Ultrastructural changes in the gastrodermal phagocytic cells of the planarian Dugesia gonocephala s.l. during food digestion (Plathelminthes)

Garcia-Corrales, P.; Gamo, J.

doi:10.1007/bf00539786

Cited by 16 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By contrast, we have formally demonstrated that enterocytes do not divide in uninjured, recently fed, or injured planarians, but rather, that neoblasts differentiate into intestinal cells under these conditions. Our results are consistent with the fact that mitotic cells have not been reported in ultrastructural studies of the planarian intestine (Bowen et al, 1974b; Garcia-Corrales and Gamo, 1988; Ishii, 1965). Furthermore, with few exceptions, planarian genes expressed by neoblasts are not expressed in the intestine (Eisenhoffer et al, 2008; Guo et al, 2006; Palakodeti et al, 2008; Reddien et al, 2005; Rossi et al, 2006; Rossi et al, 2007; Rouhana et al, 2010; Salvetti et al, 2000; Salvetti et al, 2005; Shibata et al, 1999; Solana et al, 2009).…”

Section: Discussionsupporting

confidence: 93%

“…The intestine is responsible for digestion of ingested food; its highly branched morphology is thought to facilitate body-wide distribution of metabolites, serving part of the role that vasculature serves in higher organisms (Brøndsted, 1969). Cells of the intestinal epithelium, or gastrodermis, are organized into a single columnar layer surrounded by a basal lamina and enteric muscles (Bueno et al, 1997; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Kobayashi et al, 1998; Orii et al, 2002). Histological analyses suggest the existence of only two intestinal cell types – absorptive phagocytes that engulf food particles for intracellular digestion, and secretory goblet cells that release digestive enzymes into the lumen (Bowen, 1980; Bowen et al, 1974; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Ishii, 1965).…”

Section: Introductionmentioning

confidence: 99%

“…Cells of the intestinal epithelium, or gastrodermis, are organized into a single columnar layer surrounded by a basal lamina and enteric muscles (Bueno et al, 1997; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Kobayashi et al, 1998; Orii et al, 2002). Histological analyses suggest the existence of only two intestinal cell types – absorptive phagocytes that engulf food particles for intracellular digestion, and secretory goblet cells that release digestive enzymes into the lumen (Bowen, 1980; Bowen et al, 1974; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Ishii, 1965). Decades of ultrastructural and physiological studies have characterized the role of these cells during digestion and nutrient storage (Bowen, 1980; Bowen et al, 1974; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Ishii, 1965).…”

Section: Introductionmentioning

confidence: 99%

“…Histological analyses suggest the existence of only two intestinal cell types – absorptive phagocytes that engulf food particles for intracellular digestion, and secretory goblet cells that release digestive enzymes into the lumen (Bowen, 1980; Bowen et al, 1974; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Ishii, 1965). Decades of ultrastructural and physiological studies have characterized the role of these cells during digestion and nutrient storage (Bowen, 1980; Bowen et al, 1974; Garcia-Corrales and Gamo, 1986; Garcia-Corrales and Gamo, 1988; Ishii, 1965). However, in contrast to other organs such as the central nervous system (Cebrià, 2007), and aside from several studies of axial polarity (Adell et al, 2009; Cebrià et al, 2007; Gurley et al, 2010; Gurley et al, 2008; Iglesias et al, 2008; Nogi and Levin, 2005; Oviedo et al, 2010), the intestine has received limited attention during developmental studies of growth and regeneration.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stem cell-based growth, regeneration, and remodeling of the planarian intestine

