All articles in a publication allowing updatable subscriptions contain a uniqueidentifier column named 'MSrepl_tran_version' ...

All articles in a publication allowing updatable subscriptions contain a uniqueidentifier column named 'MSrepl_tran_version' used for tracking changes to the replicated data. SQL Server adds such a column to published tables that do not have one. 

Adding a new column will:
     » Cause INSERT statements without column lists to fail.
     » Increase the size of the table. 

SQL Server will add a uniqueidentifier column to each of the following tables when the publication is created.