add links to mRNA on gene page

templates/page.tpl.php

@@ -94,8 +94,8 @@ if (isset($node) && $node->type == "chado_feature") {
     else if ($node->feature->type_id->name == "polypeptide" && isset($node->feature->all_relationships['subject']['derives from']['mRNA'][0]->record->object_id->nid)) {
         $feat_nav = "You are viewing a polypeptide, more information available on the corresponding ".l("mRNA page", "node/".$node->feature->all_relationships['subject']['derives from']['mRNA'][0]->record->object_id->nid);
     }
-    else if ($node->feature->type_id->name == "gene" && isset($node->feature->all_relationships['object']['derives from']['mRNA'][0]->record->subject_id->nid)) {
-        $feat_nav = "You are viewing a gene, more information available on the corresponding ".l("mRNA page", "node/".$node->feature->all_relationships['object']['derives from']['mRNA'][0]->record->subject_id->nid);
+    else if ($node->feature->type_id->name == "gene" && isset($node->feature->all_relationships['object']['part of']['mRNA'][0]->record->subject_id->nid)) {
+        $feat_nav = "You are viewing a gene, more information available on the corresponding ".l("mRNA page", "node/".$node->feature->all_relationships['object']['part of']['mRNA'][0]->record->subject_id->nid);
     }
 }
 ?>