scholarly journals Yeast Artificial Chromosome

2020 ◽  
Author(s):  
Keyword(s):  
Yeast Artificial Chromosome ◽  
Artificial Chromosome

scholarly journals Structure of the Chromosome VII Centromere Region in Neurospora crassa: Degenerate Transposons and Simple Repeats

1998 ◽  
Vol 18 (9) ◽  
pp. 5465-5477 ◽  
Author(s):  
Edward B. Cambareri ◽  
Rafael Aisner ◽  
John Carbon
Keyword(s):  
Neurospora Crassa ◽  
Yeast Artificial Chromosome ◽  
Fragment Length Polymorphism ◽  
Artificial Chromosome ◽  
Polymorphism Analysis ◽  
Dna Repeats ◽  
Centromere Region ◽  
Simple Repeats ◽  
Restriction Fragment Length ◽  
Repeat Induced Point Mutation

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.

scholarly journals Chromosomal localization of human genes for arylamine N-acetyltransferase

1994 ◽  
Vol 297 (3) ◽  
pp. 441-445 ◽  
Author(s):  
D Hickman ◽  
A Risch ◽  
V Buckle ◽  
N K Spurr ◽  
S J Jeremiah ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
In Situ Hybridization ◽  
Yeast Artificial Chromosome ◽  
Chromosomal Localization ◽  
Artificial Chromosome ◽  
Acetylator Phenotype ◽  
Chromosome 8 ◽  
Slow Acetylator ◽  
Human Genes

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].

Compositional heterogeneity and patterns of molecular evolution in the Drosophila genome.

Genetics ◽  
1993 ◽  
Vol 134 (3) ◽  
pp. 837-845
Author(s):  
J P Carulli ◽  
D E Krane ◽  
D L Hartl ◽  
H Ochman
Keyword(s):  
Molecular Evolution ◽  
Base Composition ◽  
Yeast Artificial Chromosome ◽  
Strong Support ◽  
Direct Determination ◽  
Artificial Chromosome ◽  
Significant Heterogeneity ◽  
Sequence Evolution ◽  
Drosophila Genome ◽  
Eukaryotic Organisms

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.

scholarly journals An Artificially Constructed De Novo Human Chromosome Behaves Almost Identically to Its Natural Counterpart during Metaphase and Anaphase in Living Cells

2006 ◽  
Vol 26 (20) ◽  
pp. 7682-7695 ◽  
Author(s):  
Tomohiro Tsuduki ◽  
Megumi Nakano ◽  
Nao Yasuoka ◽  
Saeko Yamazaki ◽  
Teruaki Okada ◽  
...  
Keyword(s):  
Yeast Artificial Chromosome ◽  
Fluorescent Protein ◽  
De Novo ◽  
Artificial Chromosome ◽  
Time Lapse ◽  
Living Cells ◽  
Lac Repressor ◽  
Host Chromosome ◽  
Artificial Chromosomes ◽  
Spindle Midzone

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.

A physical map with yeast artificial chromosome (YAC) clones covering 63% of the 12 rice chromosomes

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Shoko Saji ◽  
Yosuke Umehara ◽  
Baltazar A Antonio ◽  
Hiroko Yamane ◽  
Hiroshi Tanoue ◽  
...  
Keyword(s):  
Genetic Map ◽  
Dna Markers ◽  
Yeast Artificial Chromosome ◽  
Physical Map ◽  
Genome Structure ◽  
Rice Genome ◽  
Artificial Chromosome ◽  
Physical Length ◽  
Rice Chromosomes ◽  
Yac Contig

A new YAC (yeast artificial chromosome) physical map of the 12 rice chromosomes was constructed utilizing the latest molecular linkage map. The 1439 DNA markers on the rice genetic map selected a total of 1892 YACs from a YAC library. A total of 675 distinct YACs were assigned to specific chromosomal locations. In all chromosomes, 297 YAC contigs and 142 YAC islands were formed. The total physical length of these contigs and islands was estimated to 270 Mb which corresponds to approximately 63% of the entire rice genome (430 Mb). Because the physical length of each YAC contig has been measured, we could then estimate the physical distance between genetic markers more precisely than previously. In the course of constructing the new physical map, the DNA markers mapped at 0.0-cM intervals were ordered accurately and the presence of potentially duplicated regions among the chromosomes was detected. The physical map combined with the genetic map will form the basis for elucidation of the rice genome structure, map-based cloning of agronomically important genes, and genome sequencing.Key words: physical mapping, YAC contig, rice genome, rice chromosomes.

scholarly journals The CMT2D Locus: Refined Genetic Position and Construction of a Bacterial Clone-Based Physical Map

1999 ◽  
Vol 9 (6) ◽  
pp. 568-574 ◽  
Author(s):  
Rachel E. Ellsworth ◽  
Victor Ionasescu ◽  
Charles Searby ◽  
Val C. Sheffield ◽  
Valerie V. Braden ◽  
...  
Keyword(s):  
Linkage Analysis ◽  
Yeast Artificial Chromosome ◽  
Sequence Data ◽  
Physical Map ◽  
Muscular Atrophy ◽  
Large Family ◽  
Artificial Chromosome ◽  
Single Chromosome ◽  
Mixed Features ◽  
Bacterial Clone

Charcot-Marie-Tooth (CMT) disease is a progressive neuropathy of the peripheral nervous system, typically characterized by muscle weakness of the distal limbs. CMT is noted for its genetic heterogeneity, with four distinct loci already identified for the axonal form of the disease (CMT2). In 1996, linkage analysis of a single large family revealed the presence of a CMT2 locus on chromosome 7p14 (designatedCMT2D). Additional families have been linked subsequently to the same genomic region, including one with distal spinal muscular atrophy (dSMA) and one with mixed features of dSMA and CMT2; symptoms in both of these latter families closely resemble those seen in the original CMT2D family. There is thus a distinct possibility that CMT2 and dSMA encountered in these families reflect allelic heterogeneity at a single chromosome 7 locus. In the study reported here, we have performed more detailed linkage analysis of the original CMT2D family based on new knowledge of the physical locations of various genetic markers. The region containing the CMT2D gene, as defined by the original family, overlaps with those defined by at least two other families with CMT2 and/or dSMA symptoms. Both yeast artificial chromosome (YAC) and bacterial clone-based [bacterial artificial chromosome (BAC) and P1-derived artificial chromosome (PAC)] contig maps spanning ∼3.4 Mb have been assembled across the combinedCMT2D critical region, with the latter providing suitable clones for systematic sequencing of the interval. Preliminary analyses have already revealed at least 28 candidate genes and expressed-sequence tags (ESTs). The mapping information reported here in conjunction with the evolving sequence data should expedite the identification of the CMT2D/dSMA gene or genes.

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