Forsthoefel

Park

Newmark

2011

Developmental Biology

120

142

View full text Add to dashboard Cite

Although some animals are capable of regenerating organs, the mechanisms by which this is achieved are poorly understood. In planarians, pluripotent somatic stem cells called neoblasts supply new cells for growth, replenish tissues in response to cellular turnover, and regenerate tissues after injury. For most tissues and organs, however, the spatiotemporal dynamics of stem cell differentiation and the fate of tissue that existed prior to injury have not been characterized systematically. Utilizing in vivo imaging and bromodeoxyuridine pulse-chase experiments, we have analyzed growth and regeneration of the planarian intestine, the organ responsible for digestion and nutrient distribution. During growth, we observe that new gut branches are added along the entire anteroposterior axis. We find that new enterocytes differentiate throughout the intestine rather than in specific growth zones, suggesting that branching morphogenesis is achieved primarily by remodeling of differentiated intestinal tissues. During regeneration, we also demonstrate a previously unappreciated degree of intestinal remodeling, in which pre-existing posterior gut tissue contributes extensively to the newly formed anterior gut, and vice versa. By contrast to growing animals, differentiation of new intestinal cells occurs at preferential locations, including within newly generated tissue (the blastema), and along pre-existing intestinal branches undergoing remodeling. Our results indicate that growth and regeneration of the planarian intestine are achieved by coordinated differentiation of stem cells and the remodeling of pre-existing tissues. Elucidation of the mechanisms by which these processes are integrated will be critical for understanding organogenesis in a post-embryonic context.

show abstract

Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Stem cell-based growth, regeneration, and remodeling of the planarian intestine

Forsthoefel

Park

Newmark

2011

Developmental Biology

120

142

View full text Add to dashboard Cite

show abstract

“…As a “blind” gut, food enters the intestine and waste is excreted through a centrally located, muscular pharynx (Figure 1A) (Hyman, 1951). Two intestinal cell types have been identified histologically: absorptive phagocytic enterocytes that engulf food particles for intracellular digestion, and secretory goblet or “gland” cells that release enzymes (Ishii, 1965; Garcia-Corrales and Gamo, 1986, 1988). …”

Section: Resultsmentioning

confidence: 99%

An RNAi Screen Reveals Intestinal Regulators of Branching Morphogenesis, Differentiation, and Stem Cell Proliferation in Planarians

et al. 2012

View full text Add to dashboard Cite

SUMMARY Planarians grow and regenerate organs by coordinating proliferation and differentiation of pluripotent stem cells with remodeling of post-mitotic tissues. Understanding how these processes are orchestrated requires characterizing cell type-specific gene expression programs and their regulation during regeneration and homeostasis. To this end, we analyzed the expression profile of planarian intestinal phagocytes, cells responsible for digestion and nutrient storage/distribution. Utilizing RNA interference, we identified cytoskeletal regulators required for intestinal branching morphogenesis, and a modulator of bioactive sphingolipid metabolism, ceramide synthase, required for the production of functional phagocytes. Additionally, we found that a gut-enriched homeobox transcription factor, nkx-2.2, is required for somatic stem cell proliferation, suggesting a niche-like role for phagocytes. Identification of evolutionarily conserved regulators of intestinal branching, differentiation, and stem cell dynamics demonstrates the utility of the planarian digestive system as a model for elucidating the mechanisms controlling post-embryonic organogenesis.

show abstract

Gradual specialization of phagocytic ameboid cells may have impaired regenerative capacities in metazoan lineages

Lima

Abrahão

Pentagna

et al. 2022

Developmental Dynamics

View full text Add to dashboard Cite

Animal regeneration is a fascinating field of research that has captured the attention of many generations of scientists. Among the cellular mechanisms underlying tissue and organ regeneration, we highlight the role of phagocytic ameboid cells (PACs). Beyond their ability to engulf nutritional particles, microbes, and apoptotic cells, their involvement in regeneration has been widely documented. It has been extensively described that, at least in part, animal regenerative mechanisms rely on PACs that serve as a hub for a range of critical physiological functions, both in health and disease. Considering the phylogenetics of PAC evolution, and the loss and gain of nutritional, immunological, and regenerative potential across Metazoa, we aim to discuss when and how phagocytic activity was first co‐opted to regenerative tissue repair. We propose that the gradual specialization of PACs during metazoan derivation may have contributed to the loss of regenerative potential in animals, with critical impacts on potential translational strategies for regenerative medicine.

show abstract

Ultrastructural changes in the gastrodermal phagocytic cells of the planarian Dugesia gonocephala s.l. during food digestion (Plathelminthes)

Cited by 16 publications

References 15 publications

Stem cell-based growth, regeneration, and remodeling of the planarian intestine

Stem cell-based growth, regeneration, and remodeling of the planarian intestine

An RNAi Screen Reveals Intestinal Regulators of Branching Morphogenesis, Differentiation, and Stem Cell Proliferation in Planarians

Gradual specialization of phagocytic ameboid cells may have impaired regenerative capacities in metazoan lineages

Contact Info

Product

Resources

About