J. Richard McIntosh
J. Richard McIntosh is a Distinguished Professor Emeritus in Molecular, Cellular, and Developmental Biology at the University of Colorado Boulder.
[4] McIntosh's research career looks at a variety of things, including different parts of mitosis, microtubules, and motor proteins.
[7] This technology is best suited to observe extremely complex structures and can image thinner sections of samples than can be physically made to study.
[7] One of McIntosh’s earlier studies in the field of cell biology is in 1974, where his team published a paper on the structures of flagella of Pyrsonympha, an organism found in termites.
[9] McIntosh’s team uses basal bodies and HeLa cells to study how protofilaments ‘hook’ onto them—either in right-handedness or left-handedness—in vitro to determine polarity.
[10] It was noted that measuring the tubulin addition in interphase was difficult due to the lack of structures, while it was more observable in a mitotic cell.
Kinesin, a motor protein found to move around vesicles in the cell, was recently discovered on another paper published the same year.
Kinesin, a motor protein found to move around vesicles in the cell, was recently discovered on another paper published the same year.
[13] With IMOD, researchers can study tomographies and data from both electron and light microscopes, and create three-dimensional images to interact with.
[13] A few years later in 1999, McIntosh’s team published a study using cryofixing and electron tomography to create a 3-dimensional model of the Golgi apparatus.
[14] In 2002, McIntosh’s team continued his earlier interests in “Chromosome-microtubule interactions during mitosis.” [15] This review paper explains how spindle microtubules bind to chromosomes during segregation at places called kinetochores and the description of the Kinetochore-Dependent Checkpoint.
[15] Some of the motor proteins mentioned in the article include those associated with the kinetochore at the plus or minus end or those that help with the disassembly of microtubules.
[16] In this work, these scientists helped create a naming structure for kinesin proteins, that are involved in transport in the cell along with microtubules.
[17] Here, the researchers applied these findings to chromosome segregation and concluded that the microtubule dynamics create the forces needed during mitosis.
[18] McIntosh’s letter “Motors or dynamics: What really moves chromosomes?” to Nature cell biology in 2012 explains an overview of the different directions his lab has taken so far.
[19] In those who study how chromosomes move during the process of mitosis, researchers argue either that microtubules generate the forces needed to separate them or that certain motor proteins do.
[19] When McIntosh first started his research, he noted he was very confident in the motor protein school of thought and related it to the sliding filament theory used to explain muscle contraction.
[19] However, by reading other research group’s papers and conducting other studies that found adenosine triphosphate (ATP) and the motor protein dynein were not necessary for chromosome movement, he started to consider the influence that microtubules had in this process.
[20] It was observed overall that microtubule depolymerization and the movement of motor proteins are very fast, but the chromosomes move slowly during their separation in the anaphase A stage of mitosis.
[20] It was also noted that separation of different protofilaments over individual tubulin dimers may be another influence in the depolymerization and subsequent chromosome movement in mitosis.
[21] Continuing using the electron tomography technique, in 2020 McIntosh and his team used this visualization strategy to observe how different kinds of microtubules work together during the metaphase state of mitosis.
[24] This collection of review articles helps readers get an overview of mitosis, a process that McIntosh believes is essential to life itself.
[4] This book, influenced by his son’s death to lung cancer, discusses every stage of the process: screening, diagnosing, and treating.
[2] In this text, McIntosh discusses science-heavy topics related to cancer such as the role of oncogenes, tumor suppressors, and the immune system.
