Growth, Differentiation and Sexuality

Mating Types in Euascomycetes 305
Table. 15.3. Genome position of the homologs to C. heterostrophus and M. graminicola MAT flanking genes in Sordariomycetes
and Eurotiomycetes
GAP1 ORF1 MAT BGL1 pal1
P. anserina
LG I I I II I
Supercontig E E G A F
Start 280,606 402,224 79,454 3,309,367 432,338
Stop
C. globosum
283,019 401,468 78,144 3,306,572 430,110
Supercontig 1.3 1.3 1.3 (MAT1-1) 1.3
Start 2,900,141 2,736,033 3,990,896 3,892,526
Stop 2,902,311 2,736,841 3,991,867 3,894,742
Supercontig 1.2 (MAT1-2) 1.2
Start 4,650,124 4,159,504
Stop
N. crassa
4,651,264 4,161,935
LG I I I V I
Supercontig 2 2 5 11 5
Contig 3.22 3.23 3.86 3.199 3.88
Gene number
G. zeae
NCU00553.1 NCU00590.1 NCU1960.1 NCU3641.1 NCU1996.1
Supercontig 5 5 5 2 5
Contig 1.348 1.349 1.358 1.160 1.353
Gene number
M. grisea
FG08638.1 FG08689.1 FG08893.1 FG03570.1 FG08708.1
LG VII VII VII I I
Supercontig 4 33 4 2 2
Contig 2.611 2.1986 2.600 2.264 2.535
Gene number
A. nidulans
MG03048.4 MG10319.4 MG02978.4 MG01441.4 MG02630.4
LG III III III (MAT-2) II III
Supercontig 5 5 5 4 5
Contig 1.80 1.81 1.80 1.63 1.83
Gene number AN4745.2 AN4780.2 AN4734.2 AN3904.2 AN4853.2
tical to the one present in the model organism
C. heterostrophus, the genomic context of the M.
graminicola MAT locus is different from that of C.
heterostrophus, and appears to more closely resemble
the Sordariomycete structure. Three genes were
identified in the region 5 ′ of MAT1-2: APN2, APC5,
and a putative homolog of the palI gene of A. nidulans
(Waalwijk et al. 2002; Fig. 15.3). This difference
from C. heterostrophus may be related to the taxonomic
distance between these two species, since M.
graminicola and Cochliobolus spp. are members of
different, albeit sister clades, i.e., the Dothideales
and Pleosporales, respectively (Liu and Hall 2004).
2. MAT Context in Sordariomycetes
and Eurotiomycetes
The MAT context in Ascomycetes was investigated
first by Butler et al. (2004) in different yeasts
and N. crassa. These authors observed that the
MAT locus of Yarrowia lipolytica lies between the
homologs of S. cerevisiae APN2 and SLA2, two
genes that were identified in the left and right
flanking sequences of N. crassa. This common
structure led the authors to propose that this
configuration may be the ancestral one for all
Ascomycetes. We have compiled the genomic sequences
available from the Broad Institute (http://
www.broad.mit.edu/resources.html) and from the
Podospora Genome Project(http://podospora.igmo
rs.u-psud.fr/) to extend the comparison to other
Euascomycetes. The results are reported in
Fig. 15.3. Remarkably, homologs of APN2 and
SLA2 were found on each side of the MAT locus
in all Sordariomycetes. SLA2 and APN2 are
also linked to E. nidulans MAT-1 and MAT-2,
respectively. Overall, these data support the hypothesis
of Butler et al. (2004). Several additional