Affiliation:
1. Department of Biological Sciences, The University of Iowa, Iowa City, Iowa 52242
Abstract
ABSTRACT
Because
Candida dubliniensis
is closely related to
Candida albicans
, we tested whether it underwent white-opaque switching and mating and whether white-opaque switching depended on
MTL
homozygosity and mating depended on switching, as they do in
C. albicans
. We also tested whether
C. dubliniensis
could mate with
C. albicans
. Sequencing revealed that the
MTL
α locus of
C. dubliniensis
was highly similar to that of
C. albicans
. Hybridization with the
MTL
a
1, MTL
a
2, MTL
α
1
, and
MTL
α
2
open reading frames of
C. albicans
further revealed that, as in
C. albicans
, natural strains of
C. dubliniensis
exist as
a
/α,
a
/
a
, and α/α, but the proportion of
MTL
homozygotes is 33%, 10 times the frequency of natural
C. albicans
strains.
C. dubliniensis
underwent white-opaque switching, and, as in
C. albicans
, the switching was dependent on
MTL
homozygosis.
C. dubliniensis
a
/
a
and α/α cells also mated, and, as in
C. albicans
, mating was dependent on a switch from white to opaque. However, white-opaque switching occurred at unusually high frequencies, opaque cell growth was frequently aberrant, and white-opaque switching in many strains was camouflaged by an additional switching system. Mating of
C. dubliniensis
was far less frequent in suspension cultures, due to the absence of mating-dependent clumping. Mating did occur, however, at higher frequencies on agar or on the skin of newborn mice. The increases in
MTL
homozygosity, the increase in switching frequencies, the decrease in the quality of switching, and the decrease in mating efficiency all reflected a general deterioration in the regulation of developmental processes, very probably due to the very high frequency of recombination and genomic reorganization characteristic of
C. dubliniensis
. Finally, interspecies mating readily occurred between opaque
C. dubliniensis
and
C. albicans
strains of opposite mating type in suspension, on agar, and on mouse skin. Remarkably, the efficiency of interspecies mating was higher than intraspecies
C. dubliniensis
mating, and interspecies karyogamy occurred readily with apparently the same sequence of nuclear migration, fusion, and division steps observed during intraspecies
C. albicans
and
C. dubliniensis
mating and
Saccharomyces cerevisiae
mating.
Publisher
American Society for Microbiology
Subject
Molecular Biology,General Medicine,Microbiology
Cited by
108 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献