples of low bacterial load. Our findings could not be explained by differences in contamination levels alone, and more research is needed to understand how variations in PCR-setups and reagents may be contributing to the observed protocol bias.


1995 ◽  
Vol 27 (4) ◽  
pp. 801-807 ◽  
Author(s):  
Hung-Mei Wang ◽  
Troy Ketela ◽  
Wilfred A. Keller ◽  
Stephen C. Gleddie ◽  
Gregory G. Brown

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