Efficiency of Spermatogonial Dedifferentiation during Aging

Wong, Chihunt; Jones, D. Leanne

doi:10.1371/journal.pone.0033635

Cited by 12 publications

(12 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Alternatively, a continuous increase in EGF signaling (blue line in Figure 7) may promote a continuous progression of the cysts towards terminal differentiation, thereby gradually reducing stem cell characteristics and increasing differentiation competence. The view that spermatogonia may retain stem cell characteristics is consistent with the observation that they can revert into GSCs when exposed to Unpaired, the ligand activating the JAK/STAT pathway [70]–[72].…”

Section: Discussionsupporting

confidence: 79%

A Temporal Signature of Epidermal Growth Factor Signaling Regulates the Differentiation of Germline Cells in Testes of Drosophila melanogaster

et al. 2013

View full text Add to dashboard Cite

Tissue replenishment from stem cells follows a precise cascade of events, during which stem cell daughters first proliferate by mitotic transit amplifying divisions and then enter terminal differentiation. Here we address how stem cell daughters are guided through the early steps of development. In Drosophila testes, somatic cyst cells enclose the proliferating and differentiating germline cells and the units of germline and surrounding cyst cells are commonly referred to as cysts. By characterizing flies with reduced or increased Epidermal Growth Factor (EGF) signaling we show that EGF triggers different responses in the cysts dependent on its dose. In addition to the previously reported requirement for EGF signaling in cyst formation, a low dose of EGF signaling is required for the progression of the germline cells through transit amplifying divisions, and a high dose of EGF signaling promotes terminal differentiation. Terminal differentiation was promoted in testes expressing a constitutively active EGF Receptor (EGFR) and in testes expressing both a secreted EGF and the EGFR in the cyst cells, but not in testes expressing either only EGF or only EGFR. We propose that as the cysts develop, a temporal signature of EGF signaling is created by the coordinated increase of both the production of active ligands by the germline cells and the amount of available receptor molecules on the cyst cells.

show abstract

Section: Discussionsupporting

confidence: 79%

A Temporal Signature of Epidermal Growth Factor Signaling Regulates the Differentiation of Germline Cells in Testes of Drosophila melanogaster

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Dedifferentiation of spermatogonia occurs in wild type testes over the life of the fly, and as flies age, GSCs resulting from dedifferentiation events accumulate in greater numbers in the niche 60 . Additionally, under conditions where STAT function is conditionally removed and then restored, dedifferentiation has been shown to occur with comparable efficiency in both young and old flies, indicating that an aging niche is capable of supporting robust dedifferentiation 76 . Exposure to X-irradiation triggers a dramatic increase in dedifferentiation, but starving and refeeding flies, which leads to loss and then regaining of GSCs, does not trigger dedifferentiation 32 , 33 , 60 .…”

Section: Aging and Stress-related Changes To Gscs And Their Nichementioning

confidence: 99%

Recent advances in Drosophila male germline stem cell biology

2012

View full text Add to dashboard Cite

The ability of stem cells to divide asymmetrically to produce both self-renewing and differentiating daughter cells sustains many adult tissues, but germline stem cells (GSCs) are unique among stem cells as they perpetuate the genome of the species. The cellular and molecular mechanisms regulating most mammalian stem cells in their endogenous local microenvironments, or niches, are quite challenging to study. However, studies of stem cell niches such as those found in the Drosophila gonads have proven very useful. In these tissues, GSCs are housed in a readily identifiable niche, and the ability to genetically manipulate these cells and their neighbors has uncovered several fundamental mechanisms that are relevant to stem cells more generally. Here, we summarize recent work on the regulation of GSCs in the Drosophila testis niche by intercellular signals, and on the intracellular mechanisms that cooperate with these signals to ensure the survival of the germline. This review focuses on GSCs within the adult Drosophila testis; somatic stem cells in this tissue are reviewed by Zoller and Schulz in this issue.1 For a review of the testis niche as a whole, see de Cuevas and Matunis,2 and for more comprehensive reviews of the Drosophila testis, refer to Fuller3 and Davies and Fuller.4

show abstract

“…Compared to sperm from young flies, sperm from old flies will have spent more time in the early stages of spermatogenesis (as germline stem cells and spermatogonia) (Wallenfang et al 2006;Wong and Jones 2012). Because HR-h appears to be more commonly used in the early stages of spermatogenesis (Chan et al 2011), sperm from old flies are more likely to have experienced a DSB at a spermatogenic stage where repair by HR-h is more frequent.…”

Section: Possible Causes Of Condition-dependent Dna Repairmentioning

confidence: 99%

DNA Repair Pathway Choice Is Influenced by the Health of Drosophila melanogaster

Wang

Agrawal

2012

Genetics

View full text Add to dashboard Cite

In nature, individuals vary tremendously in condition and this may be an important source of variation in mutation rate. Condition is likely to affect cell state and thereby impact the amount of DNA damage sustained and/or the way it is repaired. Here, we focus on DNA repair. If low-condition individuals are less capable of devoting the same level of resources to accurate repair, they may suffer higher mutation rates. However, repair decisions are also governed by various aspects of cell physiology, which may render the prediction that "higher-condition individuals use better repair mechanisms" too simplistic. We use a larval diet manipulation in Drosophila melanogaster to create high-and low-condition individuals and then contrast their relative usage of three repair pathways [homologous recombination (HR), single-strand annealing (SSA), and nonhomologous end joining (NHEJ)] that differ in their mechanistic requirements and their mutational consequences. We find that low-condition flies are more likely than high-condition flies to use the most conservative of these three repair pathways, suggesting that physiological constraints on repair pathway usage may be more important than energetic costs. We also show that the repair differences between high-and low-condition flies resemble those between young and old flies, suggesting the underlying mechanisms may be similar. Finally, we observe that the effect of larval diet on adult repair increases as flies age, indicating that developmental differences early in life can have long-lasting consequences.

show abstract

Efficiency of Spermatogonial Dedifferentiation during Aging

Cited by 12 publications

References 45 publications

A Temporal Signature of Epidermal Growth Factor Signaling Regulates the Differentiation of Germline Cells in Testes of Drosophila melanogaster

A Temporal Signature of Epidermal Growth Factor Signaling Regulates the Differentiation of Germline Cells in Testes of Drosophila melanogaster

Recent advances in Drosophila male germline stem cell biology

DNA Repair Pathway Choice Is Influenced by the Health of Drosophila melanogaster

Contact Info

Product

Resources

About