<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
<META NAME="GENERATOR" CONTENT="GtkHTML/3.28.1">
</HEAD>
<BODY>
Hi Jamie<BR>
<BR>
if you sequenced a male, then there will be nothing W-specific in the genome... there will shared elements though which could be over-represented in the W.<BR>
<BR>
your question is much easier though. we've had 3 approaches that worked.<BR>
<BR>
Hard, molecular approach<BR>
Dissecting the w of a butterfly, cloning and sanger sequencing W-specific repeats (<A HREF="http://www3.interscience.wiley.com/journal/121589905/abstract">Fukova in Applied Entomology</A>)<BR>
Also you can try a AFLP bulk segregation analysis on a family of male and females with the parents. markers on mum and daughters are w linked.<BR>
<BR>
Easy, lethal physiological approach<BR>
Chop it up. There will be two large (yellow or white) bodies in the males. Testis... for us it works well with L3+ even though our moth larvae are much smaller than heliconius larvae<BR>
<BR>
Fiddly, fool-proof cytogenetic approach<BR>
take a spot of hemolymph (no need to kill it). make a squash preparation with lactic orcein. look under 40x. if the nuclei have a big black spot, it's the W body and it's a female... Let me know if you need the protocol (should be in above paper). It's not that fiddly when you learn it and you can process lots of larvae in a day (you can do the microscope work another day)<BR>
<BR>
cheers<BR>
a<BR>
<BR>
<BR>
On Wed, 2010-04-14 at 11:57 +0100, Jamie Walters wrote:
<BLOCKQUOTE TYPE=CITE>
<PRE>
Hello all,
I'm curious to know if anyone has had any success (or informative
failures...?) with developing W-linked markers for Heliconius (or any
butterfly that would be near enough to be useful).
Or, alternatively, if anyone has any particularly clever ideas for
mining the existing genome data for candidate regions I'd be keen to
hear them.
I'm simply interested in being able to sex juveniles and pupae.
Thanks very much,
Jamie
_______________________________________________
HELICONIUS mailing list
<A HREF="mailto:HELICONIUS@ucl.ac.uk">HELICONIUS@ucl.ac.uk</A>
<A HREF="http://www.mailinglists.ucl.ac.uk/mailman/listinfo/heliconius">http://www.mailinglists.ucl.ac.uk/mailman/listinfo/heliconius</A>
</PRE>
</BLOCKQUOTE>
<BR>
</BODY>
</HTML>