The MaSp1: MaSp2 expression patterns we found across treatments generally did not correspond with the amino acid compositions according to our expectations under a traditional MaSp expression model. For instance, a decreased in alanine and glycine composition in the MA silk of protein deprived A. keyserlingi was not associated with any form of MaSp2 downregulation, but was associated with an upregulation of MaSp1a. The spidroin expression pattern found for E. transmarina across treatments likely explains why the amino acid compositions did not vary across treatments in this spider. The high expression of all of the MaSp1 and MaSp2 paralogs in the MA glands of L. hasselti is consistent with findings for L. hasperus . Expression of multiple MaSp paralogs in the MA glands was not common for most species we assessed, but was pronounced in L. hasselti. The increase in proline composition in protein deprived N. plumipes MA silk conflicts with the findings of Blamires et al. , who found an increase in proline composition in protein deprive N. pilipes. We would have expected the downregulation of MaSp2a expression by this spider when protein deprived to result in a decrease in silk proline composition. The downregulation of MaSp1a on the other hand was unlikely to have any influence on proline composition . An increase in the proline composition in the silks of protein deprived P. graefei, however, may be ascribed to an increased in MaSp2a expression by these spiders.