Genes with Animation

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)
		d3.json("data.json", function(err, mydata) {
      var group = d3.select("svg").selectAll("g")
      	.data(mydata)
      	.enter()
      	.append("g")
      	
        group.transition()
        		.duration(1000)
        
				group.append("rect")
      	.attr ("stroke-width", 4)
      	.attr("stroke", "black")
      	.attr("y", function (d) {
        	if (d.orientation == "forward") {
            return 100;
          }
        	else if (d.orientation == "reverse") {
            return 125;
          }
      })
      	.attr("height",35)
      	.attr("x", function (d) {
        	return d.start;
      	})
      	.attr("width", function (d) {
        	return d.stop - d.start;
      	})
      	.attr("fill", function(d) {
        	if (d.orientation == "forward") {
          	return "#40fcc0";  
          }
        	else if (d.orientation == "reverse") {
            return "#40d3fc";
          }
        })  
      
        group.append("text")
        	.text(function(d){return d.name})
        	.attr("y", function (d) {
        	if (d.orientation == "forward") {
            return 125;
           }
        else return 150})
        	.attr("x", function (d) {
        	return d.start + 5
      	})
         .attr ("font-family", "impact")
         .attr ("fill", "white")
         .attr ("font-size", "18px")
        
        
    });
    		
    		
  </script>
</body>

https://d3js.org/d3.v4.min.js