[The intergeneric compatibility of heredity and expression for cellulase genomes between Aspergillus niger and...

By using the developed display techniques of cellulase isozymes and the RAPD-PCR analysis guided by a deduced universal sequence of cellulase genes, the polymorphisms of genomic DNA fingerprints and cellulase isozymes were compared among three typical stable recombinants (3a, 3b, A7-1) and their two parents (Aspergillus niger AMS11, Trichoderma reesei QM9414) in order to provide the molecular evidence of gene recombination, to demonstrate the compatibility of heredity and expression of intergeneric genomes, and to assay on the molecular fundamentals of hybridization dominance. The results showed that in these recombinant strains the recombinantal fingerprints of genomic DNA could be stablly hereditary and the expression of recombinantal CMCase (carboxymethylcellulase) and beta GLase (beta-glucosidase) could be compatibly enhanced. The diversity of molecular fundamentals of cellulase hybridization dominance were (1) the compatible co-existence and enhanced expression of some hereditary beta GLase-coding genes from two parents in recombinant 3b; and (2) the compatibly enhancement of expression between the hereditary genes encoding beta GLase and CMCase from two parents, resulting in the dramatic increase of proteins of corresponding isozymes in recombinants 3a and A7-1. Based on these, a proposal model for the double synergism on cellulase activity in vitro and on its biosynthesis in vivo mediated by beta GLase was suggested. A practical method for assaying on the molecular fundamentals and the stability of hybridization dominance of recombinants was thereby established in this study.