m>Candida glabratam>, a haploid and opportunistic
fungal pathogen that has not known sexual cycle, has conserved the
majority o
f the genes required
for
mating and cell type identity. The
m>Cm>.
m>glabratam> geno
me contains three
mating-type-like loci called
m>MTL1m>,
m>MTL2m> and
m>MTL3m>. The three loci encode putative transcription
factors,
a1, 伪1 and 伪2 that regulate cell type identity and sexual reproduction in other
fungi like the closely related
m>Saccharomyces cerevisiaem>.
m>MTL1m> can contain either
a or 伪 in
for
mation.
m>MTL2m>, which contains
a in
for
mation and
m>MTL3m> with 伪 in
for
mation, are relatively close to two telo
meres.
m>MTL1m> and
m>MTL2m> are transcriptionally active, while
m>MTL3m> is subject to an inco
mplete silencing nucleated at the telo
mere that depends on the silencing proteins Sir2, Sir3, Sir4, yKu70/80, Ri
f1, Rap1 and Su
m1.
m>C. glabratam> does not see
m to
maintain cell type identity, as cell type-speci
fic genes are expressed regardless o
f the type (or even absence) o
f mating in
for
mation. These data highlight i
mportant di
fferences in the control o
f mating and cell type identity between the non-pathogenic yeast
m>S. cerevisiaem> and
m>C. glabratam>, which
might explain the absence o
f a sexual cycle in
m>C. glabratam>. The
fact that
m>C. glabratam> has conserved the vast
majority o
f the genes involved in
mating
might suggest that so
me o
f these genes perhaps have been rewired to control other processes i
mportant
for the survival inside the host as a co
mmensal or as a hu
man pathogen.
This manuscript is part of the series of works presented at the 鈥淰 International Workshop: Molecular genetic approaches to the study of human pathogenic fungi鈥?(Oaxaca, Mexico, 2012).
