public partial class Form1 : Form
    {
        List<SomeClass> list_ = new List<SomeClass>();
        public Form2()
        {
            InitializeComponent();
        }

        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }
        private void Form2_Load(object sender, EventArgs e)
        {
            list_.Add(new SomeClass());
            bindingSource1.DataSource = list_;
            bindingSource2.DataSource = list_;
            dataGridView1.DataSource = bindingSource1;
            dataGridView2.DataSource = bindingSource2;
        }
    }
    public class SomeClass
    {
        public event EventHandler nameChanged;
        void OnnameChanged(string value)
        {
            EventHandler d = nameChanged;
            if (d != null)
                d(this, new EventArgs());
        }
        public event EventHandler descriptionChanged;
        void OndescriptionChanged(string value)
        {
            EventHandler d = descriptionChanged;
            if (d != null)
                d(this, new EventArgs());
        }
        string _name;
        string _des;
        public string name
        {
            set
            {
                if (string.Compare(_name, value, StringComparison.OrdinalIgnoreCase) != 0)
                {
                    _name = value;
                    OnnameChanged(_name);
                }
            }
            get { return _name; }
        }
        public string description
        {
            set
            {
                if (string.Compare(_des, value, StringComparison.OrdinalIgnoreCase) != 0)
                {
                    _des = value;
                    OndescriptionChanged(_des);
                }
            }
            get { return _des; }
        }

        public SomeClass()
        {
            name = "testName";
            description = "testDescription";
        }
    }

        private void Form1_Load(object sender, EventArgs e)
        {
            list_.Add(new SomeClass());
....

namespace WindowsFormsApplication1
{
    
    public partial class Form1 : Form
    {
        BindingList<SomeClass> _list = new BindingList<SomeClass>();
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            bindingSource1.DataSource = _list;
            bindingSource2.DataSource = _list;
            dataGridView1.DataSource = bindingSource1;
            dataGridView2.DataSource = bindingSource2;
        }
    }
    public class SomeClass : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        void FirePropertyChangedNotification(string propName)
        {
            PropertyChangedEventHandler d = PropertyChanged;
            if (d != null)
                d(this, new PropertyChangedEventArgs(propName));
        }
        string _name;
        string _des;
        public string name
        {
            set
            {
                _name = value;
                FirePropertyChangedNotification("name");
            }
            get { return _name; }
        }
        public string description
        {
            set
            {
                _des = value;
                FirePropertyChangedNotification("description");
            }
            get { return _des; }
        }

        public SomeClass()
        {
            name = "testName";
            description = "testDescription";
        }
    }
}