scholarly journals GENETIC MAPPING IN SCHIZOSACCHAROMYCES POMBE BY MITOTIC AND MEIOTIC ANALYSIS AND INDUCED HAPLOIDIZATION

Genetics ◽  
1977 ◽  
Vol 87 (3) ◽  
pp. 471-489 ◽  
Author(s):  
Jürg Kohli ◽  
Herbert Hottinger ◽  
Peter Munz ◽  
Andre Strauss ◽  
Pierre Thuriaux
Keyword(s):  
Chromosome Number ◽  
Genetic Mapping ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Genetic Markers ◽  
Genetic Maps ◽  
Deficient Mutant ◽  
Linkage Groups ◽  
Meiotic Analysis ◽  
Haploid Chromosome Number

ABSTRACT The genetic maps of the fission yeast Schizosaccharomyces pombe were extended through the use of haploidization (spontaneous or induced by m-fluorophenylalanine), as well as by tetrad, random spore and mitotic analysis. A new diploidization method utilizing a meiosis-deficient mutant and improved haploidization techniques was employed. As a result of these and previous studies, 118 genetic markers have been assigned to 3 linkage groups. Centromere markers for all 3 chromosomes were identified and genetic maps containing a total of 71 genes were constructed. Our experiments indicate that 3 is very likely to be the haploid chromosome number of S. pombe.

scholarly journals GENETIC MAPPING IN SACCHAROMYCES IV. MAPPING OF TEMPERATURE-SENSITIVE GENES AND USE OF DISOMIC STRAINS IN LOCALIZING GENES

Genetics ◽  
1973 ◽  
Vol 74 (1) ◽  
pp. 33-54
Author(s):  
R K Mortimer ◽  
D C Hawthorne
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Number ◽  
Genetic Mapping ◽  
Genetic Markers ◽  
Genetic Maps ◽  
Temperature Sensitive ◽  
Yeast Saccharomyces Cerevisiae ◽  
Haploid Chromosome Number ◽  
Number Of Genes

ABSTRACT Through use of tetrad, random spore, trisomic, and mitotic analysis procedures a large number of genes, including 48 new genetic markers, were studied for their locations on the genetic maps of the yeast Saccharomyces cerevisiae. Eighteen new centromere linked genes were discovered and all but one was located on various ones of the 16 previously-established chromosomes. Five fragments of linked genes were also assigned to chromosomes; four were located on known chromosomes while the fifth determined one arm of a new chromosome. The experiments indicate that seventeen is likely to be the haploid chromosome number in this yeast. Most chromosomes have been established by genetic means to be metacentric and their genetic lengths vary from 5 cM to approximately 400 cM. Functionally-related sets of genes generally were found to be dispersed over the genome.

scholarly journals Genetic analysis of phenotype in Trypanosoma brucei : a classical approach to potentially complex traits

2002 ◽  
Vol 357 (1417) ◽  
pp. 89-99 ◽  
Author(s):  
Andy Tait ◽  
Dan Masiga ◽  
Johnstone Ouma ◽  
Annette MacLeod ◽  
Juergen Sasse ◽  
...  
Keyword(s):  
Genetic Mapping ◽  
Trypanosoma Brucei ◽  
Complex Traits ◽  
Positional Cloning ◽  
Genetic Maps ◽  
Linkage Groups ◽  
Physical Size ◽  
Large Numbers ◽  
Number Of Genes ◽  
Allelic Segregation

The genome of the African trypanosome, Trypanosoma brucei , is currently being sequenced, raising the question of how the data generated can be used to determine the function of the large number of genes that will be identified. There is a range of possible approaches, and in this paper we discuss the use of a classical genetic approach coupled with positional cloning based on the ability of trypanosomes to undergo genetic exchange. The genetics of these parasites is essentially similar to a conventional diploid Mendelian system with allelic segregation and an independent assortment of markers on different chromosomes. Data are presented showing that recombination occurs between markers on the same chromosome allowing the physical size of the unit of recombination to be determined. Analysis of the available progeny clones from a series of crosses shows that, in principal, large numbers of progeny can readily be isolated from existing cryopreserved products of mating and, taking these findings together, it is clear that genetic mapping of variable phenotypes is feasible. The available phenotypes for analysis are outlined and most are relevant to the transmission and pathogenesis of the parasite. Genetic maps from two crosses are presented based on the use of the technique of AFLP; these maps comprise 146 and 139 markers in 30 and 21 linkage groups respectively. Segregation distortion is exhibited by some of the linkage groups and the possible reasons for this are discussed. The general conclusion, from the results presented, is that a genetic-mapping approach is feasible and will, in the future, allow the genes determining a number of important traits to be identified.

scholarly journals A Detailed Linkage Map of Medaka, Oryzias latipes: Comparative Genomics and Genome Evolution

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1773-1784 ◽  
Author(s):  
Kiyoshi Naruse ◽  
Shoji Fukamachi ◽  
Hiroshi Mitani ◽  
Mariko Kondo ◽  
Tomoko Matsuoka ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Linkage Group ◽  
Chromosome Number ◽  
Linkage Map ◽  
Backcross Progeny ◽  
Oryzias Latipes ◽  
Linkage Groups ◽  
Conserved Synteny ◽  
Mapping Data ◽  
Haploid Chromosome Number

Abstract We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.

scholarly journals Mitotic mapping ofSchizosaccharomyces pombe

1970 ◽  
Vol 16 (2) ◽  
pp. 127-144 ◽  
Author(s):  
Miguel Flores da Cunha
Keyword(s):  
Genetic Mapping ◽  
Fission Yeast ◽  
Genetic Markers ◽  
Mechanism Of Action ◽  
Genetic Identification ◽  
Crossing Over ◽  
Cell Divisions ◽  
Progressive Loss ◽  
Diploid Cells ◽  
Linkage Relationships

