Limits...
The Hypocrea jecorina (Trichoderma reesei) hypercellulolytic mutant RUT C30 lacks a 85 kb (29 gene-encoding) region of the wild-type genome.

Seidl V, Gamauf C, Druzhinina IS, Seiboth B, Hartl L, Kubicek CP - BMC Genomics (2008)

Bottom Line: The mutation of the cre1 locus has specifically occurred in RUT C30.Some of the genes that are lacking in RUT C30 could be correlated with pronounced alterations in its phenotype, such as poor growth on alpha-linked oligo- and polyglucosides (loss of maltose permease), or disturbance of osmotic homeostasis.Our data place a general caveat on the use of H. jecorina RUT C30 for further basic research.

View Article: PubMed Central - HTML - PubMed

Affiliation: Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/166-5, A-1060 Wien, Austria. vseidl@mail.zserv.tuwien.ac.at

ABSTRACT

Background: The hypercellulolytic mutant Hypocrea jecorina (anamorph Trichoderma reesei) RUT C30 is the H. jecorina strain most frequently used for cellulase fermentations and has also often been employed for basic research on cellulase regulation. This strain has been reported to contain a truncated carbon catabolite repressor gene cre1 and is consequently carbon catabolite derepressed. To date this and an additional frame-shift mutation in the glycoprotein-processing beta-glucosidase II encoding gene are the only known genetic differences in strain RUT C30.

Results: In the present paper we show that H. jecorina RUT C30 lacks an 85 kb genomic fragment, and consequently misses additional 29 genes comprising transcription factors, enzymes of the primary metabolism and transport proteins. This loss is already present in the ancestor of RUT C30--NG 14--and seems to have occurred in a palindromic AT-rich repeat (PATRR) typically inducing chromosomal translocations, and is not linked to the cre1 locus. The mutation of the cre1 locus has specifically occurred in RUT C30. Some of the genes that are lacking in RUT C30 could be correlated with pronounced alterations in its phenotype, such as poor growth on alpha-linked oligo- and polyglucosides (loss of maltose permease), or disturbance of osmotic homeostasis.

Conclusion: Our data place a general caveat on the use of H. jecorina RUT C30 for further basic research.

Show MeSH

Related in: MedlinePlus

DIC images of spore germination of H. jecorina grown in liquid medium with 1% glucose: (a) QM9414 and (b) RUT C30 and cultires grown under osmotic stress with 10% glucose: (c) QM9414 and (d) RUT C30. (e) Swollwn RUT C30 spores that were unable to germinate underwent autophagic cell death. Bars = 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2483294&req=5

Figure 8: DIC images of spore germination of H. jecorina grown in liquid medium with 1% glucose: (a) QM9414 and (b) RUT C30 and cultires grown under osmotic stress with 10% glucose: (c) QM9414 and (d) RUT C30. (e) Swollwn RUT C30 spores that were unable to germinate underwent autophagic cell death. Bars = 20 μm.

Mentions: In order to learn the reason for the prolonged lag phase in strain RUT C30, we microscopically examined the germination of its spores. This analysis revealed that RUT C30 spores first undergo considerable swelling and increase in size before they start to form a germ tube (Fig. 8). While spores of H. jecorina QM9414 showed a uniform spore diameter of 6 – 10 μm during spore germination, H. jecorina RUT C30 spores swelled up to a diameter of 20 – 30 μm, corresponding to an up to 50 – fold increase of spore volume (Fig. 8a–d). Interestingly, not all RUT C30 spores showed a swelling response and the extent of the swelling varied, resulting in a relatively homogenous distribution of spore diameters from ca. 10 to 25 μm. Germination was observed from swollen and not swollen spores and osmotic stress (10% carbon source) did delay germination but not influence the ratio of swollen to not swollen spores. However, although germination from even extremely swollen spores was observed, apparently not all swollen spores were able to enter the germination phase and during later growth stages a number of large spores that had undergone autophagic cell death [43] could be detected (Fig. 8e). The spore swelling and autophagy of swollen spores in H. jecorina RUT C30 could result in a delay of the formation of an interconnected mycelium and therefore explain the observed prolonged lag phase of RUT C30.


