The pCaSpeR (1) and pUAST vectors (2) are two of the most commonly used Drosophila transformation vectors. However, although they have great utility in their current form, their multiple cloning sequences (MCSs) have a limited number of unique restriction sites (Figure 1). This is particularly true for the pUAST vector, whose MCS has only five unique sites. Further, neither of the MCSs in pCaSpeR or pUAST are present in small shuttle or cloning vectors, which is problematic, because the large size (>8 kb) of the transgenesis vectors requires sequence manipulations such as site-directed mutagenesis or deletion dropouts to be done in small plasmid vectors and the modified DNA to be moved to the transgenesis vectors. The lack of matching shuttle vectors further constrains the usable cloning sites and can make moving large genomic fragments between a cloning vector and a transgenesis vector problematic.

Antheraea mylitta is one of the wild nonmulberry silkworms, which produces tasar silk. An EST project has been undertaken to understand the gene expression profile of A. mylitta silk gland. Two cDNA libraries, one from the whole bodies of one-day-old larvae and the other from the silkglands of fifth instar larvae, were constructed and sequenced. A total of 2476 good-quality ESTs (1239 clones) were obtained and grouped into 648 clusters containing 390 contigs and 258 singletons to represent 467 potential unigenes. Forty-five sequences contained putative coding region, and represented potentially novel genes. Among the 648 clusters, 241 were categorized according to Gene Ontology hierarchy and showed presence of several silk and immune-related genes. The A. mylitta ESTs have been organized into a freely available online database “AmyBASE”. These data provide an initial insight into the A. mylitta transcriptome and help to understand the molecular mechanism of silk protein production in a Lepidopteran species.