|
(click
on the main point headings to jump to the selected
location in the notes)
Characteristics
of "Fungal" Pheromones
1.
Relatively low mw
2.
Produced and released in response to
external conditions (sometimes even mating
partner)
3.
Passively transported to mating
partner where it elicits specific
morphogenetic and biochemical responses
4.
The best known systems:
a.
Sirenin (chemotaxis) system in Allomyces
(Chytridiomycota)
b.
Steroid sex hormone system of Achlya
(Oomycota)
c.
Trisporic acid systems of the
Mucorales (Zycomycota)
d.
Peptide mating factor system in S.
cerevisiae and other Hemiascomycotina
and Hetero-
basidiomycotina
429
(Back
to main points)
Mating-type TA system
1.
Subject to overriding nutritional
control (probably catabolite repression)
2.
Plus 2 other repression systems that
--> p+ & p- prohormones
a.
these are insensitive to derepression
by TA (derepression is by appropriate
prohormone)
b.
act differently in the two mating
types*
* in plus strains repression
prevents synthesis of enzymes necessary to
form 4 keto group of TA
* in minus strains it prevents
the synthesis of the enzymes forming the
1-carboxyl group
443
(Back
to main points)
|
