In the cytoplasm, actin and myosin together play important roles in cell migration, intracellular transport, regulation of cell shape, cell division, and endocytosis. These functions are carried out by myosin as a motor that moves along actin filaments and creates a motive force. Over the past 20 years, studies have revealed that actin and myosin also function in the nucleus and regulate various nuclear events, including transcription, gene positioning, DNA repair, and DNA replication. In this review, we summarize the known nuclear functions of actin and myosin and the associated molecular mechanisms. To date, studies on nuclear actin and myosin have been limited to animal cells. The possibility that the nuclear functions of actin and myosin are conserved in other organisms, particularly in plants, will be discussed.

Encountering the monograph ‘Analysis of Mitosis’ by Dr. Bungo Wada, published in 1966 as a supplementary issue of Cytologia, inspired me to contribute an article on my experiences with tobacco BY-2 cells and their synchronization. This is because Dr. Wada and I share a recognition of the importance of living cells. My studies have followed cytological changes during mitosis, using tobacco BY-2 cells and developing methods such as high synchronization and fluorescence tagging. I believe that my studies provide revelatory information about the cytoskeleton during the cell cycle. Through this brief comparison of our studies, I would like to remind people of the contributions of Dr. Wada and that Cytologia has space for mechanistic studies.

To investigate the role of KLF6 in nasopharyngeal carcinoma (NPC) cells. NPC C666-1 cells were transfected with si-NC, si-KLF6, miR-181-5p mimics, and miR-NC. The transfection efficiency was evaluated using qRT-PCR to measure the expression of miR-181-5p and KLF6. The protein expression level of KLF6 was detected using WB assay. Cell proliferation was assessed using the CCK8 assay to determine the effect of KLF6. Flow cytometry was used to detect apoptosis and changes in the cell cycle of NPC cells after KLF6 inhibition. The targeting relationship between miR-181-5p and KLF6 was verified using dual fluorescein assay. The qRT-PCR results demonstrated successful transfection of si-NC, si-KLF6, miR-181-5p mimics, and miR-NC. Inhibition of KLF6 led to a decrease in miR-181 expression, whereas overexpression of miR-181-5p increased KLF6 expression. Furthermore, suppressing KLF6 expression resulted in inhibited proliferation of C666-1 cells and enhanced apoptosis. This led to an increase in S-phase cells and a decrease in G₂/M-phase cells. The dual luciferase results confirmed the targeted binding between miR-181-5p and KLF6. Inhibition of KLF6 suppresses NPC cell proliferation and promotes apoptosis through induction of cell cycle arrest.

In the present study, Lens culinaris Medik., a common food plant, was exposed to metal-based Zinc oxide nanoparticles (ZnO-NPs). The abnormalities caused by ZnO-NPs in germination and mitosis of L. culinaris were studied. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX) characteristic spectral analyses of the ZnO-NPs used in the study were also carried out. In addition, the effects of ZnO-NPs treatment of seeds on germination, root and shoot development, seedling vigor, tolerance, and mitosis in root tip cells were investigated. Increased ZnO-NPs concentrations reduced root length to approximately 50%, shoot length to 70%, and sapling vigor index to 45% compared to controls. Maximum tolerance was observed at ZnO-NPs concentrations of 25 and 50 ppm but tolerance gradually decreased above 50 ppm. Based on these data, it can be said that lentils tolerate low doses of ZnO-NPs, but are negatively affected by higher doses. Multiple analyses in the study showed that ZnO-NPs caused abnormalities in cell division such as C-metaphase, distorted metaphase, distorted anaphase and telophase, chromosome lagging, chromosome breakage, bridging, and micronucleus. All concentrations of ZnO-NPs caused a decrease in the mitotic index in root tip cells of L. culinaris compared to the control. The mitotic index reached the lowest level, especially at the highest concentration. The opposite situation was observed in chromosomal abnormalities; as the concentration increased, the abnormality rate increased compared to the control and reached the highest level at the highest concentration. Our results demonstrated that ZnO-NPs can be a clastogenic/genotoxic and cytotoxic agent. In conclusion, the L. culinaris cytogenetic test can be used for the genotoxicity monitoring of novel nanomaterials like ZnO-NPs, which are used in many consumer products.

Using the Allium test, the various toxicities caused by three distinct dosages (10, 50, and 100 mM) of the hazardous non-protein amino acid L-canavanine (L-CAN) were examined in this work. Indicators of toxicity included cytogenetic [micronucleus (MN) frequency, chromosomal abnormalities (Cas), mitotic index (MI)], physiological [germination percentage (GP), root number (RN), root length (RL), and fresh weight (FW)], biochemical [free proline (PR) level, malondialdehyde (MDA) level, catalase (CAT) activity, and superoxide dismutase (SOD) activity], and anatomical parameters. Four sets of Allium cepa L. bulbs were created: one for control (C) and three for treatments. For 7 days, the bulbs in the treatment groups were germinated with three different doses of L-CAN, whereas the bulbs in the C group were germinated with tap water. Consequently, at all three levels, exposure to L-CAN resulted in a reduction in every physiological parameter measured. In addition, every L-CAN dosage resulted in a rise in the frequency of MN and CAs together with a decrease in MI. L-CAN produced CAs such as notched nuclei, micronuclei accumulation, bilobulated and trilobulated nuclei with bud, C-metaphase, chromosomal stickiness, vagrant chromosome, and chromatid bridge in the root meristem cells. Through the induction of oxidative stress in the cells, L-CAN also produced toxicity. L-CAN exposure resulted in dose-related increases in the levels of free PR, MDA, CAT, and SOD in the root. L-CAN exposure induced anatomical harms such as deformations of the epidermal cells, development of micronucleus, accumulation of certain chemical substances, abnormal position of the epidermal cell nucleus, giant cell nucleus, and vacuole formation in the nucleus of the root tip meristem cells. Due to its inhibitory impact on Allium cepa L. test material, L-CAN induced comprehensive toxicity; the Allium test proved to be a valuable tool in identifying this toxicity.

Akashiwo sanguinea has a longitudinal and a transverse flagellum. The longitudinal flagellum shows unique retraction in addition to swimming undulation, whereas the transverse flagellum undulates within the girdle of the cell. However, it remains unclear how the transverse flagellum moves when the longitudinal flagellum retracts and whether it is anchored to the girdle along its entire length. To investigate these aspects, the movement of the transverse flagellum was observed using light microscopy. During undulation, the distal tip of the transverse flagellum was immobile and fixed at a position on the girdle. When the longitudinal flagellum retracted, the transverse flagellum stopped undulating and was pulled deeper into the girdle, with its distal tip pulling slightly towards the base, suggesting contraction. Occasionally, a partially detached transverse flagellum was observed, with the middle and/or distal parts detached and continuing to undulate whereas the other parts remained in the girdle. The contraction was more intense with the flagellum detached, suggesting that the transverse flagellum was fully attached to the girdle and contracted when the longitudinal flagellum retracted. A non-detergent-extracted model of the transverse flagellum demonstrated that contraction was induced by Ca²⁺ and not antagonized by Mg²⁺. Electron microscopy revealed that the flagellum contained an axoneme, a striated strand, and numerous external flagellar hairs. In conclusion, the transverse flagellum contracted when the longitudinal flagellum retracted. This contraction is caused by the shortening of the striated strand and is induced by Ca²⁺. In addition, the entire transverse flagellum was attached to the girdle.

The current study is the first report on the molecular characteristics of the rarely occurring medusa Limnocnida indica Annandale, 1912, a freshwater jellyfish. Its taxonomic description is based on morphological characteristics that may change depending on the environmental conditions. The most fascinating feature of this species is its erratic, unpredictable appearance, which shares a similar morphology and appears at different times and locations with a considerable interval between appearances. Nevertheless, it is unclear whether these appearances are the same species or not. The DNA marker of the species is one way to shed light on this uncertainty. To this end, the sequences of the mitochondrial genes COX1, 16S rRNA, and 12S rRNA were analyzed, compared, and reviewed with the sequences of other freshwater jellyfish to gain insight into the genetic diversity and evolutionary links of this organism. The COX1 gene had 660 bases with a GC content of 44.8%, the 16S rRNA gene had 612 bases with a GC content of 40.7% and the 12S rRNA gene had 422 bases and a GC content of 38.2%. The three genes under consideration have different nucleotide sequences compared to the other freshwater jellyfish investigated. The phylogenetic relationships inferred based on COX1 showed that the species L. indica has divergence from its congeneric species, while the analysis based on the 16S rRNA gene revealed that L. indica is related to the genus L. tanganjicae. In future research on the genetic diversity and species status of visually similar freshwater jellyfish that naturally occur at different times and places in the Western Ghats of India, the molecular data provided here on this species can be used as a relevant reference.

This study examines the cytological effects of chemical mutagen (EMS) treatment. Through cytological investigations across various meiotic phases, we observed that pollen mother cells (PMCs) exhibited desynaptic chromosomes, resulting in an elevated frequency of univalent at metaphase I compared to bivalents. Additionally, a notable increase in pollen sterility was observed in plants with induced desynapsis. These findings offer valuable genetic insights and highlight the potential for aneuploid production in mutation breeding programs. We conducted an analysis at a concentration of 0.4% EMS and observed a range of meiotic and post-meiotic abnormalities that significantly impacted the growth and development of the plant. Notably, we have observed a substantial reduction in normal pollen grain formation, indicating the potential for developing male sterile lines. EMS emerges as a potent mutagen, inducing significant cytological variations across various stages of PMC development. These findings offer valuable insights for plant breeders, facilitating the development of male sterile lines and enabling the manipulation of cytological variation in plant populations.

The chromosome numbers and the karyotypic characters of six species of the genus Aspidistra Ker-Gawl. from Vietnam were reported for the first time. A. clausa, A. hekouensis, A. zhangii, and A. superba own the same karyotype formulas of 2n=38=24m+2sm+12st. The karyotype of A. triradiata is formulated as 2n=38=20m+6sm+12st, while A. formosa is as 2n=36=20m+16st.

The cytological studies were undertaken for one of the endemic genera to India, i.e., Pinda P.K.Mukh. & Constance (Apiaceae). Cytological characters in the generic hierarchy of Pinda such as meiotic chromosome numberr n=11, somatic chromosome number 2n=22, and 2A asymmetric category of Stebbins classification have been observed. Chromosome number and karyomorphology of P. shrirangii Gosavi & Chandore are reported for the first time. Based on cytological characters, it was understood that Pinda is a cytologically stable genus and P. concanensis (Dalzell) P.K.Mukh. & Constance has an asymmetric karyotype, thus, it is an advanced species than P. shrirangii.

This study investigated the somatic chromosome numbers and morphometric properties of chromosomes in eight taxa belonging to the genus Tragopogon L. (Asteraceae) from Turkey. These taxa are T. buphthalmoides var. buphthalmoides (DC.) Boiss., T. buphthalmoides var. latifolius Boiss., T. coloratus C.A.Mey., T. dubius Scop., T. latifolius Boiss., T. porrifolius L., T. porrifolius subsp. longirostris (Sch. Bip.) Greuter, and T. reticulatus Boiss. & Huet. Chromosome numbers in most of the studied taxa were determined 2n=2x=12, while T. reticulatus 2n=4x=24, was determined. The genus Tragopogon is characterized by a basic chromosome number x=6. Satellites were observed in all studied taxa. Using the Stebbins classification system, taxa were categorized as class 2B or 3B. Additionally, various parameters such as chromosome length, haploid chromosome length, relative length, arm ratio, centromere states, karyotype asymmetry values, and karyotype formula were determined. The karyotype formulas of 7 of the 8 taxa included in the study (except T. dubius) were revealed by us for the first time.