Genomic organization of the yeast Yarrowia lipolytica

Abstract

We produced electrophoretic karyotypes of the reference strain E150 and of seven other isolates from different geographical origins to study the genomic organization of the dimorphic yeast Yarrowia lipolytica. These karyotypes differed in the number and size of the chromosomal bands. The karyotype of the reference stain E150 consisted of five bands of between 2.6 and 4.9 Mb in size. This strain contained at least five rDNA clusters, from 190 to 620 kb in size, which were scattered over most of the chromosomes. The assignment of 43 markers, including rRNA genes and three centromeres, to the E150 bands defined five linkage groups. Hybridization to the karyotypes of other isolates with pools of markers of each linkage group showed that linkage groups I, II, IV and V were conserved in the strains tested whereas group III was not and was split between at least two chromosomes in most strains. Use of a meganuclease I-SceI site targeted to one locus of E150 linkage group III showed that two chromosomes actually comigrated in band III of this strain. Our results are compatible with six chromosomes defining the haploid complement of strains of Y. lipolytica and that, despite an unprecedented chromosome length polymorphism, the overall structure of the genome is conserved in different isolates.

Characterization of an Extracellular Lipase Encoded by LIP2 in Yarrowia lipolytica

“…pIMR83 contains an xpr6A976::URA3 disruption cassette in which a 976-bp BamHI-HindIII fragment has been deleted and replaced with the 1.7-kb Y. lipolytica URA3 gene (14). The derivative plasmid, pxpr6⌬976::LEU2 (JME337), was constructed by replacing the 1.7-kb BamHI-HindIII URA3 fragment with the 2.7-kb BamHI-HindIII LEU2 fragment from pINA1192 (8). The DNA was digested with DraIII and SphI prior to transformation of the JMY184 strain (PO1d-6-15) and selection of the Leu ϩ transformants.…”

Yarrowia lipolytica: Safety assessment of an oleaginous yeast with a great industrial potential

“…A high level of chromosomal polymorphism was detected among natural strains and segregants of fertile diploids (Casaregola et al, 1997;Naumova et al, 1993). Chromosome size variations may however mostly reflect differences in the number and size of the subtelomeric rDNA clusters, ranging from 1 to 6 (Casaregola et al, 1997;Clare et al, 1986), largely due to recombination between and within the subtelomeric rDNA repeats (Casaregola et al, 1997;Naumova et al, 1993). Linkage groups detected by hybridizing gene probes to chromosomes separated by pulsed field gel electrophoresis tend to be largely conserved among different isolates (Casaregola et al, 1997).…”

Gene order in a 10 275 bp fragment of Yarrowia lipolytica, including adjacent YlURA5 and YlSEC65 genes conserved in four yeast species

“…The size of the Y. lipolytica genome has been estimated to be 21-22 Mb (Casaregola et al, 1997). Taking into account a rDNA cluster size of 3 Mb (slightly overestimated, Casaregola et al, 1997), we obtain a size of 18 Mb.…”

“…Taking into account a rDNA cluster size of 3 Mb (slightly overestimated, Casaregola et al, 1997), we obtain a size of 18 Mb.…”

“…The total haploid genome size is 21-22 Mb for Y. lipolytica (Casaregola et al, 1997) and 12 Mb for K. lactis (Wesolowski-Louwel and Fukuhara, 1995). The electrophoretic patterns of chromosomal DNA suggest that both yeast species contain six DNA bands (numbered I-VI, from smallest to largest) and about 150 genes have been cloned and located physically in each yeast (Wesolowski-Louvel et al, 1996;Casaregola et al, 1997;Domínguez, A., unpublished).data from DNA sequences contained in the databases have been performed by Keogh et al (1998). The global degree of synteny for the conservation, or non-conservation, of neighbouring gene couples between S. cerevisiae and 13 hemiascomycetous yeasts species has also recently been described (Llorente et al, 2000).…”