Clamp connectins
-
Upload
akanksha-rai -
Category
Science
-
view
331 -
download
0
Transcript of Clamp connectins
CLAMP CONNECTIONS
Clamp Connection● It operates to ensure the maintenance of
the dikaryotic condition in each new cell or compartment of the secondary mycelium.
● Structure formed by two hyphal cells of certain fungi.
● Used to create genetic variation like croizer mechanism of sexual reproduction.
● When a binucleate hyphal tip is ready to divide, it arises between the two nuclei and form a hook.
Mechanism of Clamp connection
Role of clamp connection in maintaining a dikaryon
● It is interesting to note that some mycologists have likened these structures to the hooks of the ascogenous hyphae in Ascomycota.
● However, other mycologists have suggested that the similarity is due to convergent evolution.
Dolipore Septum● In some species, the septum wall simply
tapers toward the central pore while in others the septal wall near the pore is thickened to form a characteristic dough nut like or barrel- shaped swelling. This latter type of septum is called a dolipore septum.
● It is a dome- shaped, membranous structure referred to here as the septal pore cap.
● The structure appears to consist of modified endoplasmic reticulum and is an integral and functional part of the septal apparatus.
● Although the caps of some species appear as continuous, non- porous structures, those of most species are perforate.
● In some cases, the perforations are large and of irregular size and spacing while in other cases they are smaller and of regular size and spacing.
Functions of Doliopore Septum● It is probably safe to say that its exact
function remains unclear.● It would seem, however, that the pore cap
acts as a screen or sieve, possibly permitting the passage of some cellular components from one cell to the next while retarding others.
● Various ultrastructural and cytochemical changes also have been reported in doliopore septa during basidiocarp development.