The “Vampirome”: Transcriptome and proteome analysis of the principal and accessory submaxillary glands of the vampire bat Desmodus rotundus, a vector of human rabies

Abstract

Vampire bats are notorious for being the sole mammals that strictly feed on fresh blood for their survival. While their saliva has been historically associated with anticoagulants, only one antihemostatic (plasminogen activator) has been molecularly and functionally characterized. Here, RNAs from both principal submandibular and accessory glands of Desmodus rotundus were extracted, and ~ 200 million reads were sequenced by Illumina. The principal gland was enriched with plasminogen activators with fibrinolytic properties, members of lipocalin and secretoglobin families, which bind prohemostatic prostaglandins, and endonucleases, which cleave neutrophil-derived procoagulant NETs. Anticoagulant (tissue factor pathway inhibitor, TFPI), vasodilators (PACAP and C-natriuretic peptide), and metalloproteases (ADAMTS-1) were also abundantly expressed. Members of the TSG-6 (anti-inflammatory), antigen 5/CRISP, and CCL28-like (antimicrobial) protein families were also sequenced. Apyrases (which remove platelet agonist ADP), phosphatases (which degrade procoagulant polyphosphates), and sphingomyelinase were found at lower transcriptional levels. Accessory glands were enriched with antimicrobials (lysozyme, defensin, lactotransferrin) and protease inhibitors (TIL-domain, cystatin, Kazal). Mucins, heme-oxygenase, and IgG chains were present in both glands. Proteome analysis by nano LC-MS/MS confirmed that several transcripts are expressed in the glands. The database presented herein is accessible online at http://exon.niaid.nih.gov/transcriptome/D_rotundus/Supplemental-web.xlsx. These results reveal that bat saliva emerges as a novel source of modulators of vascular biology.

Desmolaris, a novel factor XIa anticoagulant from the salivary gland of the vampire bat (Desmodus rotundus) inhibits inflammation and thrombosis in vivo

“…More recently, the first transcriptome analysis of the principal submaxillary gland of D. rotundus was reported. 22 This extensive database identified-among several genes-1 candidate member of the Kunitz family of proteins that was annotated as an anticoagulant based on its similarity to TFPI. 0, 62, 125, 250, 500, and 1000 nM) in 20 mM Tris, 0.15 M NaCl, 0.3% bovine serum albumin, pH 7.4, for 10 minutes at room temperature.…”

“…Interestingly, this marked effect in the aPTT has been observed before with vampire bat saliva, suggesting that Desmolaris accounts for this activity in nature. 19 Whether other molecules identified in the transcriptome analysis of the gland 22 contribute to the anticoagulant activity of saliva remains to be determined. Experiments also demonstrated that inhibition of FXIa by Desmolaris was enhanced 12 times by heparin.…”

“…Several putative inhibitors acting on platelets, neutrophils, and the clotting cascade-in addition to vasodilators-have been identified. 22 Among these molecules, a 2-Kunitzdomain type inhibitor named Desmolaris exhibited similarity to TFPI, the inhibitor of the extrinsic pathway of the coagulation cascade. 12 Our results demonstrate that Desmolaris is a naturally deleted Kunitz-1-domainless form of TFPI that tightly binds FXIa.…”

De novotranscriptome assembly for the spiny mouse (Acomys cahirinus)

“…De novo assembly of millions/billions of RNA-Seq reads into a reference transcriptome can provide a valuable scientific resource, with applications in phylogenetics 36 , novel gene identification 37 , RNA editing 38 and alternative splicing investigation 39 , qPCR primer design 40 , development and refinement of bioinformatics software 41 , augmenting proteomic research 42 , and investigation of gene expression profiles underlying complex physiological traits 43,44 . The utility of a transcriptome assembly is highly dependent on its completeness and accuracy, however there is not yet consensus within the transcriptomics community on a universal 'gold-standard' protocol or quality metric for transcriptome assembly.…”

Salivary Antigen-5/CAP Family Members Are Cu2+-dependent Antioxidant Enzymes That Scavenge O2⨪ and Inhibit Collagen-induced Platelet Aggregation and Neutrophil Oxidative Burst

“…The protein sequences were aligned by the ClustalX software program. The phylogenetic tree was created with the Mega package after 10,000 bootstraps with the neighbor-joining algorithm, using the p-dis-tance model as described (6,29). The bar at the bottom of each tree represents 10% amino acid substitution.…”