2011 Annual Science Report
Massachusetts Institute of Technology Reporting | SEP 2010 – AUG 2011
Evolution and Development of Sensory and Nervous Systems in the Basal Branches of the Animal Tree
Animals interact with the world through complex sensory structures (eyes, ears, antennas, etc.), which are coordinated by collections of neurons. While the nervous and sensory systems of animals are incredibly diverse, a growing body of evidence suggests that many of these systems are controlled by similar sets of genes. We are looking at early branching and understudied lineages of the animal family tree (using the jellyfish Aurelia and the worm Neanthes respectively) to see if these animals use similar genes during neurosensory development as the better-studied fruit fly and mouse. This research is critical for determining which structures are shared between animals because of common ancestry (known as homologous structures) and those that evolved independently in different lineages. Ultimately, such research informs how morphologically and behaviorally complex animals evolve.
During the period we have advanced our work on the evolution of sensory structures in basal animals in a number of ways, including studies of gene expression and new efforts in genomics. Chris Winchell finished his PhD, and of the many postdoctoral opportunities he was offered, he took a position with Nipam Patel’s lab in Berkeley. An undergraduate researcher in the lab, Andy Navarette an underrepresented minority, has now gone on to do PhD work in developmental genetics and evolution also at Berkeley. A paper from Chris’ NAI funded PhD work, on developmental gene expression and the interplay between sensory organs and appendages, was published during the period. A second paper on the expression of the LIM Homeodoman genes Apterous and LIM1, which together play a critical role in the specification of the neural architecture, is being prepared for publication in Evolution and Development. We are also developing new methods for phylogenetic analysis of protein-coding sequences suitable to the gene tree analyses, such as the POU (neural differentiation) gene data we have assembled form across the Metazoa.
Our work on the sensory organization of the jellyfish Aurelia is advancing. During this period, David Gold received the opportunity to attend the Embryology course at the Marine Biological Laboratory in Woods Hole. There he was able to interact with other NAI group members, including Nicole King and Roger Summons, while pursuing novel developmental techniques in Aurelia. Additionally, we have been using high-throughput 454 sequencing to begin building an Aurelia proteome EST database, focusing on the developing sensory structures. We have initiated a collaboration with Rob Steele of UC Irvine and Ralph Greenspan of UC San Diego to sequence the genome of the species of Aurelia that we have actively worked on in the lab. Development of these genomic resources is a critical step in advancing the study of the evolution of neural and sensory organization in animals, as Aurelia will provide a tractable model organism that retains sensory structures. Other cnidarians are either difficult to study or, as is the case with Hydra and Nematostella models, lack the sensory structures often associated with the motile medusa stage. Outreach efforts include engaging high school students in research both in the laboratory at UCLA and at the Cabrillo Aquarium, educating multiple UCLA undergraduates in the lab, and instruction in a general education class for non-science majors entitled Evolution of the Cosmos, Earth and Life which integrates a range of astrobiology themes.
PROJECT INVESTIGATORS:David Jacobs
Project InvestigatorDavid Gold
PROJECT MEMBERS:Nicole King
RELATED OBJECTIVES:Objective 4.1
Earth's early biosphere.
Production of complex life.