Autophagy (self-feeding) assists survival of starving cells by partial self-digestion, while dormancy as cysts, spores or seeds enables long-term survival. Starving amoebas construct multicellular fruiting bodies with spores and stalk cells, with many Dictyostelia still able to encyst individually like their single-celled ancestors. While autophagy mostly occurs in the somatic stalk cells, autophagy gene knock-outs in ( ) formed no spores and lacked cAMP induction of prespore gene expression. To investigate whether autophagy also prevents encystation, we knocked-out autophagy genes and in the dictyostelid , which forms both spores and cysts. We measured spore and cyst differentiation and viability in the knock-out as well as stalk and spore gene expression and its regulation by cAMP. We tested a hypothesis that spores require materials derived from autophagy in stalk cells. Sporulation requires secreted cAMP acting on receptors and intracellular cAMP acting on PKA. We compared the morphology and viability of spores developed in fruiting bodies with spores induced from single cells by stimulation with cAMP and 8Br-cAMP, a membrane-permeant PKA agonist. Loss of autophagy in reduced but did not prevent encystation. Stalk cells still differentiated but stalks were disorganised. However, no spores were formed at all  and cAMP-induced prespore gene expression was lost. spores induced by cAMP and 8Br-cAMP were smaller and rounder than spores formed multicellularly and while they were not lysed by detergent they germinated not (strain Ax2) or poorly (strain NC4), unlike spores formed in fruiting bodies. The stringent requirement of sporulation on both multicellularity and autophagy, which occurs mostly in stalk cells, suggests that stalk cells nurse the spores through autophagy. This highlights autophagy as a major cause for somatic cell evolution in early multicellularity.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7614253PMC
http://dx.doi.org/10.12688/openreseurope.14947.2DOI Listing

Publication Analysis

Top Keywords

stalk cells
28
spores
13
fruiting bodies
12
gene expression
12
spores formed
12
autophagy
11
cells
9
stalk
8
somatic stalk
8
survival starving
8

Similar Publications

Angiogenesis begins as endothelial cells migrate, forming a sprouting tip and subsequent growth-rich stalk cells. Here, we present a protocol for transcriptomic and epigenomic analyses of tip-like cells in cultured endothelial cells. We describe steps for stimulating human umbilical vein endothelial cells (HUVECs) with vascular endothelial cell growth factor (VEGF) to generate tip-like cells.

View Article and Find Full Text PDF

Spatial transcriptomic characterization of a Carnegie stage 7 human embryo.

Nat Cell Biol

January 2025

Key Laboratory of Organ Regeneration and Reconstruction, State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China.

Gastrulation marks a pivotal stage in mammalian embryonic development, establishing the three germ layers and body axis through lineage diversification and morphogenetic movements. However, studying human gastrulating embryos is challenging due to limited access to early tissues. Here we show the use of spatial transcriptomics to analyse a fully intact Carnegie stage 7 human embryo at single-cell resolution, along with immunofluorescence validations in a second embryo.

View Article and Find Full Text PDF

Antioxidant Potential of Xanthohumol in Disease Prevention: Evidence from Human and Animal Studies.

Antioxidants (Basel)

December 2024

Department of Food Biochemistry and Analysis, Poznan University of Life Sciences, Mazowiecka 48, 60-623 Poznan, Poland.

Xanthohumol (XN) is a phenolic compound found in the largest amount in the flowers of the hop plant, but also in the leaves and possibly in the stalks, which is successfully added to dietary supplements and cosmetics. XN is known as a potent antioxidant compound, which, according to current research, has the potential to prevent and inhibit the development of diseases, i.e.

View Article and Find Full Text PDF

Unlabelled: Bactofilins are a recently discovered class of cytoskeletal protein, widely implicated in subcellular organization and morphogenesis in bacteria and archaea. Several lines of evidence suggest that bactofilins polymerize into filaments using a central β-helical core domain, flanked by variable N- and C-terminal domains that may be important for scaffolding and other functions. However, a systematic exploration of the characteristics of these domains has yet to be performed.

View Article and Find Full Text PDF

Translationally controlled tumor protein (TCTP) is a well conserved and ubiquitously expressed multifunctional protein found in many organisms and is involved in many pathophysiological processes like cell proliferation, differentiation, development and cell death. The role of TCTP in anti-apoptosis and cancer metastasis makes it a promising candidate for cancer therapy. Dictyostelium discoideum, a protist, has two isoforms (TCTP1 and TCTP2, now referred to as TPT1 and TPT2) of which we have earlier elucidated TPT1.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!