The Hypocrea jecorina (Trichoderma reesei) hypercellulolytic mutant RUT C30 lacks a 85 kb (29 gene-encoding) region of the wild-type genome.

Seidl V, Gamauf C, Druzhinina IS, Seiboth B, Hartl L, Kubicek CP - BMC Genomics (2008)

DIC images of spore germination of H. jecorina grown in liquid medium with 1% glucose: (a) QM9414 and (b) RUT C30 and cultires grown under osmotic stress with 10% glucose: (c) QM9414 and (d) RUT C30. (e) Swollwn RUT C30 spores that were unable to germinate underwent autophagic cell death. Bars = 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2483294&req=5

Figure 8: DIC images of spore germination of H. jecorina grown in liquid medium with 1% glucose: (a) QM9414 and (b) RUT C30 and cultires grown under osmotic stress with 10% glucose: (c) QM9414 and (d) RUT C30. (e) Swollwn RUT C30 spores that were unable to germinate underwent autophagic cell death. Bars = 20 μm.
Mentions: In order to learn the reason for the prolonged lag phase in strain RUT C30, we microscopically examined the germination of its spores. This analysis revealed that RUT C30 spores first undergo considerable swelling and increase in size before they start to form a germ tube (Fig. 8). While spores of H. jecorina QM9414 showed a uniform spore diameter of 6 – 10 μm during spore germination, H. jecorina RUT C30 spores swelled up to a diameter of 20 – 30 μm, corresponding to an up to 50 – fold increase of spore volume (Fig. 8a–d). Interestingly, not all RUT C30 spores showed a swelling response and the extent of the swelling varied, resulting in a relatively homogenous distribution of spore diameters from ca. 10 to 25 μm. Germination was observed from swollen and not swollen spores and osmotic stress (10% carbon source) did delay germination but not influence the ratio of swollen to not swollen spores. However, although germination from even extremely swollen spores was observed, apparently not all swollen spores were able to enter the germination phase and during later growth stages a number of large spores that had undergone autophagic cell death [43] could be detected (Fig. 8e). The spore swelling and autophagy of swollen spores in H. jecorina RUT C30 could result in a delay of the formation of an interconnected mycelium and therefore explain the observed prolonged lag phase of RUT C30.

Bottom Line: The mutation of the cre1 locus has specifically occurred in RUT C30.Some of the genes that are lacking in RUT C30 could be correlated with pronounced alterations in its phenotype, such as poor growth on alpha-linked oligo- and polyglucosides (loss of maltose permease), or disturbance of osmotic homeostasis.Our data place a general caveat on the use of H. jecorina RUT C30 for further basic research.

View Article: PubMed Central - HTML - PubMed

Affiliation: Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/166-5, A-1060 Wien, Austria. vseidl@mail.zserv.tuwien.ac.at

ABSTRACT

Background: The hypercellulolytic mutant Hypocrea jecorina (anamorph Trichoderma reesei) RUT C30 is the H. jecorina strain most frequently used for cellulase fermentations and has also often been employed for basic research on cellulase regulation. This strain has been reported to contain a truncated carbon catabolite repressor gene cre1 and is consequently carbon catabolite derepressed. To date this and an additional frame-shift mutation in the glycoprotein-processing beta-glucosidase II encoding gene are the only known genetic differences in strain RUT C30.

Results: In the present paper we show that H. jecorina RUT C30 lacks an 85 kb genomic fragment, and consequently misses additional 29 genes comprising transcription factors, enzymes of the primary metabolism and transport proteins. This loss is already present in the ancestor of RUT C30--NG 14--and seems to have occurred in a palindromic AT-rich repeat (PATRR) typically inducing chromosomal translocations, and is not linked to the cre1 locus. The mutation of the cre1 locus has specifically occurred in RUT C30. Some of the genes that are lacking in RUT C30 could be correlated with pronounced alterations in its phenotype, such as poor growth on alpha-linked oligo- and polyglucosides (loss of maltose permease), or disturbance of osmotic homeostasis.

Conclusion: Our data place a general caveat on the use of H. jecorina RUT C30 for further basic research.

Show MeSH
Related in: MedlinePlus