Biology subjects

Nanes Sarfati, D.

Publications and source records attributed to Nanes Sarfati, D..

3 recordsLinked to original sources

bioRxiv2026

Aiptasia larvae are phenotypically validated as a model of coral bleaching using high-throughput machine-learning image analysis

The sea anemone Aiptasia is a model system for understanding cnidarian loss of symbiotic algae under heat stress (bleaching). While Aiptasia polyps have been widely used to study this process, accurate symbiosis phenotyping grapples with discordant length scales: fine spatial resolution (~100 um) is needed across a whole organism (~5 mm). To address this, we consider small (~100 um), optically transparent Aiptasia larvae as a bleaching model suitable for whole-organism phenotyping by fluorescence microscopy with larvae classified as symbiotic when algae are localized within gastrodermal cells. To expedite phenotyping, we introduce a machine-learning (ML) image-analysis pipeline (SYMPHONY) designed for single-larva resolution analysis of intact larvae. SYMPHONY efficiently identifies the cellular location of internalized algae (accuracy: 79%, precision: 82%, recall: 79%, F1 score: 79%; training dataset composed of 1611 total objects). Additionally, SYMPHONY reports statistically significant larval bleaching under heat stress and corroborates manual phenotyping results, while significantly reducing operator labor from hours to minutes. The combination of the Aiptasia larvae model and the SYMPHONY pipeline aims to accelerate our understanding of symbiosis breakdown.

bioengineering↗

bioRxiv2023

Coordinated wound responses in a regenerative animal-algal photosymbiotic metaorganism

Animal regeneration requires coordinated responses of many cell types throughout the animal body. In animals carrying endosymbionts, cells from the other species may also participate in regeneration, but how cellular responses are integrated across species is yet to be unraveled. Here, we study the acoel Convolutriloba longifissura, which hosts symbiotic Tetraselmis green algae and can regenerate entire bodies from small tissue fragments. We show that animal injury leads to a decline in the photosynthetic efficiency of the symbiotic algae and concurrently induces upregulation of a cohort of photosynthesis-related genes. A deeply conserved animal transcription factor, runt, is induced after injury and required for the acoel regeneration. Knockdown of runt also dampens algal transcriptional responses to the host injury, particularly in photosynthesis related pathways, and results in further reduction of photosynthetic efficiency post-injury. Our results suggest that the runt-dependent animal regeneration program coordinates wound responses across the symbiotic partners and regulates photosynthetic carbon assimilation in this metaorganism.

developmental biology↗

bioRxiv2020

Single-cell analysis of Schistosoma mansoni reveals a conserved genetic program controlling germline stem cell fate

Schistosomes are parasitic flatworms causing one of the most prevalent infectious diseases from which millions of people are currently suffering. Their germline outputs many fertilized eggs, which are both the transmissible agents and the cause of the infection-associated pathology. Given its significance, the schistosome germline has been a research focus for more than a century. Nonetheless, little is known about the molecular mechanisms that regulate its development. Here, we construct a transcriptomic cell type atlas of juvenile schistosomes. This allows us to capture germline stem cells (GSCs) during de novo gonadal development. We identify a genetic program that balances the fate of GSC between proliferation and differentiation. This program is controlled by onecut, a homeobox transcription factor, and boule, an mRNA binding protein. Evaluating this genetic program in schistosomes free-living evolutionary cousin, the planarian, shows that this germline-specific regulatory program is conserved but its function has changed significantly during evolution.

developmental biology↗