How can I get more males?
There are several ways to turn a hermaphrodite population into a male/herm population.
1). Cross in a him mutant (e.g. him-8, http://www.wormbase.org/db/gene/gene?name=WBGene00001867;class=Gene). him = high incidence of males. These mutations typically increase chromosomal non-disjuction, thus creating viable XO embryos which become males.This double will continuously produce males without further matings.
2). Heat-shock L4s at 30-32C for 6 hours or so, then return them to 20C. This also increases non-disjunction. Note that to sustain the male population you will have to continuously set up matings (male + herm).
3). Perform RNAi against a him gene (https://dbw6.msi.umn.edu/cgcdb/strain.php?id=8550). This typically is not efficient. Again, to maintain male population you will have to set up matings.
Hope this helps!
Steve
Steve’s answer should help you with the most likely interpretation of your question.
If instead you want to get a population highly enriched for males, for example for biochemical analysis or transcriptional profiling, Jonathan Hodgkin wrote a Worm Breeder’s Gazette article entitled “Strains for making enriched or pure male samples” (WBG Vol. 15 #5, 1999, p. 19). I’d link to the text, but I couldn’t find it searching in Textpresso, and the Worm Breeder’s Gazette archives seem to be unavailable right now. Basically, he suggests that people consider using CB4951, CB4017, CB4689, or CB5362, all of which are available from the CGC.
Hey thanks a lot guys for your replies.
Just wanted to know what exactly happens in terms of genetic mechanisms that allows a hermaphrodite mother to produce male worms, simply by heat shocking?
Sanjib
It increases the rate of chromosomal non-disjunction (“not coming apart”), which means that during meiosis instead of each daughter getting a single X chromatid, one daughter gets two and one daughter gets none. When the maternal gamete containing no X chromosomes gets fertilized by a paternal gamete containing one X chromosome, the result is an embryo that is XO, or genetically male in C. elegans. (as an aside, the XXX embryo is viable but infertile and extremely Dpy). I hope that explanation is understandable!
Thanks. Appreciate it.