TY - JOUR
T1 - Microtubule dynamics and organization during hyphal growth and branching in Neurospora crassa
AU - Mouriño-Pérez, Rosa R.
AU - Roberson, Robert
AU - Bartnicki-García, Salomon
N1 - Funding Information:
We to thank Silvia L. Ramos-García for laboratory assistance. This work was supported by Grant for Basic Science Research Projects from Consejo Nacional de Ciencia y Tecnología (SEP-2003-CO2-44724).
PY - 2006/6
Y1 - 2006/6
N2 - By confocal microscopy, we analyzed microtubule (Mt) behavior during hyphal growth and branching in a Neurospora crassa strain whose Mts had been tagged with GFP. Images were assembled spatially and temporally to better understand the 3-D organization of the microtubular cytoskeleton and a clearer view of its dynamics. Cytoplasmic Mts were mainly arranged longitudinally along the hyphal tube. Straight segments were rare; most Mts showed a distinct helical curvature with a long pitch and a tendency to intertwine with one another to form a loosely braided network throughout the cytoplasm. This study revealed that the microtubular cytoskeleton of a hypha advances as a unit, i.e., as the cell elongates, it moves forward by bulk flow. Nuclei appeared trapped in the microtubular network and were carried forward in unison as the hypha elongated. During branching, one or more cortical Mts became associated with the incipient branch and were pulled into the emergence of the branch. As extension of the branch and distortion of the Mts continued, Mts soon were severed with both new Mt ends (+ and -) present in the new branch. Although the exact mechanisms for addition Mt recruitment into the branch remains an open question, the recorded evidence indicates both bulk insertion of established cortical parent-hypha Mts as well as in situ polymerization were involved. The latter conclusion was supported by FRAP studies showing evidence of Mt nucleation and polymerization assembly in the growing tip of the developing branch. Nuclei entered the branch entrapped in the advancing network of Mts.
AB - By confocal microscopy, we analyzed microtubule (Mt) behavior during hyphal growth and branching in a Neurospora crassa strain whose Mts had been tagged with GFP. Images were assembled spatially and temporally to better understand the 3-D organization of the microtubular cytoskeleton and a clearer view of its dynamics. Cytoplasmic Mts were mainly arranged longitudinally along the hyphal tube. Straight segments were rare; most Mts showed a distinct helical curvature with a long pitch and a tendency to intertwine with one another to form a loosely braided network throughout the cytoplasm. This study revealed that the microtubular cytoskeleton of a hypha advances as a unit, i.e., as the cell elongates, it moves forward by bulk flow. Nuclei appeared trapped in the microtubular network and were carried forward in unison as the hypha elongated. During branching, one or more cortical Mts became associated with the incipient branch and were pulled into the emergence of the branch. As extension of the branch and distortion of the Mts continued, Mts soon were severed with both new Mt ends (+ and -) present in the new branch. Although the exact mechanisms for addition Mt recruitment into the branch remains an open question, the recorded evidence indicates both bulk insertion of established cortical parent-hypha Mts as well as in situ polymerization were involved. The latter conclusion was supported by FRAP studies showing evidence of Mt nucleation and polymerization assembly in the growing tip of the developing branch. Nuclei entered the branch entrapped in the advancing network of Mts.
KW - Branching
KW - GFP-tubulin
KW - Microtubule dynamics
KW - Neurospora crassa
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U2 - 10.1016/j.fgb.2005.10.007
DO - 10.1016/j.fgb.2005.10.007
M3 - Article
C2 - 16621627
AN - SCOPUS:33646494603
SN - 1087-1845
VL - 43
SP - 389
EP - 400
JO - Fungal Genetics and Biology
JF - Fungal Genetics and Biology
IS - 6
ER -