Control of Germline Stem Cell Lineages by Diet and Physiology

Abstract

Tight coupling of reproduction to environmental factors and physiological status is key to long-term species survival. In particular, highly conserved pathways modulate germline stem cell lineages according to nutrient availability. This Chapter focuses on recent in vivo studies in genetic model organisms that shed light on how diet-dependent signals control the proliferation, maintenance, and survival of adult germline stem cells and their progeny. These signaling pathways can operate intrinsically in the germline, modulate the niche, or act through intermediate organs to influence stem cells and their differentiating progeny. In addition to illustrating the extent of dietary regulation of reproduction, findings from these studies have implications for fertility during aging or disease states.

Linking the environment, DAF-7/TGFβ signaling and LAG-2/DSL ligand expression in the germline stem cell niche

“…In addition to direct signals from the stem cell niche, global signals reporting environmental and physiological conditions can influence the outcome of stem cell decisions (Drummond-Barbosa, 2008;Hubbard et al, 2012;Laws and Drummond-Barbosa, 2017). However, our understanding of the mechanisms underlying this regulation remains incomplete.…”

Escort-like somatic cells mediate early mouse fetal ovarian development but surface-derived Lgr5+ cells support primordial follicles

“…Wave one follicles develop faster than wave two follicles, do not enter quiescence, and rapidly embark as primary follicles on an accelerated maturation program to allow fertility onset by the time of puberty. The rate of follicle development in several organisms can be strongly modulated by nutrition as reflected in insulin signaling (Laws and Drummond-Barbosa, 2017), and mammalian follicular growth is also influenced by activin/inhibin and steroid signaling (Myers et al 2009;Ojima et al 2019).…”

Steroid Hormones and the Physiological Regulation of Tissue-Resident Stem Cells: Lessons from the Drosophila Ovary

“…Female GSCs give rise to the cellular precursors for Drosophila oocytes [13, 14]. GSCs are housed in a structure called the germarium (Fig.…”

“…GSCs reside in a somatic niche composed of terminal filament cells, cap cells, and a subset of escort cells (Fig 1A). The niche produces bone morphogenetic protein (BMP) signals that are necessary for GSC self-renewal [14]. GSCs are physically attached to cap cells via E-cadherin and divide asymmetrically to create a posteriorly displaced cystoblast, the daughter cell destined for differentiation, while retaining the other daughter as a GSC in the niche.…”

“…Drosophila female GSCs therefore remain one of the best models for the study of stem cell function and regulation at the single cell level in vivo . In particular, definitive evidence that stem cells are controlled by multiple endocrine factors, including steroid hormones, tied to the physiological status of the organism was obtained in the Drosophila GSC system [14]. …”