Problemas com o setLayout

class CadastrarGene extends JPanel {

JLabel unigeneLabel,giLabel,nomeLabel,sequenciaLabel;

JTextField unigeneTextField,giTextField,nomeTextField;

JTextArea sequenciaTextArea;

JScrollPane  sequenciaScrollPane;

public CadastrarGene( )   {
    
         setLayout (new GridLayout(4,1));
         
         
       unigeneLabel = new JLabel ("UNIGENE", JLabel.LEFT);
       giLabel = new JLabel ("GI", JLabel.LEFT);
       nomeLabel = new JLabel ("Nome do gene", JLabel.LEFT);
       sequenciaLabel = new JLabel ("Seqüência de DNA", JLabel.LEFT);
       unigeneTextField = new JTextField (10);
      giTextField = new JTextField (10);
       nomeTextField = new JTextField (255);
      sequenciaTextArea = new JTextArea (8,40);
      sequenciaScrollPane = new JScrollPane (sequenciaTextArea);
                         
     
   add(unigeneLabel);
   add(giLabel);
   add(nomeLabel);
   add(sequenciaLabel);
   add(unigeneTextField);
   add(giTextField);
   add(nomeTextField);
   add(sequenciaScrollPane);
     
     
}

public static void main (String [] args)  {
     JFrame CadastrarGene = new JFrame("Cadastrar gene");
     CadastrarGene.addWindowListener (new WindowAdapter()   {
          public void windowClosing (WindowEvent e)   {
                System.exit (0);
                
          }
     });
     


     CadastrarGene.setContentPane(new CadastrarGene ());
     CadastrarGene.setSize(400,90);
     CadastrarGene.setLocation(100,100);
     CadastrarGene.show();
}