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Mating of Chlamydomonas CWminus

Elizabeth Harris chlamy at acpub.duke.edu
Wed Apr 22 10:58:25 EST 1998


>I would like to know if anyone has tried mating of cell wall minus strains
>with Cell wall plus strains. Are cell wall minus strains more sensitive to
>bacterial anitbiotics? Also if anybody has any information on the number of
>genes affected in the cell wall mutants and how these will seggregate in a
>cross.
>
>Kindly send your responses to Subodh at tifrc3.tifr.res.in
>Thanx in advance.
>Subhojit Sen.
>TIFR, Mumbai, India.


Yes, you can mate cw+ x cw strains quite easily.  The only problem I've
encountered is that some cw cultures, notably the original cw15 strain in
our collection as CC-277, have a high proportion of cells that lack
flagella.  Product viability is generally poor, however, and you often will
not get complete tetrads, probably because the cw progeny are more fragile
than wild-type cells.

Most of the known cw mutations segregate 2:2, as single Mendelian markers.
In papers published in the early 1970s, Davies reported that the cw mutants
he analyzed fell into 19 allelic groups, of which probably 8 are identified
by mutants still extant.  However, Davies reported anomalous results with a
few mutants, specifically the generation of wild-type progeny from
self-crosses of cw17, cw18, and cw92.

In my experience, cw15 strains show the same degree of antibiotic
sensitivity as wild-type cells, at least for the usual antibiotics employed
in chloroplast genetics - spectinomycin, streptomycin, erythromycin,
neamine, etc.

The early references:

Davies, D.R. (1972a). Cell wall organization in Chlamydomonas reinhardi.
The role of extra-nuclear systems.  Mol. Gen. Genet. 115, 334-348.

Davies, D.R. (1972b).  Electrophoretic analyses of wall glycoproteins in
normal and mutant cells.  Exp. Cell Res. 73, 512-516.

Davies, D.R., and V. Lyall (1973).  The assembly of a highly ordered
component of the cell wall: the role of heritable factors and of physical
structure.  Mol. Gen. Genet. 124, 21-34.

Davies, D.R., and A. Plaskitt (1971).  Genetical and structural analyses of
cell-wall formation in Chlamydomonas reinhardi.  Genet. Res. 17, 33-43.

Davies, D.R., and K. Roberts (1976).  Genetics of cell wall synthesis in
Chlamydomonas reinhardtii.  In: The Genetics of Algae, ed. R.A. Lewin,
Blackwell Scientific Publications, Oxford, and University of California
Press, Berkeley.  pp. 63-68.

Hyams, J., and D.R. Davies (1972).  The induction and characterisation of
cell wall mutants of Chlamydomonas reinhardi.  Mut. Res. 14, 381-389.



Elizabeth Harris
chlamy at acpub.duke.edu






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