Stem Cells Signal to the Niche through the Notch Pathway in the Drosophila Ovary

Ward, Ellen J.; Shcherbata, Halyna R.; Reynolds, Steven H.; Fischer, Karin A.; Hatfield, Steven; Ruohola‐Baker, Hannele

doi:10.1016/j.cub.2006.10.022

Cited by 133 publications

(163 citation statements)

References 40 publications

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“…The most notable ones are quail (LOC410324), which is involved in actin filament-dependent apoptosis in nurse cells in the Drosophila ovary (Matova et al 1999); cabut (LOC410326), which is an ecdysteroid-responsive transcriptional activator associated with cell death, germband shortening, and the JNK cascade (Munoz-Descalzo et al 2005;Zhao et al 2008); delta (LOC410351), which affects notch signaling and has been reported to influence the number of germline stem cells in the Drosophila ovary (Ward et al 2006); and miro (LOC725244), which is involved in mitochondrial homeostasis, apoptotic signal transduction and cytoskeleton organization (Fransson et al 2003). In addition, several other genes could also be involved in determining ovariole number (Table S1).…”

Section: Results Of Initial Ahb and Ehb Surveymentioning

confidence: 99%

“…It is expressed almost ubiquitously during embryonic development and has the highest levels of adult expression in the hindgut and ovary. Overexpression of delta in the germline results in extra germline stem cells (Ward et al 2006), which could be responsible for extra ovarioles. Cabut was selected as another top candidate because it is expressed in the pole plasm early in development, it is responsive to endocrine stimuli (Zhao et al 2008), and it is connected to cellular apoptosis via the JNK pathway (Mazars et al 2001).…”

Section: Discussionmentioning

confidence: 99%

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The Genetic Basis of Transgressive Ovary Size in Honeybee Workers

et al. 2009

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Ovarioles are the functional unit of the female insect reproductive organs and the number of ovarioles per ovary strongly influences egg-laying rate and fecundity. Social evolution in the honeybee (Apis mellifera) has resulted in queens with 200-360 total ovarioles and workers with usually 20 or less. In addition, variation in ovariole number among workers relates to worker sensory tuning, foraging behavior, and the ability to lay unfertilized male-destined eggs. To study the genetic architecture of worker ovariole number, we performed a series of crosses between Africanized and European bees that differ in worker ovariole number. Unexpectedly, these crosses produced transgressive worker phenotypes with extreme ovariole numbers that were sensitive to the social environment. We used a new selective pooled DNA interval mapping approach with two Africanized backcrosses to identify quantitative trait loci (QTL) underlying the transgressive ovary phenotype. We identified one QTL on chromosome 11 and found some evidence for another QTL on chromosome 2. Both QTL regions contain plausible functional candidate genes. The ovariole number of foragers was correlated with the sugar concentration of collected nectar, supporting previous studies showing a link between worker physiology and foraging behavior. We discuss how the phenotype of extreme worker ovariole numbers and the underlying genetic factors we identified could be linked to the development of queen traits.T HE number of ovariole filaments per ovary is an important female reproductive character that affects fecundity across insect taxa (Richard et al. 2005;Makert et al. 2006). Social insect lineages have evolved a strong dimorphism in ovariole number between reproductive and nonreproductive castes. For example, while most families of bees consistently have 6 total ovarioles, and most species in the family Apidae have 8, the highly social species in the genus Apis (the honeybees) have queens that can have .360 total ovarioles and workers that often have ,10 (Winston 1987;Michener 2003). This queen-worker dimorphism is of primary importance because it translates into differential reproductive potential that defines the social roles of these female castes (Winston 1987) and classifies social species in general (Sherman et al. 1995). Furthermore, ovary size (i.e., ovariole number) is the most sensitive indicator of caste-specific development in honeybees (Dedej et al. 1998). The extreme increase in ovariole number for queen honeybees enables high egg-laying rates (.1500 per day) and is apparently a result of selection for increased colony reproduction (growth and fission by swarming) (Seeley 1997). Honeybee queens are thus highly specialized for egg laying, similar to queens of several other social insect taxa, such as army ants or higher termites (Hö lldobler and Wilson 1990). Honeybee workers in contrast, do not normally reproduce but perform all other essential activities including foraging for nectar, pollen, and water; caring for brood; and building, main...

