ASBT mRNA expression localization observed in the ileum is in which compartments?

ASBT mRNA expression localization observed in the ileum is in which compartments?

• A. Nucleus only
• B. Both nucleus and cytoplasm
• C. Cytoplasm only
• D. Mitochondria

Answer: (B)

The main concept is that nuclear-encoded mRNA is present in both the nucleus and the cytoplasm because transcription and processing happen in the nucleus while translation occurs in the cytoplasm. For ASBT mRNA in ileal enterocytes, you’d detect transcripts at the sites of transcription inside the nucleus and the mature mRNA in the cytoplasm ready for translation into the transporter protein. Mitochondria are not the site for this nuclear-encoded mRNA, so localization there isn’t expected. Therefore, observing ASBT mRNA in both compartments reflects the normal mRNA lifecycle: transcription in the nucleus and translation in the cytoplasm.

The main concept is that nuclear-encoded mRNA is present in both the nucleus and the cytoplasm because transcription and processing happen in the nucleus while translation occurs in the cytoplasm. For ASBT mRNA in ileal enterocytes, you’d detect transcripts at the sites of transcription inside the nucleus and the mature mRNA in the cytoplasm ready for translation into the transporter protein. Mitochondria are not the site for this nuclear-encoded mRNA, so localization there isn’t expected. Therefore, observing ASBT mRNA in both compartments reflects the normal mRNA lifecycle: transcription in the nucleus and translation in the cytoplasm.