Singh Yadav, S. P. | Search bioRxiv

bioRxiv2026

Aging compromises Zebrafish caudal fin regeneration by disrupting Regenerative gene networks and Cellular metabolism

Zebrafish are widely recognized as a powerful vertebrate model for studying epimorphic regeneration due to their remarkable ability to restore complex tissues. However, regenerative efficiency declines with age, potentially due to alterations in gene regulatory networks and cellular metabolism. In the present study, we investigated the molecular and bioenergetic basis of age-associated regenerative decline by comparing young adult (<1 year) and old adult (>3 years) zebrafish during caudal fin regeneration. To further examine the contribution of mitochondrial function, mitochondrial dysfunction was experimentally induced using rotenone (20 nM), a mitochondrial Complex I inhibitor. Regenerative progression was assessed morphologically at 12hpa, 1dpa, 2dpa, 3dpa, and 7dpa, revealing a pronounced delay in fin regrowth in aged and rotenone-treated fish compared with young controls. Behavioral analysis indicated subtle but non-significant changes across experimental groups. Gene expression analysis using quantitative real-time PCR revealed age- and mitochondria-associated dysregulation of key regenerative gene families involved in developmental patterning, extracellular matrix organization, cellular signaling, and mitochondrial metabolism. Proteomic profiling further identified differential expression of proteins associated with mitochondrial bioenergetics, extracellular matrix remodeling, and signaling pathways required for blastema formation and tissue outgrowth. Ultrastructural examination by transmission electron microscopy revealed pronounced mitochondrial abnormalities, including enlarged mitochondria with fragmented or disrupted cristae, in aged and rotenone-treated regenerating tissues. Collectively, our integrative analysis establishes a mechanistic link between aging, mitochondrial dysfunction, and compromised regenerative capacity in zebrafish. The findings provide broader insights into metabolic constraints underlying age-related decline in regenerative potential in vertebrates.

developmental biology↗

bioRxiv2025

Enhancing CRISPR Education: A Plug-And-Play Framework for Teaching Gene Editing in Plant Biology

Modern molecular biology tools and technologies such as CRISPR have sped up scientific discovery. From an educational perspective, these advancements are both exciting and overwhelming. Educators shaping these future scientists face the ongoing challenge of staying compliant with the latest developments in molecular biology while finding effective ways to teach these discoveries. As the use of CRISPR gene editing technology continues to expand globally, there is an increasing need for a workforce that is both knowledgeable about its theoretical foundations and trained in its practical use. While advanced, technology-driven STEM courses have the potential to improve student retention, they are often lecture-heavy and lack intentional engagement strategies that support deeper learning. Moreover, agriculture is the second most impacted sector by this technology, yet there is a significant lack of teaching materials focused on CRISPR in plant biology. To address these gaps, we developed a framework for teaching gene editing that incorporates multiple engagement strategies beyond traditional lecture-based instruction. This framework was implemented over two semesters in an Introduction to Gene Editing course at Tennessee State University, offered to both undergraduate and graduate students enrolled in a degree in Agricultural Sciences. This manuscript outlines the various strategies used in the course including active learning, multimodal instructional approaches and experiential learning strategies that can be adopted in other classrooms to effectively teach gene editing. Survey-based results from the course indicate a measurable increase in student comfort with designing and executing CRISPR-Cas based experiments. Societal Impact StatementPlant biology lacks accessible teaching materials for CRISPR, a powerful gene-editing technology widely used to improve agriculture. We developed an engaging framework to teach CRISPR concepts to advanced undergraduates and graduate students in plant sciences, which can be readily adopted by other instructors. The approach increased self-reported confidence in students and comfort in explaining CRISPR. Since instructors often have limited time to design interactive lessons, this framework offers a ready-to-use, effective strategy that makes CRISPR more widely available in classrooms, ultimately strengthening CRISPR literacy in the future agricultural workforce.

scientific communication and education↗