While the above caveats may tempt us to think that the RT-PCR analyses yielded largely uncertain results, we found that the expression patterns for P. graeffei aligned exceptionally close to our expectation should the spiders be regulating MaSp1 and MaSp2 expression alone. We expect that such a finding would not have been possible if our primer choices and/or amplifications were compromised in any way. Moreover, our expression values conformed with those reported for the MaSp-a, MaSp-f, and MaSp-g genes by Babb et al.  (although these authors reported a wider range of values for other MaSp loci). We thus expect that the across-treatment expression patterns that we reported for each species to be reliable for the explicit purpose of checking MaSp expression against the amino acid compositions for each species.