Display substrate and display device

A display substrate having a mounting region, a first display region adjacent to the mounting region, and a second display region surrounding the first display region and/or the mounting region, the display substrate comprising:

• a substrate;
• a driving circuit layer on the substrate and comprising a plurality of pixel driving circuits, the plurality of pixel driving circuits being in the first display region and the second display region, and an arrangement density of the pixel driving circuits in the second display region being less than an arrangement density of the pixel driving circuits in the first display region;
• a plurality of light emitting devices in the mounting region, the first display region, and the second display region, a first electrode of one of the plurality of light emitting device being electrically coupled to a corresponding one of the plurality of pixel driving circuits, and the pixel driving circuit electrically coupled to the first electrode of the light emitting device in the mounting region being located in the first display region;
• and
• a plurality of data lines, one of the plurality of pixel driving circuits being electrically coupled to one of the plurality of data lines, wherein
• the plurality of data lines comprise a first data line;
• the first data line comprises a first sub data line segment coupled to the pixel driving circuits for driving at least part of the light emitting devices in the mounting region, a second sub data line segment coupled to the pixel driving circuits for driving at least part of the light-emitting devices in the second display region, and a third sub data line segment coupled to the pixel driving circuits for driving at least part of the light-emitting devices in the first display region;
• the second sub data line segment is coupled to the third sub data line segment;
• the first sub data line segment is coupled to the second sub data line segment through a first transfer electrode;
• the first transfer electrode extends along a first direction;
• the first sub data line segment and the second sub data line segment extend approximately along a second direction;
• and
• the first direction intersects with the second direction.