BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250801T011453EDT-1605Ofj3UK@132.216.98.100 DTSTAMP:20250801T051453Z DESCRIPTION:4 O'Clock Forum continues this year's seminar series with a tal k by Dr. Edgar Demesa-Arevalo\, Post Doctoral Fellow\, Cold Spring Harbor \n\nFood security represent a big challenge nowadays\, due to the dramatic increase of population and climate change the land extensions destined to produce crops has been reduced and increasing crops yields is one alterna tive to solve this problem. Maize is one of the most important crops world wide and has been used not only as an agronomic model but also as a genomi c\, physiological\, genetic and developmental model. To increase seed prod uction in corn\, we need to understand the molecular basis behind this pro cess. The seeds are nurtured in the female inflorescence\, once the female flowers are pollinated. Inflorescence development is tightly regulated\, and variation in cob shapes can be explained by alterations in regulatory circuits of meristem maintenance. The core mechanism is highly conserved a cross species. However\, the particularities of each plant have evolved va riations to guarantee the proper function of  inflorescence meristems. CLE peptides are the signaling molecules perceived in the stem cell niche to establish a balance between proliferation and differentiation. In Arabidop sis\, CLAVATA3 (CLV3) is the main peptide involved in this process\, while its ortholog in maize was not clear. Using a novel multi-guide RNA (gRNA) CRISPR/Cas9 approach we generate mutations in two closer orthologs to CLV 3 in maize and other eight maize CLE peptides (ZmCLEs) expressed in merist ems. By molecular functional characterization\, we found ZmCLE7 is the ort holog to CLV3\, and the lack of this is partially compensated by a second CLE peptide: ZmFCP1. ZmCLE7 mutants showed meristem fasciation or over pro liferation\, a trait that\, potentially\, can be fine-tuned to increase th e space to bear seeds. We are currently characterizing additional ZmCLE mu tants\, trying to identify if these compensation mechanisms are regulating other meristematic entities in corn. Additionally\, we are targeting othe r gene families that might be involve in suppressing meristem determinacy\ ; we can generate quadruple mutants using our multi-guide arrays. The  stu dy of meristem regulation has allowed us to discover and shape new agronom ical traits that can contribute to increase crop yield in cereals.\n\nABOU T THE SPEAKER:\n\nDr. Edgar Demesa-Arevalo started his scientific training doing his BSc thesis in the Center for Research and Advanced Studies of t he National Polytechnic Institute (CINVESTAV-IPN) in Mexico City\, trying to understand the establishment of symbiotic mycorrhizas. He did his Ph.D. in CINVESTAV campus Irapuato (México) under the mentorship of Jean-Philip pe Vielle-Calzada\, identifying the nature of the signals involved in the vegetative to reproductive phase in Arabidopsis. Later\, he joined Dave Ja ckson’s Lab in Cold Spring Harbor Laboratory (USA)\, focusing his research on two main topics\, the establishment of transgenic lines as a resource for maize community and investigating the molecular mechanisms involved in meristem regulation in maize. He also optimized a multiple-sgRNA array fo r CRISPR/Cas9 in maize\, widely used in maize community nowadays.\n DTSTART:20191121T210000Z DTEND:20191121T210000Z LOCATION:R3-048\, Raymond Building\, CA\, QC\, St Anne de Bellevue\, H9X 3V 9\, 21111 Lakeshore Road SUMMARY:4 O'Clock Forum: Unveiling genetic redundancy mechanisms in develop mental regulatory circuits by genome edition in maize URL:/macdonald/channels/event/4-oclock-forum-unveiling -genetic-redundancy-mechanisms-developmental-regulatory-circuits-genome-30 2636 END:VEVENT END:VCALENDAR