Display substrate, display panel and display apparatus

A display substrate, comprising:

• a first display region and a second display region;
• a base substrate;
• a plurality of sub-pixels arranged on the base substrate and located in the first display region, wherein the sub-pixel located in the first display region comprises a first pixel driving circuit and a first light-emitting device, and the first pixel driving circuit is electrically connected to the first light-emitting device and configured to drive the first light-emitting device to emit light, the first pixel driving circuit comprises a storage capacitor and a plurality of transistors, and the storage capacitor and the plurality of transistors comprised in the first pixel driving circuit are located in the first display region;
• and
• a plurality of sub-pixels arranged on the base substrate and located in the second display region, wherein the sub-pixel located in the second display region comprises a second pixel driving circuit and a second light-emitting device, and the second pixel driving circuit is electrically connected to the second light-emitting device and configured to drive the second light-emitting device to emit light,
• wherein a light transmittance of the first display region is greater than a light transmittance of the second display region;
• and
• wherein an area of an orthographic projection of an occupied region of a first pixel driving circuit of a sub-pixel in the first display region on the base substrate is less than an area of an orthographic projection of an occupied region of a second pixel driving circuit of a sub-pixel of a same color in the second display region on the base substrate.