ABSTRACT
We report that eight heterozygous missense mutations in TUBB3, encoding the neuron-specific beta-tubulin isotype III, result in a spectrum of human nervous system disorders that we now call the TUBB3 syndromes. Each mutation causes the ocular motility disorder CFEOM3, whereas some also result in intellectual and behavioral impairments, facial paralysis, and/or later-onset axonal sensorimotor polyneuropathy. Neuroimaging reveals a spectrum of abnormalities including hypoplasia of oculomotor nerves and dysgenesis of the corpus callosum, anterior commissure, and corticospinal tracts. A knock-in disease mouse model reveals axon guidance defects without evidence of cortical cell migration abnormalities. We show that the disease-associated mutations can impair tubulin heterodimer formation in vitro, although folded mutant heterodimers can still polymerize into microtubules. Modeling each mutation in yeast tubulin demonstrates that all alter dynamic instability whereas a subset disrupts the interaction of microtubules with kinesin motors. These findings demonstrate that normal TUBB3 is required for axon guidance and maintenance in mammals.
Subject(s)
Tubulin/metabolism , Amino Acid Sequence , Animals , Axons/metabolism , Brain/embryology , Brain/metabolism , Cell Survival , Child , Developmental Disabilities , Female , Humans , Kinesins/metabolism , Male , Mice , Mice, Inbred C57BL , Microtubules/metabolism , Models, Molecular , Molecular Sequence Data , Mutation, Missense , Protein Transport , Tubulin/chemistry , Tubulin/geneticsABSTRACT
Vertebrate cellular immunity displays substantial variation among taxa and environments. Hematological parameters such as white blood-cell counts have emerged as a valuable tool to understand this variation by assessing the immunological status of individuals. These tools have long revealed that vertebrate cellular immune systems are highly plastic and respond to injury and infection. However, cellular immune systems may also be able to anticipate a high risk of injury from environmental cues (e.g., predation-related cues) and respond plastically ahead of time. We studied white blood-cell (leukocyte) profiles in African cichlids Pelvicachromis taeniatus that were raised for 4 years under different levels of perceived predation risk. In a split-clutch design, we raised fish from hatching onwards under chronic exposure to either conspecific alarm cues (communicating high predation risk) or a distilled water control treatment. Differential blood analysis revealed that alarm cue-exposed fish had twice as many lymphocytes in peripheral blood as did controls, a condition called lymphocytosis. The presence of a higher number of lymphocytes makes the cellular immune response more potent, which accelerates the removal of invading foreign antigens from the bloodstream, and, therefore, may be putatively beneficial in the face of injury. This observed lymphocytosis after long-term exposure to conspecific alarm cues constitutes first evidence for an anticipatory and adaptive plastic response of the cellular immune system to future immunological challenges.
Subject(s)
Cichlids , Lymphocytosis , Animals , Cues , Humans , Immune System , Plastics , Predatory BehaviorABSTRACT
A 39-year old patient with gastric adenocarcinoma stage IV failed to respond to preoperative chemotherapies containing 5-FU and cisplatin as well as 5-FU and irinotecan. After third-line chemotherapy with two cycles of docetaxel and cisplatin we confirmed a clinical partial response. A complete histologically confirmed remission was detected after complete resection of the tumor. Following two postoperative cycles of docetaxel and cisplatin, the tumor is still in complete remission after more than eight years.