2. Organelles
• Note:
Both
mitochondira
and
chloroplasts
are
semi-‐
autonomous
– each
has
their
own
DNA,
ribosomes,
and
transcripAon
machinery
– can
replicate
independently
of
the
rest
of
the
cell
– most
of
their
proteins
originate
from
the
DNA
in
the
nucleus
of
the
cell
5. Four
Main
Categories
of
Eukaryal
Microbes
Note: highly conserved genes can be used to enhance our understanding of eukaryal
phylogeny (e.g. tubulins, heat shock proteins)"
6. Fungi
-‐-‐
Saccharomyces
cerevisiae
• heterotrophic;
cell
walls
of
chiAn;
used
to
make
bread,
beer,
wine!
• easy,
cheap
tool
to
study
eukaryoAc
structures/gene
expression
• Saccharomyces
can
undergo
meiosis
to
form
an
ascus
• Haploid
maAng
types
can
fuse
to
reproduce
sexually
or
be
maintained
by
asexual
mitosis
•
Saccharomyces
not
limited
to
ascus
formaAo
• budding
off
of
smaller
cells
can
occur
or
fission
of
idenAcally
sized
cells
7. Protozoa
• As
a
whole,
a
(very)
broad
category
• Some
heterotrophic,
some
photosyntheAc
• Variable
cell
walls
• Different
moAlity
strategies
• Different
reproducAon
strategies
• Model
Organism
=
Giardia
lamblia
– geneAcally
“old”,
lacks
mitochondria
– causes
human
disease
8. Slime
Moulds
-‐-‐
Dictyostelium
discoideum
• sAll
protozoan
• model
for
studying
ecology,
cell
moAlity,
and
cell-‐cell
communicaAon
• Has
three
types
of
cycles:
– VegetaAve
cycle:
exists
in
a
haploid
unicellular
form
unAl
condiAons
worsen
then
will
go
to
social
cycle.
– Social
Cycle:
mulAcellular
“slug”
is
formed
with
a
stalk
and
a
fruiAng
bodyspores
form
in
the
fruiAng
body,
restarAng
the
life
cycle
as
haploid
cells
– Sexual
Cycle:
• haploid
cells
can
fuse
into
a
diploid
macrocyst
form
• macrocyst
form
undergoes
meiosis
to
generate
more
haploid
cells
9. Algae
-‐-‐
Chlamydomonas
• Many
mulicellular
with
cellulose
cell
walls
• has
a
two-‐flagella
form
good
for
studying
eukaryal
flagella
biogenesis/funcAon
• durable
and
easy
to
grow
• Chlamydomonas
maintains
a
moAle
haploidstate
• haploid
cells
dierenAate
and
fuse
into
a
diploid
form
in
bad
condiAons–
spore
formaAon
10. EndosymbioAc
Theory
• one
primiAve
microbe
ingested
another,
forming
a
symbiosis
• two
endosymbioAc
events
must
have
occurred:
– Mitochondria
– Chloroplasts
• Evidence
for
EndosymbioAc
Theory:
– mitochondria/chloroplasts
resemble
bacteria
in
both
size
and
shape.
•
double
membranes
• “Cell”
division
with
FtsZ
• each
has
its
own
DNA,
rRNA
more
similar
tobacterial
sequences
than
eukaryal
ones
• circular
chromosome
– EXCEPTION:
Amitochondriates
lack
mitochondria.
Cells
likely
evolved
out
of
using
them
to
obtain
energy.
Ex)
Giardia
11. Diseases
Caused
by
Eukaryal
Microbes
• Protozoa:
– The
tricky
things
about
these
pathogens
is
that
they
are
very
similar
to
the
cells
that
they
are
taking
over
so,
tough
to
harm
it
w/out
harming
human.
Includes:
• Malaria
and
African
Sleeping
Sickness
• Fungi:
– are
less
likely
to
cause
disease,
but
can
do
so
in
immuno-‐compromised
individuals
– Includes:
• Candida
albicans,
causes
oral
thrush
• Epidermophyton
floccosum,
causes
Athlete’s
foot
• Protozoa
and
fungi
can
cause
significant
disease
in
plants
but,
must
wait
for
the
cell
wall
to
become
damaged
– Fungi:
• RHYTISMA
-‐
"tar
spot"
these
are
the
infecAons
on
the
maple
trees.
Means
low
air
polluAon.
• Phytophthora
infestans
-‐
potato
blight
– Protozoa:
• CORDYCEPS
-‐
are
specific
to
each
arthropod.
Cause
them
to
go
mad
and
then
form
a
fruiAng
body
out
of
their
bodies.
12. Beneficial
Roles
of
Eukaryal
Microbes
• primary
producers
provide
energy
• some
algae
produce
great
amounts
of
oxygen
through
photosynthesis
in
the
oceans
• biodegraders
recycle
nutrients
• some
eukaryal
microbes
can
degrade
cellulose,
recycling
plant
macer
becer
than
animals
can
