1. Laboratory of Genetics Wageningen University
het-genes in Aspergillus niger
Károly Pál
János Varga
Fons Debets
Laboratory of Genetics
Wageningen University

2. I. Introduction:
- occurence and role of het-genes
- het-genes in the Aspergillus genus
II. Search for and comparison of het-genes and proteins
- search for het- and incompatibility related genes in filamentous fungi and yeast
- comparison of HET- and incompatibility related proteins between two A. nigers
III. Conclusions – future studies

3. I. Introduction: occurence and role of het-genes

4. Life cycle of
Aspergillus (Emericella) nidulans

6. Importance of incompatibility: preserving fungal individuality
avoiding infectious genetic elements
(mycoviruses, transposons)
avoiding resource exploitation

7. Heterokaryon incompatibility is well studied in Neurospora crassa and Podospora anserina,
whereas cell death processes are investigated in Saccharomyces cerevisiae.

8. I. Introduction: het-genes in the Aspergillus genus
Most of the known Aspergillus species are asexual, only the A. nidulans was analyzed until now for the presence of het-genes.
Natural A. niger isolates are highly incompatible with each other.
Genome sequencing projects facilitate research, het- and incompatibility related gene homologs were found in the genome sequence of
A. fumigatus
A. oryzae
A. terreus and
A. niger

9. II. Search for and comparison of het-genes and proteins

10. II. Search for and comparison of het-genes and proteins:
search for het-genes in filamentous fungi and yeast
Genomes of 8 fungal species were scanned:
A. fumigatus
A. nidulans
A. niger (CBS and ATCC1015)
A. oryzae
A. terreus
N. crassa
P. anserina
S. cerevisiae

11. 1 2 3 4 5 6 7 8 9 1 - A. fumigatus 2 - A. nidulans
3 - A. niger (CBS513.88)
4 - A. niger (ATCC1015)
5 - A. oryzae
6 - A. terreus
7 - N. crassa
8 - P. anserina
9 - S. cerevisiae

12. II. Search for and comparison of het-genes and proteins:
comparison of HET- and incompatibility related proteins between two A. nigers

13. The A. niger HET-C protein was analyzed in details.
- already investigated in details in N. crassa (3 alleles) and P. anserina (no allelism)
- in A. niger: different length of glutamine repeats: why?
CBS FGAAGHSHGSQQQRPPQQQ----QQQQQQQQ---GSSPLPWDKLSSLPIP Ned FGAAGHSHGSQQQRPPQQQ----QQQQQQQQQQQGSSPLPWDKLSSLPIP Ind FGAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIP N FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIP Ned FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIP Bra FGAAGHSHVSQQQRPPQQQ----QQQQ GSSPLPWDKLSSLPIP Gu FSAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIP Bra FSAAGHSHGSQQQRPPQQQRPPQQQQQQQ-----GSSPLPWDKLSSLPIP Ind FSAAGHSHGSQQQRPPQQQ----QRSQQQ-----GSSPLPWDKLSSLPIP Bra FSAAGHSHGSQQQRPPQQQ----Q GSSPLPWDKLSSLPIP consensus 1 *.******.********** * ****************

14. The A. niger HET-C protein was analyzed in details.
- already investigated in details in N. crassa and P. anserina
- different length of glutamine repeats: why?
CBS FGAAGHSHGSQQQRPPQQQ----QQQQQQQQ---GSSPLPWDKLSSLPIP Ned FGAAGHSHGSQQQRPPQQQ----QQQQQQQQQQQGSSPLPWDKLSSLPIP Ind FGAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIP N FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIP Ned FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIP Bra FGAAGHSHVSQQQRPPQQQ----QQQQ GSSPLPWDKLSSLPIP Gu FSAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIP Bra FSAAGHSHGSQQQRPPQQQRPPQQQQQQQ-----GSSPLPWDKLSSLPIP Ind FSAAGHSHGSQQQRPPQQQ----QRSQQQ-----GSSPLPWDKLSSLPIP Bra FSAAGHSHGSQQQRPPQQQ----Q GSSPLPWDKLSSLPIP consensus 1 *.******.********** * ****************

15. III. Conclusions
- most of the het-, incompatibility related and PCD homolog genes are present in the Aspergilli including the A. niger
- based on the genome sequences with molecular genetic tools now we can analyze functionality of these genes (i.e. transformations, deletions)
- genome sequences can help us to reveal the secrets of incompatibility in A. niger