scholarly journals Simultaneous Overexpression of Integrated Genes by Copy Number Amplification of a Mini-Yeast Artificial Chromosome

2018 ◽  
Vol 28 (5) ◽  
pp. 821-825
Author(s):  
Heo-Myung Jung ◽  
Yeon-Hee Kim
Nature ◽  
1993 ◽  
Vol 362 (6417) ◽  
pp. 258-261 ◽  
Author(s):  
Andreas Schedl ◽  
Lluís Montoliu ◽  
Gavin Kelsey ◽  
Günther Schütz

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 305-308 ◽  
Author(s):  
Hiroji Chibana ◽  
Elizabeth L Heinecke ◽  
Janna L Beckerman ◽  
Paul T Magee

The pBAC 108L and pFos 1 vectors were developed as stable propagation vectors which, due to their extremely low copy number, facilitate the cloning of a large-sized insert containing repeated DNA. However, the low copy number requires laborious end-DNA preparation for end sequencing and chromosome walking. Here we describe efficient methods for end-DNA isolation. The entire process, including small-scale DNA preparation, restriction digestion, self-ligation, and PCR with vector-based primers, is carried out in 96-well formats. Using a Fosmid library of genomic DNA of Candida albicans, PCR products ranging in size from 0.1 to 8 kbp were generated from 118 end sequences in 140 reactions from 70 Fosmid clones. A single or a prominent band was found in 101 of these reactions. Twenty-six of these bands were tested for walking and all of them proved to be specific. Thus, the system overcomes the disadvantage caused by low copy number. This system allows rapid physical mapping of genomes, and is adaptable for several other vectors including BAC (bacterial artificial chromosome), PAC (P1-derived artificial chromosome) and YAC (yeast artificial chromosome).Key words: IPCR, LM-PCR, chromosome walk, genome project, contig map.


1998 ◽  
Vol 18 (9) ◽  
pp. 5465-5477 ◽  
Author(s):  
Edward B. Cambareri ◽  
Rafael Aisner ◽  
John Carbon

ABSTRACT DNA from the centromere region of linkage group (LG) VII ofNeurospora crassa was cloned previously from a yeast artificial chromosome library and was found to be atypical ofNeurospora DNA in both composition (AT rich) and complexity (repetitive). We have determined the DNA sequence of a small portion (∼16.1 kb) of this region and have identified a cluster of three new retrotransposon-like elements as well as degenerate fragments from the 3′ end of Tad, a previously identified LINE-like retrotransposon. This region contains a novel full-length but nonmobilecopia-like element, designated Tcen, that is only associated with centromere regions. Adjacent DNA contains portions of a gypsy-like element designated Tgl1. A third new element, Tgl2, shows similarity to theTy3 transposon of Saccharomyces cerevisiae. All three of these elements appear to be degenerate, containing predominantly transition mutations suggestive of the repeat-induced point mutation (RIP) process. Three new simple DNA repeats have also been identified in the LG VII centromere region. While Tcenelements map exclusively to centromere regions by restriction fragment length polymorphism analysis, the defective Tad elements appear to occur most frequently within centromeres but are also found at other loci including telomeres. The characteristics and arrangement of these elements are similar to those seen in theDrosophila centromere, but the relative abundance of each class of repeats, as well as the sequence degeneracy of the transposon-like elements, is unique to Neurospora. These results suggest that the Neurospora centromere is heterochromatic and regional in character, more similar to centromeres of Drosophila than to those of most single-cell yeasts.


1994 ◽  
Vol 297 (3) ◽  
pp. 441-445 ◽  
Author(s):  
D Hickman ◽  
A Risch ◽  
V Buckle ◽  
N K Spurr ◽  
S J Jeremiah ◽  
...  

Arylamine N-acetyltransferase is encoded at two loci, AAC-1 and AAC-2, on human chromosome 8. The products of the two loci are able to catalyse N-acetylation of arylamine carcinogens, such as benzidine and other xenobiotics. AAC-2 is polymorphic and individuals carrying the slow-acetylator phenotype are more susceptible to benzidine-induced bladder cancer. We have identified yeast artificial chromosome clones encoding AAC-1 and AAC-2 and have used the cloned DNAs as fluorescent probes for in situ hybridization. The hybridization patterns allow assignment of AAC-1 and AAC-2 to chromosome 8p21.3-23.1, a region in which deletions have been associated with bladder cancer [Knowles, Shaw and Proctor (1993) Oncogene 8, 1357-1364].


Genetics ◽  
1993 ◽  
Vol 134 (3) ◽  
pp. 837-845
Author(s):  
J P Carulli ◽  
D E Krane ◽  
D L Hartl ◽  
H Ochman

Abstract The rates and patterns of molecular evolution in many eukaryotic organisms have been shown to be influenced by the compartmentalization of their genomes into fractions of distinct base composition and mutational properties. We have examined the Drosophila genome to explore relationships between the nucleotide content of large chromosomal segments and the base composition and rate of evolution of genes within those segments. Direct determination of the G + C contents of yeast artificial chromosome clones containing inserts of Drosophila melanogaster DNA ranging from 140-340 kb revealed significant heterogeneity in base composition. The G + C content of the large segments studied ranged from 36.9% G + C for a clone containing the hunchback locus in polytene region 85, to 50.9% G + C for a clone that includes the rosy region in polytene region 87. Unlike other organisms, however, there was no significant correlation between the base composition of large chromosomal regions and the base composition at fourfold degenerate nucleotide sites of genes encompassed within those regions. Despite the situation seen in mammals, there was also no significant association between base composition and rate of nucleotide substitution. These results suggest that nucleotide sequence evolution in Drosophila differs from that of many vertebrates and does not reflect distinct mutational biases, as a function of base composition, in different genomic regions. Significant negative correlations between codon-usage bias and rates of synonymous site divergence, however, provide strong support for an argument that selection among alternative codons may be a major contributor to variability in evolutionary rates within Drosophila genomes.


2006 ◽  
Vol 26 (20) ◽  
pp. 7682-7695 ◽  
Author(s):  
Tomohiro Tsuduki ◽  
Megumi Nakano ◽  
Nao Yasuoka ◽  
Saeko Yamazaki ◽  
Teruaki Okada ◽  
...  

ABSTRACT Human artificial chromosomes (HACs) are promising reagents for the analysis of chromosome function. While HACs are maintained stably, the segregation mechanisms of HACs have not been investigated in detail. To analyze HACs in living cells, we integrated 256 copies of the Lac operator into a precursor yeast artificial chromosome (YAC) containing α-satellite DNA and generated green fluorescent protein (GFP)-tagged HACs in HT1080 cells expressing a GFP-Lac repressor fusion protein. Time-lapse analyses of GFP-HACs and host centromeres in living mitotic cells indicated that the HAC was properly aligned at the spindle midzone and that sister chromatids of the HAC separated with the same timing as host chromosomes and moved to the spindle poles with mobility similar to that of the host centromeres. These results indicate that a HAC composed of a multimer of input α-satellite YACs retains most of the functions of the centromeres on natural chromosomes. The only difference between the HAC and the host chromosome was that the HAC oscillated more frequently, at higher velocity, across the spindle midzone during metaphase. However, this provides important evidence that an individual HAC has the capacity to maintain tensional balance in the pole-to-pole direction, thereby stabilizing its position around the spindle midzone.


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