het-genes in Aspergillus niger

Károly Pál

János Varga

Fons Debets

Laboratory of Genetics

Wageningen University

2002-2006

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

I. Introduction: occurence and role of het-genes

Life cycle of

Aspergillus (Emericella) nidulans

Importance of incompatibility:

preserving fungal individuality

avoiding infectious genetic elements

(mycoviruses, transposons)

avoiding resource exploitation

Heterokaryon incompatibility is well studied in Neurospora crassa and Podospora anserina,

whereas cell death processes are investigated in Saccharomyces cerevisiae.

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

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

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 (CBS513.88 and ATCC1015)

A. oryzae

A. terreus

N. crassa

P. anserina

S. cerevisiae

1 2 8 973 4 5 6

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

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

comparison of HET- and incompatibility related proteins between two A. nigers

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?

CBS513.88 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQQ---GSSPLPWDKLSSLPIPNed16.3 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQQQQQGSSPLPWDKLSSLPIPInd1.7.3 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIPN402 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIPNed23.2 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIPBra3.1 1 FGAAGHSHVSQQQRPPQQQ----QQQQ-------GSSPLPWDKLSSLPIPGu1.1 1 FSAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIPBra2.2 1 FSAAGHSHGSQQQRPPQQQRPPQQQQQQQ-----GSSPLPWDKLSSLPIPInd1.6.17 1 FSAAGHSHGSQQQRPPQQQ----QRSQQQ-----GSSPLPWDKLSSLPIPBra2.5 1 FSAAGHSHGSQQQRPPQQQ----Q----------GSSPLPWDKLSSLPIPconsensus 1 *.******.********** *..... ****************

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?

CBS513.88 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQQ---GSSPLPWDKLSSLPIPNed16.3 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQQQQQGSSPLPWDKLSSLPIPInd1.7.3 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIPN402 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIPNed23.2 1 FGAAGHSHGSQQQRPPQQQ----QQQQQQQ----GSSPLPWDKLSSLPIPBra3.1 1 FGAAGHSHVSQQQRPPQQQ----QQQQ-------GSSPLPWDKLSSLPIPGu1.1 1 FSAAGHSHGSQQQRPPQQQ----QQQQQQ-----GSSPLPWDKLSSLPIPBra2.2 1 FSAAGHSHGSQQQRPPQQQRPPQQQQQQQ-----GSSPLPWDKLSSLPIPInd1.6.17 1 FSAAGHSHGSQQQRPPQQQ----QRSQQQ-----GSSPLPWDKLSSLPIPBra2.5 1 FSAAGHSHGSQQQRPPQQQ----Q----------GSSPLPWDKLSSLPIPconsensus 1 *.******.********** *..... ****************

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