Abstract: The invention provides methods and materials involved in displaying polypeptide sequences using viruses such as avian leukosis viruses. Specifically, the invention provides nucleic acid molecules, collections of nucleic acid molecules, polypeptides, collections of polypeptides, viruses, and collections of viruses as well as methods for making nucleic acid molecules, collections of nucleic acid molecules, polypeptides, collections of polypeptides, viruses, and collections of viruses. The invention also provides methods for obtaining displayed polypeptide sequences that interact with biological molecules and/or cells as well as methods for identifying biological molecules that interact with displayed polypeptides.

Abstract: A parallel entry tie include a flexible strap having a locking head and a free end. The strap is received in a passage in the locking head where it is engaged by a locking tab which is biased toward engagement with the strap as it passes into and through the passage. The locking tab prevents withdrawal of the tie from the locking head. The strap can be released for withdrawal from the locking head by moving the tab against the bias. An opening is provided in the locking head generally opposite to the location of the locking tab. The strap, throughout the major portion of its extension, has a width which is less than the width of the opening. The opening in the locking head is preferably provided with spaced shoulders in the area of the engagement between the locking tab and the straps serrations. An inclined lip is provided in the area through which the strap exits the locking head. The lip is angled such as to displace the strap from the normal exterior of the strap.