*6.1. Expressed Genes in LOCBE*

Strategies based on expressed sequence tags (EST) were commonly used for identifying a large number of genes in species of interest until the development of high-throughput methods [79]. This approach was used to identify and characterize the major transcripts present in LOCBE [51,53]. Reis and collaborators [47] identified and submitted to GenBank in 2004 sequences from 1270 independent clones assembled into 702 clusters of distinct genes and corresponding proteins such as lipocalins, hemolins, serpins, and other proteins (Table 2). The Lopap whole sequence is identified in GenBank by access number AY908986 [47,51].

Aiming to maximize the identification of putative toxins in *L. obliqua* tissues, Veiga and collaborators constructed separate cDNA libraries from both bristle and tegument mRNAs [49]. These libraries correspond to mRNA isolated from *L. obliqua* bristles and from tegument. A catalog for the transcripts from *L. obliqua* structures showed that lipocalin is the most abundant transcript in this genome. Both cDNA libraries of *L. obliqua* contain sequences with homology to lipocalins. A total of 1152 independent clones from the tegument library and 960 from the bristle library were identified as expressed, yielding 938 and 730 sequences, respectively [49].

In the *L. obliqua* bristles library, over 50% of cDNAs code for a lipocalin, followed by kininogen (16.5%), serine proteases (14.7%). and lectin (5.5%) [49]. Concerning the tegument library, the number of clusters found for serpins is the most abundant (25.8%), followed by serine proteases (16.1%), lipocalin (16%). and lectin (12.9%). These gene sequences from both cDNA libraries were applied independently in GenBank. and they are complementary [47,49,51]. Sequence analysis also showed that Lopap is a member of the lipocalin family of proteins, since it presents an identity of 20% to 59% with other lipocalins [47,51]. Lopap has a serine protease-like activity and acts on prothrombin, such as FXa, in the absence of prothrombinase components [47]. Characterization of the transcripts present in LOCBE showed several kinds of components that distinctly take part in the envenoming. However, the exact toxins involved in the envenomation are not entirely clear so far.
