code: def addReagentTargetedGene(
              self, reagent_id, gene_id, targeted_gene_id=None,
              targeted_gene_label=None, description=None):
          
  
          # akin to a variant locus
          if targeted_gene_id is None:
              targeted_gene_id = '_' + gene_id + '-' + reagent_id
              targeted_gene_id = targeted_gene_id.replace(":", "")
          self.model.addIndividualToGraph(
              targeted_gene_id, targeted_gene_label,
  
              self.globaltt['reagent_targeted_gene'], description)
  
          if gene_id is not None:
              self.graph.addTriple(
                  targeted_gene_id, self.globaltt['is_expression_variant_of'],
                  gene_id)
  
          self.graph.addTriple(
              targeted_gene_id, self.globaltt['is_targeted_by'], reagent_id)
  
          return
docs: This will create the instance of a gene that is targeted by a molecular
          reagent (such as a morpholino or rnai).
          If an instance id is not supplied,
          we will create it as an anonymous individual which is of the type
          GENO:reagent_targeted_gene.
          We will also add the targets relationship between the reagent and
          gene class.
  
          <targeted_gene_id> a GENO:reagent_targeted_gene
          rdf:label targeted_gene_label
          dc:description description
          <reagent_id> GENO:targets_gene <gene_id>
  
          :param reagent_id:
          :param gene_id:
          :param targeted_gene_id:
          :return: