The interaction between centrosomes and mitotic spindle poles is important for efficient spindle formation, orientation, and cell polarity. However, our understanding of the dynamics of this relationship and implications for tissue homeostasis remains poorly understood. Here we report that Drosophila melanogaster calmodulin (CaM) regulates the ability of the microcephaly-associated protein, abn...

Contact between telomeres and the fission yeast spindle pole body during meiotic prophase is crucial for subsequent spindle assembly, but the feature of telomeres that confers their ability to promote spindle formation remains mysterious. Here we show that while strains harbouring circular chromosomes devoid of telomere repeat tracts undergo aberrant meiosis with defective spindles, the inserti...

INTRODUCTION One of the fundamental signal processing techniques in spindle metrology is the separation of synchronous and asynchronous parts of spindle motion. While in many cases, the synchronous parts of the spindle motion are more important, there are many cases where knowledge of the asynchronous motion is desired. However, it is common that a time series describing the spindle motion is d...

In previous work [1], our group implemented a tilted-mirror interferometric sensor that can measure rotation of a hybrid rotary-linear axis as part of a 5-DOF machine tool intended for fabricating centimeter-scale parts. Attached to the shaft of the hybrid axis is a tilted mirror rotary sensor, which uses two laser interferometers to measure the orientation of a tilted 3-inch diameter mirror at...

In meiosis-I crane-fly spermatocytes 3 autosomal half-bivalents move to each pole in anaphase while the 2 sex-chromosomal univalents remain at the equator. The sex chromosomes move to opposite poles only after the autosomes reach the poles; the sex chromosomes start to move polewards about 25 min after the autosomal half-bivalents have begun to move. We irradiated portions of single autosomal s...

In eukaryotic cells, proper position of the mitotic spindle is necessary for successful cell division and development. We explored the nature of forces governing the positioning and elongation of the mitotic spindle in Schizosaccharomyces pombe. We hypothesized that astral microtubules exert mechanical force on the S. pombe spindle and thus help align the spindle with the major axis of the cell...

This paper presents a method to investigate the characteristics of a high-speed motorized spindle system. The geometric quality of high-precision parts is highly dependent on the dynamic performance of the entire machining system, which is determined by the interrelated dynamics of machine tool mechanical structure and cutting process. This performance is of great importance in advanced, high-p...

In animals, the female meiotic spindle is positioned at the egg cortex in a perpendicular orientation to facilitate the disposal of half of the chromosomes into a polar body. In Caenorhabditis elegans, the metaphase spindle lies parallel to the cortex, dynein is dispersed on the spindle, and the dynein activators ASPM-1 and LIN-5 are concentrated at spindle poles. Anaphase-promoting complex (AP...

The asymmetrically dividing yeast S. cerevisiae assembles a bipolar spindle well after establishing the future site of cell division (i.e., the bud neck) and the division axis (i.e., the mother-bud axis). A surveillance mechanism called spindle position checkpoint (SPOC) delays mitotic exit and cytokinesis until the spindle is properly positioned relative to the mother-bud axis, thereby ensurin...

INTRODUCTION During cell division, the mitotic spindle captures chromosomes and segregates them into two equal sets. The orientation and position of the mitotic spindle is important because the spindle equator becomes the plane of cell division. For instance, in a columnar cell with apical and basal polarity, if the spindle pole-to-pole axis orients along the cell’s long axis, the cell will div...