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Updated: Jun 22

Molecular mechanisms influencing toxin gene expression and protein abundance in venom variation of five lineages of the Crotalus molossus complex


Bledsoe, Richard Dale



Borja-Jiménez, Miguel                                                                                                                                  

Facultad de Ciencias Biológicas                                                                                                                

Universidad Juárez del Estado de Durango                                                                                                         

Av. Universidad s/n. Fracc. Filadelfia, C.P.35010                                                                                          

Gómez Palacio, Durango, México


Rodríguez-López, Bruno                                                                                                                                 

Facultad de Ciencias Biológicas                                                                                                                

Universidad Juárez del Estado de Durango                                                                                                         

Av. Universidad s/n. Fracc. Filadelfia, C.P.35010                                                                                          

Gómez Palacio, Durango, México


Instituto de Biotecnología                                                                                                                             

Universidad Nacional Autónoma de México                                                                                                

Avenida Universidad 2001, Chamilpa, C.P. 62210                                                                                 

Cuernavaca, Morelos, México


Department of Biological Sciences                                                                                                               

Clemson University                                                                                                                                     

Clemson, South Carolina USA


Department of Integrative Biology                                                                                                             

University of South Florida                                                                                                                                    

Tampa, Florida, USA


Strickland, Jason

Department of Biology                                                                                                                      

University of South Alabama                                                                                                                       

Mobile, Alabama USA


The Black-tailed Rattlesnake (Crotalus molossus) complex has been shown to exhibit venom variation both among and within its lineages. However, the molecular mechanisms driving this variation remain poorly understood. In this study, we generated genomes, venom gland transcriptomes, and the venom proteomes from representative juvenile and adult individuals across five lineages of the Crotalus molossus complex. We aimed to assess how the repertoire of toxin genes and their expression levels contribute to differences in the composition and abundance of venom toxins. All five lineages exhibited differences in the number of toxin genes, with Crotalus m. molossus displaying the highest number and Crotalus m. oaxacus the lowest. We found that both highly and lowly expressed toxin transcripts were differentially expressed in individuals with varying snout-vent lengths (SVL) across the five lineages. However, the number of toxin transcripts differentially expressed differed among lineages. In C. basiliscus and C. m. oaxacus, all individuals except one per lineage showed a significant relationship between the abundance of toxin families at both the transcript and protein levels. In C. m. molossus and C. ornatus, a correlation between abundance of transcripts and proteins was detected in all cases. In C. m. nigrescens, four out of the ten individuals were shown to display a correlation. These findings suggest that both the diversity of toxin genes and their differential expression contribute to the interspecific and ontogenetic venom variation within the Crotalus molossus complex.

 
 
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