Access constructors from datacontract in wcf to client application

[ServiceContract]
    public interface IService1
    {

    }

    [DataContract]
    public class CLSReportMenu
    {
        int _reportID = 0;
        string _reportName = string.Empty;

        int _parentID = 0;

        [DataMember]
        public int ReportID
        {
            get { return _reportID; }
            set { _reportID = value; }
        }

        [DataMember]
        public string ReportName
        {
            get { return _reportName; }
            set { _reportName = value; }
        }

        [DataMember]
        public int ParentID
        {
            get { return _parentID; }
            set { _parentID = value; }
        }

        public CLSReportMenu(string reportname)
        {
            ReportName = reportname;
        }

    }

    [DataContract]
    public class ReportHierarchy
    {
        public ReportHierarchy()
        {
        }

        [DataMember]
        public DataTable ReportRecord
        {
            get;
            set;
        }

        [DataMember]
        public CLSReportMenu objreport { get; set; }
        [DataMember]
        public List<ReportHierarchy> Children { get; set; }

        public ReportHierarchy(CLSReportMenu report)
        {
            objreport = report;
            Children = new List<ReportHierarchy>();
        }

    }