Monika Abedin

The genome of the choanoflagellate Monosiga brevicollis and the origin of metazoans

Choanoflagellates are the closest known relatives of metazoans. To discover potential molecular mechanisms underlying the evolution of metazoan multicellularity, we sequenced and analysed the genome of the unicellular choanoflagellate Monosiga brevicollis. The genome contains approximately 9,200 intron-rich genes, including a number that encode cell adhesion and signalling protein domains that are otherwise restricted to metazoans. Here we show that the physical linkages among protein domains often differ between M. brevicollis and metazoans, suggesting that abundant domain shuffling followed the separation of the choanoflagellate and metazoan lineages. The completion of the M. brevicollis genome allows us to reconstruct with increasing resolution the genomic changes that accompanied the origin of metazoans.

The Premetazoan Ancestry of Cadherins

Cadherin-mediated cell adhesion and signaling is essential for metazoan development and yet is absent from all other multicellular organisms. We found cadherin genes at numbers similar to those observed in complex metazoans in one of the closest single-celled relatives of metazoans, the choanoflagellate Monosiga brevicollis. Because the evolution of metazoans from a single-celled ancestor required novel cell adhesion and signaling mechanisms, the discovery of diverse cadherins in choanoflagellates suggests that cadherins may have contributed to metazoan origins.

Diverse evolutionary paths to cell adhesion

The morphological diversity of animals, fungi, plants, and other multicellular organisms stems from the fact that each lineage acquired multicellularity independently. A prerequisite for each origin of multicellularity was the evolution of mechanisms for stable cell-cell adhesion or attachment. Recent advances in comparative genomics and phylogenetics provide critical insights into the evolutionary foundations of cell adhesion. Reconstructing the evolution of cell junction proteins in animals and their unicellular relatives exemplifies the roles of co-option and innovation. Comparative studies of volvocine algae reveal specific molecular changes that accompanied the evolution of multicellularity in Volvox. Comparisons between animals and Dictyostelium show how commonalities and differences in the biology of unicellular ancestors influenced the evolution of adhesive mechanisms. Understanding the unicellular ancestry of cell adhesion helps illuminate the basic cell biology of multicellular development in modern organisms.

Starting and Maintaining Monosiga brevicollis Cultures

Cold Spring Harb Protoc; Nicole King, Susan L. Young, Monika Abedin, Martin Carr and Barry S.C. Leadbeater Cultures Monosiga brevicollis Starting and Maintaining Service Email Alerting click here. Receive free email alerts when new articles cite this article Categories Subject Cold Spring Harbor Protocols. Browse articles on similar topics from (882 articles) Laboratory Organisms, general (326 articles) Genetics, general (291 articles) Emerging Model Organisms (243 articles) Cell Culture (1068 articles) Cell Biology, general

Visualizing the Subcellular Localization of Actin, β-Tubulin, and DNA in Monosiga brevicollis

Cold Spring Harb Protoc; Nicole King, Susan L. Young, Monika Abedin, Martin Carr and Barry S.C. Leadbeater brevicollis Monosiga -Tubulin, and DNA in β Visualizing the Subcellular Localization of Actin, Service Email Alerting click here. Receive free email alerts when new articles cite this article Categories Subject Cold Spring Harbor Protocols. Browse articles on similar topics from (339 articles) Visualization, general (90 articles) Visualization of Proteins (70 articles) Visualization of Organelles (459 articles) Visualization (876 articles) Laboratory Organisms, general (293 articles) Labeling for Imaging (25 articles) Immunostaining Cells (91 articles) Immunostaining (72 articles) Immunohistochemistry (32 articles) Immunofluorescence (531 articles) Imaging/Microscopy, general (320 articles) Genetics, general (394 articles) Fluorescence (284 articles) Emerging Model Organisms (454 articles) Cell Imaging (1020 articles) Cell Biology, general (214 articles) Antibodies, general

Preparation of Total RNA from Monosiga brevicollis and Other Choanoflagellates

Cold Spring Harb Protoc; Nicole King, Susan L. Young, Monika Abedin, Martin Carr and Barry S.C. Leadbeater and Other Choanoflagellates Monosiga brevicollis Preparation of Total RNA from Service Email Alerting click here. Receive free email alerts when new articles cite this article Categories Subject Cold Spring Harbor Protocols. Browse articles on similar topics from (62 articles) RNA Purification (212 articles) RNA (1009 articles) Molecular Biology, general (880 articles) Laboratory Organisms, general (322 articles) Genetics, general (284 articles) Emerging Model Organisms (1037 articles) Cell Biology, general

Preparation of high-molecular-weight genomic DNA from Monosiga brevicollis and other choanoflagellates.

Cold Spring Harb Protoc; Nicole King, Susan L. Young, Monika Abedin, Martin Carr and Barry S.C. Leadbeater and Other Choanoflagellates Monosiga brevicollis Preparation of High-Molecular-Weight Genomic DNA from Service Email Alerting click here. Receive free email alerts when new articles cite this article Categories Subject Cold Spring Harbor Protocols. Browse articles on similar topics from (1011 articles) Molecular Biology, general (880 articles) Laboratory Organisms, general (71 articles) Genomic DNA (323 articles) Genetics, general (284 articles) Emerging Model Organisms (113 articles) DNA Purification (1049 articles) Cell Biology, general