Diet and adiposity are linked to fertility, yet the mechanisms remain largely unknown. Our previous studies showed that Drosophila germline stem cells (GSCs) and their progeny divide and grow faster on yeast-rich than -poor diets, and the insulin and Target of Rapamycin (TOR) nutrient-sensing pathways act within the ovary for this response. These studies, however, did not address the mechanisms whereby nutrient sensing by adipocytes impacts the ovary. Mammalian adipocyte signals control much of our physiology, including ovarian function. The Drosophila fat body, composed of adipocytes and hepatocyte-like cells, also has an endocrine role. In larvae, nutrient-dependent secreted fat body factors affect organismal growth; how the adult fat body modulates oogenesis is less well studied. Our data show that adipocyte-specific disruption of amino acid transport, TOR or insulin signaling cause distinct ovarian phenotypes. Reduced adipocyte amino acid transport lowers GSC numbers and impairs ovulation. Low adipocyte TOR signaling causes an ovulation defect, but GSCs are unaffected, suggesting that adipocyte amino acid sensing controls early germ cells independently of TOR. In contrast to effects of TOR, low adipocyte insulin signaling reduces the numbers of cap cells (major niche components) and GSCs, and impairs vitellogenesis. We propose that distinct nutrient-dependent mechanisms operate within adipocytes to modulate specific secreted factors that control different stages of oogenesis, thereby refining the ovarian response to diet. To test this hypothesis, we will (1) determine how adipocyte insulin signaling controls niche size, GSC number, and vitellogenesis; and (2) identify the mechanisms whereby amino acid levels within adipocytes control GSC numbers and ovulation. Relevance: Obesity is prevalent in the western world, and results in the abnormal function of fat cells, which in turn can lead to infertility. We propose to take advantage of powerful research tools in fruit flies to investigate the normal role of fat cells in controlling ovarian function. Because of the high degree of evolutionary conservation of molecules and biological processes between fruit flies and humans, this work will likely provide valuable insights into how to treat obesity-related infertility or design new contraceptives.

Public Health Relevance

Obesity is prevalent in the western world, and results in the abnormal function of fat cells, which in turn can lead to infertility. We propose to take advantage of powerful research tools in fruit flies to investigate the normal role of fat cells in controllin ovarian function. Because of the high degree of evolutionary conservation of molecules and biological processes between fruit flies and humans, this work will likely provide valuable insights into how to treat obesity-related infertility or design new contraceptives.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM069875-12
Application #
9102232
Study Section
Cellular, Molecular and Integrative Reproduction Study Section (CMIR)
Program Officer
Melillo, Amanda A
Project Start
2005-05-01
Project End
2018-06-30
Budget Start
2016-07-01
Budget End
2017-06-30
Support Year
12
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Biochemistry
Type
Schools of Public Health
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21205
Armstrong, Alissa R; Drummond-Barbosa, Daniela (2018) Insulin signaling acts in adult adipocytes via GSK-3? and independently of FOXO to control Drosophila female germline stem cell numbers. Dev Biol 440:31-39
Weaver, Lesley N; Drummond-Barbosa, Daniela (2018) Maintenance of Proper Germline Stem Cell Number Requires Adipocyte Collagen in Adult Drosophila Females. Genetics 209:1155-1166
Laws, Kaitlin M; Drummond-Barbosa, Daniela (2017) Control of Germline Stem Cell Lineages by Diet and Physiology. Results Probl Cell Differ 59:67-99
Hsu, Hwei-Jan; Drummond-Barbosa, Daniela (2017) A visual screen for diet-regulated proteins in the Drosophila ovary using GFP protein trap lines. Gene Expr Patterns 23-24:13-21
Ha, Yang; Arnold, Anna R; Nuñez, Nicole N et al. (2017) Sulfur K-Edge XAS Studies of the Effect of DNA Binding on the [Fe4S4] Site in EndoIII and MutY. J Am Chem Soc 139:11434-11442
Matsuoka, Shinya; Armstrong, Alissa R; Sampson, Leesa L et al. (2017) Adipocyte Metabolic Pathways Regulated by Diet Control the Female Germline Stem Cell Lineage in Drosophila melanogaster. Genetics 206:953-971
Ables, Elizabeth T; Drummond-Barbosa, Daniela (2017) Steroid Hormones and the Physiological Regulation of Tissue-Resident Stem Cells: Lessons from the Drosophila Ovary. Curr Stem Cell Rep 3:9-18
Laws, Kaitlin M; Drummond-Barbosa, Daniela (2016) AMP-activated protein kinase has diet-dependent and -independent roles in Drosophila oogenesis. Dev Biol 420:90-99
Ables, Elizabeth T; Hwang, Grace H; Finger, Danielle S et al. (2016) A Genetic Mosaic Screen Reveals Ecdysone-Responsive Genes Regulating Drosophila Oogenesis. G3 (Bethesda) 6:2629-42
Weaver, Lesley N; Drummond-Barbosa, Daniela (2015) Gut healing: haemocytes aid via Sax and Tkv jazzes it down. Nat Cell Biol 17:707-9

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