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Section: Results Of Initial Ahb and Ehb Surveymentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The Genetic Basis of Transgressive Ovary Size in Honeybee Workers

et al. 2009

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“…In each germarium, GSCs are anchored to the cap cells through adherens junctions (Xie & Spradling, 2000;Song et al ., 2002). Cap cells provide the stem cell niche, as they are both necessary and sufficient for GSC self-renewal (Ward et al ., 2006;Song et al ., 2007) (Fig. 1a).…”

Section: Introductionmentioning

confidence: 99%

Age‐related changes of germline stem cell activity, niche signaling activity and egg production in Drosophila

et al. 2008

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SummaryAdult stem cells are important in replenishing aged cells to maintain tissue homeostasis. Aging in turn may exert profound effects on stem cell's regenerative potential, but to date the mechanisms of such stem cell aging are poorly understood, and it is not clear to what extent stem cell aging contributes to tissue or organ aging. Here we show in female Drosophila that germline stem cell (GSC) division rate progressively declines with age, which is accompanied by reduced decapentaplegic ( dpp ) niche signaling pathway activation within GSCs. Egg production also rapidly declines with age, which is accompanied by both decreased stem cell division and increased incidence of cell death of developing eggs, especially in the oldest females. Genetically increasing dpp expression delays GSC activity decline and transiently increases egg production. We conclude that age-related decline of reproduction is caused by both decreased GSC activity and increased incidence of cell death during oogenesis, while decreased GSC activity is attributed to declined signaling from the regulatory niche. We suggest that niche functional decay may be an important mechanism for stem cell aging and system failure.

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“…Recent work has shown that ectopic expression of activated Notch within somatic cells results in a marked increase in the number of cap cells (7,8). The increased number of cap cells subsequently leads to an expansion of the GSC population.…”

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confidence: 99%

Loss of lysine-specific demethylase 1 nonautonomously causes stem cell tumors in the Drosophila ovary

Eliazer

Shalaby

2011

Proc. Natl. Acad. Sci. U.S.A.

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Specialized microenvironments called niches keep stem cells in an undifferentiated and self-renewing state. Dedicated stromal cells form niches by producing a variety of factors that act directly on stem cells. The size and signaling output of niches must be finely tuned to ensure proper tissue homeostasis. Although advances have been made in identifying factors that promote niche cell fate, the mechanisms that restrict niche cell formation during development and limit niche signaling output in adults remain poorly understood. Here, we show that the histone lysine-specific demethylase 1 (Lsd1) regulates the size of the germline stem cell (GSC) niche in Drosophila ovaries. GSC maintenance depends on bone morphogenetic protein (BMP) signals produced by a small cluster of cap cells located at the anterior tip of the germarium. Lsd1 null mutant ovaries carry small germline tumors containing an expanded number of GSC-like cells with round fusomes that display ectopic BMP signal responsiveness away from the normal niche. Clonal analysis and cell type-specific rescue experiments demonstrate that Lsd1 functions within the escort cells (ECs) that reside immediately adjacent to cap cells and prevents them from ectopically producing niche-specific signals. Temporally restricted gene knockdown experiments suggest that Lsd1 functions both during development, to specify EC fate, and in adulthood, to prevent ECs from forming ectopic niches independent of changes in cell fate. Further analysis shows that Lsd1 functions to repress decapentaplegic (dpp) expression in adult germaria. The role of Lsd1 in regulating niche-specific signals may have important implications for understanding how disruption of its mammalian homolog contributes to cancer and metastasis.

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Stem Cells Signal to the Niche through the Notch Pathway in the Drosophila Ovary

Cited by 133 publications

References 40 publications

The Genetic Basis of Transgressive Ovary Size in Honeybee Workers

The Genetic Basis of Transgressive Ovary Size in Honeybee Workers

Age‐related changes of germline stem cell activity, niche signaling activity and egg production in Drosophila

Loss of lysine-specific demethylase 1 nonautonomously causes stem cell tumors in the Drosophila ovary

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