measuring-crop-motility-and-food-passaging-in-drosophila

Measuring Crop Motility and Food Passaging in <em>Drosophila</em>

Most animals use the gastrointestinal (GI) tract to digest food. The movement of the ingested food in the GI tract is essential for nutrient absorption. ...

yangzhou university

Yangzhou University

The TORC1 regulator GATOR1/SEACIT controls meiotic entry and early meiotic events in yeast. However, how metabolic pathways influence meiotic progression in metazoans remains poorly understood. Here we examine the role of the TORC1 regulators GATOR1 and GATOR2 in the response to meiotic double-stranded breaks (DSB) during  oogenesis. We find that in mutants of the GATOR2 component , meiotic DSBs trigger the constitutive downregulation of TORC1 activity and a permanent arrest in oocyte growth. Conversely, in GATOR1 mutants, high TORC1 activity results in the delayed repair of meiotic DSBs and the hyperactivation of p53. Unexpectedly, we found that GATOR1 inhibits retrotransposon expression in the presence of meiotic DSBs in a pathway that functions in parallel to p53. Thus, our studies have revealed a link between oocyte metabolism, the repair of meiotic DSBs and retrotransposon expression.

The GATOR complex regulates an essential response to meiotic double-stranded breaks in .

Aging and age-related diseases occur in almost all organisms. Recently, it was discovered that the inhibition of target of rapamycin complex 1 (TORC1), a conserved complex that mediates nutrient status and cell metabolism, can extend an individual's lifespan and inhibit age-related diseases in many model organisms. However, the mechanism whereby TORC1 affects aging remains elusive. Here, we use a loss-of-function mutation in , a component of GATOR1 that mediates amino acid levels and inhibits TORC1 activity, to investigate the effect of increased TORC1 activity on the occurrence of age-related digestive dysfunction in . We found that the  mutation decreased  lifespan. Furthermore, the  mutant had a distended crop, with food accumulation at an early age. Interestingly, the inappropriate food distribution and digestion along with decreased crop contraction in  mutant can be rescued by decreasing TORC1 activity. In addition, -mutant flies exhibited age-related phenotypes in the midgut, including short gut length, a high rate of intestinal stem cell proliferation, and metabolic dysfunction, which could be rescued by inhibiting TORC1 activity. Our findings showed that the gastrointestinal tract aging process is accelerated in -mutant flies, owing to high TORC1 activity, which suggested that TORC1 promotes digestive tract senescence.

Article	Year
The GATOR complex regulates an essential response to meiotic double-stranded breaks in . eLife\| PubMed ID: 31650955	2019
The TORC1 inhibitor Nprl2 protects age-related digestive function in . Aging\| PubMed ID: 31712450	2019

Jiadong Cai

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