NHE Jan 14 Notes
Intestine quickly doubles in size (paper looked at 1 to 3 days, but we are look at minutes to hours after feeding)
- Intestinal nutrient transporters and hydrolytic enzymes
We need to find references to specific genes that would be active in liver or intestine, especially after feeding.
- Tolozoa, Lam, and Diamond
- Karasov and Diamond
We don't know when they started the clock, but either way we are most interested in the earliest time points
Food that reaches intestine is mostly liquefied, so intestine is mostly absorption, not digestion
Amino acid absorption peaks early on in digestion. So does sugar.
- recovery for having to double mass of organs?
- transport mechanisms are produced early in digestion
- most absorption happens in anterior small intestine
Is there an increase in transcription? Or are there post-translational modification (phosphorylation for example) that increase activity. Could also be increased translation. Only factor we can detect is transcription
Find intestinal transport proteins and homologs for other species.
- Burmese python genome is transcribed
serosa layer - outer layer that cover the membrane walls Most of organ growth occurs in the brush border in the intestine. (Possible inward growth by microvilli into intestine, not doubling of outer wall.)
When organs were frozen, cold not tell distal from anterior. Do not know if only serosa was sampled. Need microvilli if want the transport proteins RNA's to be included.
Some transporters drive amino acid uptake by ion gradients (sodium dependent/independent) Ion could enter with the aa or against aa From Fig 5, mostly look like sodium independent transport
Fig 7, ions, cholesterol, protein, phosphatase, etc...all enter the blood somehow - there must be transporters
Fig 9, most of growth in mass in small intestine is in anterior
Second Paper - Review paper - Python advertisement
Phylogenic comparison Noted microvilli increase mass
Glucose transporter SGLT1
How do microvilli grow? Cell division? Cell growth?