SUMMARYGenetic mapping by means of mitotic haploidization (induced by parafluoropkenylalanine) and mitotic crossing-over was carried out with the fission yeastSchizosaccharomyces pombe. Thirty-two different genetic markers were involved in this investigation; some meiotic linkage relationships had been previously reported (Leupold, Megnet) for 16 of these loci. Mitotic haploidization experiments resulted in the genetic identification of six chromosomes in the haploid complement.Furthermore, in an attempt to study the mechanism of action of parafluorophenylalanine (pFPA) on mitotic haploidization, pedigree analyses were performed by micromanipulation of diploid cells growing in the presence of pFPA. Haploid cells were detected after 40 hours of contact with the analogue and many lethal pedigree branches were observed. These observations seem to agree with Käfer's (1961) and Lhoa's (1968) suggestion that mitotic haploidization in Fungi is achieved by progressive loss of chromosomes throughout cell divisions.

scholarly journals Sexual and parasexual analysis of Ustilago violacea

1969 ◽  
Vol 14 (3) ◽  
pp. 195-221 ◽  
Author(s):  
A. W. Day ◽  
J. K. Jones
Keyword(s):  
Chromosome Number ◽  
Host Plant ◽  
High Frequency ◽  
Linkage Data ◽  
Crossing Over ◽  
Meiotic Segregation ◽  
Linkage Groups ◽  
Haploid Chromosome Number ◽  
Ustilago Violacea ◽  
Anther Smut

Forty-two mutants of the anther smut fungus Ustilago violacea were mapped by means of complementation tests, mitotic haploidization, and meiotic segregation. Spontaneous mitotic haploidization was very rare, but haploids were induced at a high frequency using p–fluorophenylalanine (PFP). Haploid segregants appeared as fast-growing, spherical colonies (papillae) which grew away from the diploid growth on PFP medium. Thirty-three markers, classified by complementation tests into 21 genes, were mapped by mitotic haploidization in 10–12 linkage groups. There were no discrepancies in the linkage data, and all the markers could be assigned unequivocally to linkage groups. Although about 250 diploids were analysed, there were no segregants in which mitotic crossing-over and mitotic haploidization appeared to have occurred simultaneously.Thirteen of the 33 markers, in six or seven genes, were expressed infrequently (0–5%) in the papillae produced on PFP medium. These markers, which behaved unusually and were designated missing-markers, were found to be on two chromosomes which tended to remain disomic on PFP medium. Thus 8–10 chromosomes haploidize readily on PFP medium, whereas two other chromosomes are resistant to the effects of PFP and remain disomic. Meiotic segregation was investigated in crosses of genetically marked haploid stocks and also hi diploids, using the host plant. Some of the results enabled preliminary maps to be made of three linkage groups. The results from meiotic segregation were fully compatible with those from mitotic haploidization and the complementation tests.The genetical evidence for a haploid chromosome number of at least 10–12 is in conflict with the observations of several cytologists that n = 2 in this species.

scholarly journals A long reads-based de-novo assembly of the genome of the Arlee homozygous line reveals chromosomal rearrangements in rainbow trout

2021 ◽  
Author(s):  
Guangtu Gao ◽  
Susana Magadan ◽  
Geoffrey C Waldbieser ◽  
Ramey C Youngblood ◽  
Paul A Wheeler ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Chromosome Number ◽  
Genome Assembly ◽  
De Novo Assembly ◽  
De Novo ◽  
Sequence Data ◽  
Structural Variations ◽  
High Coverage ◽  
Haploid Chromosome Number ◽  
Long Reads

Abstract Currently, there is still a need to improve the contiguity of the rainbow trout reference genome and to use multiple genetic backgrounds that will represent the genetic diversity of this species. The Arlee doubled haploid line was originated from a domesticated hatchery strain that was originally collected from the northern California coast. The Canu pipeline was used to generate the Arlee line genome de-novo assembly from high coverage PacBio long-reads sequence data. The assembly was further improved with Bionano optical maps and Hi-C proximity ligation sequence data to generate 32 major scaffolds corresponding to the karyotype of the Arlee line (2 N = 64). It is composed of 938 scaffolds with N50 of 39.16 Mb and a total length of 2.33 Gb, of which ∼95% was in 32 chromosome sequences with only 438 gaps between contigs and scaffolds. In rainbow trout the haploid chromosome number can vary from 29 to 32. In the Arlee karyotype the haploid chromosome number is 32 because chromosomes Omy04, 14 and 25 are divided into six acrocentric chromosomes. Additional structural variations that were identified in the Arlee genome included the major inversions on chromosomes Omy05 and Omy20 and additional 15 smaller inversions that will require further validation. This is also the first rainbow trout genome assembly that includes a scaffold with the sex-determination gene (sdY) in the chromosome Y sequence. The utility of this genome assembly is demonstrated through the improved annotation of the duplicated genome loci that harbor the IGH genes on chromosomes Omy12 and Omy13.

scholarly journals Upstream – News in Genomics

2002 ◽  
Vol 3 (3) ◽  
pp. 221-225
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ovarian Cancer ◽  
Oryza Sativa ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Proteomic Analysis ◽  
Large Scale ◽  
Protein Complexes ◽  
The Other ◽  
Blood Samples

In recent months a bumper crop of genomes has been completed, including the fission yeast (Schizosaccharomyces pombe) and rice (Oryza sativa). Two large-scale studies ofSaccharomyces cerevisiaeprotein complexes provided a picture of the eukaryotic proteome as a network of complexes. Amongst the other stories of interest was a demonstration that proteomic analysis of blood samples can be used to detect ovarian cancer, perhaps even as early as stage I.

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