Non-senescent Hydra tolerates severe disturbances in the nuclear lamina

Abstract

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra. We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra, the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra. A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans.

Ancestral role of Fat-like cadherins in planar cell polarity

“…To overcome the lethality of shFat knockdown, we tried doxycycline-dependent transcriptional activation. We cloned shFat9 hairpin into the doxycycline-inducible vector pIndGFP , described in a previous study ( Figure 4F) [30]. We were able to establish one Hydra line expressing shFat9 hairpin.…”

“…To investigate the function of HyFat, we used an RNA hairpin approach [29] . Two different hairpin-expressing plasmid constructs, shFat9 (nucleotides 12573 to 13178) and shFat4 (nucleotides 11493 to 11792) were inserted downstream of GFP under the control of an actin gene promoter that is active in all epithelial cells [30]. Transgenic Hydra were obtained by injecting plasmid DNAs into 1-4 cell stage embryos [31].…”

Dynamic interactions within the host-associated microbiota cause tumor formation in the basal metazoan Hydra

“…Total RNA was extracted from H. oligactis polyps and converted into cDNA using First Strand cDNA Synthesis Kit (ThermoFisher Scientific) according to manufacturer's instruction. Amplification was performed as previously described [83] using GoTaq qPCR Master Mix (Promega, Madison, USA) and specific oligonucleotide primers (S8 Table). Three biological replicates of healthy control H. oligactis, tumorous polyps and polyps grown from buds without tumor were analyzed with two technical replications.…”

Model systems for regeneration: Hydra

“…A number of molecular tools exist to analyse gene function in adult and regenerating animals. Stable transgenesis was established in 2006 (Wittlieb et al, 2006) allowing gene overexpression (Gee et al, 2010;Klimovich et al, 2018) as well as gene knockdown with constructs containing shRNAs (Klimovich et al, 2019). Gene knockdown can also be achieved by electroporating small interfering or small hairpin RNAs (siRNAs, shRNAs) into animals or aggregates (Watanabe et al, 2014;Klimovich et al, 2018;Vogg et al, 2019).…”