An Investigation of Biophysical Variables in Stiff and Hypertropic Mutant Sporangiophores of Phycomyces Blakesleeanus

University Of Colorado At Denver-Downtown Campus, Denver CO

Investigators

Abstract

Previous research by the Principal Investigator (PI) has derived, developed, and established quantitative biophysical equations that describe expansive growth of the large cylindrical single-celled sporangiophores of Phycomyces blakesleeanus and other cells with walls, i.e. algal, fungal, and plant cells. The objective of the current research project is to obtain insight into relationships between the biophysical variables and associated biological processes that control expansive growth and growth behavior by using mutant sporangiophores that exhibit abnormal growth behavior. The research will focus on strains of stiff and hypertropic mutant sporangiophores which exhibit weak and enhanced tropic responses and growth responses, respectively. Biophysical experiments will be conducted to determine the magnitude and behavior of relevant biophysical variables for stiff and hypertropic mutant sporangiophores. The obtained results will be compared to those of wild type sporangiophores. Research conducted for the prior NSF Grant (MCB-0640542) proposes a fungal wall chemistry hypothesis which can explain the observed behavior of relevant biophysical variables during anoxia, during light and avoidance growth responses, and for different stages of sporangiophore development during steady growth. In the current research project, the fungal wall chemistry hypothesis is complemented with new theoretical findings that provide quantitative relationships between relevant biophysical variables and biological processes that are integral to expansive growth. Importantly, the fungal wall chemistry hypothesis together with these newly proposed quantitative relationships can reconcile the previously established quantitative biophysical equations for expansive growth with other previously proposed biological models for growth of algal, fungal, and plant cells. The fungal wall chemistry hypothesis and the newly proposed quantitative relationships will be used to analyze and interpret the experimental results obtained from stiff and hypertropic mutant sporangiophores and wild type sporangiophores. In the near future, the results of the proposed research and the sequencing of the genome can provide new insight into the functions of genes and their products in expansive growth and regulation of expansive growth of fungal cells. As the sporangiophores exhibit growth responses to sensory stimuli, the results can provide new insight into the functions of genes and their products in sensory transduction pathways. Broader Impacts The results of the proposed research will be integrated into two new graduate bioengineering courses that the PI introduced, developed, and teaches: Cellular Bioengineering I and II. Participating graduate students will be encouraged to teach one of the undergraduate laboratory courses so that the PI may mentor them through the course for the first semester and develop their confidence and teaching skills so that they can teach the second semester more independently. Graduate and undergraduate students, which include members of underrepresented groups, will participate in all aspects of the research project. The PI and participating students will conduct workshops for the Society of Hispanic Professional Engineers student chapter's annual outreach conference for high school and middle school students in the Denver metropolitan area.