Essential role of MARCKS in cortical actin dynamics during gastrulation movements

Myristoylated alanine-rich C kinase substrate (MARCKS) is an actin-binding, membrane-associated protein expressed during Xenopus embryogenesis. We analyzed its function in cytoskeletal regulation during gastrulation. Here, we show that blockade of its function impaired morphogenetic movements, including convergent extension. MARCKS was required for control of cell morphology, motility, adhesion, protrusive activity, and cortical actin formation in embryonic cells. We also demonstrate that the noncanonical Wnt pathway promotes the formation of lamellipodia- and filopodia-like protrusions and that MARCKS is necessary for this activity. These findings show that MARCKS regulates the cortical actin formation that is requisite for dynamic morphogenetic movements

Cholesterol accumulation in ovarian follicles causes ovulation defects in Abca1a⁻/⁻ Japanese medaka (Oryzias latipes)

ATP-binding cassette A1 (ABCA1) is a membrane protein, which exports excess cellular cholesterol to generate HDL to reduce the risk of the onset of cardiovascular diseases (CVD). In addition, ABCA1 exerts pleiotropic effects on such as inflammation, tissue repair, and cell proliferation and migration. In this study, we explored the novel physiological roles of ABCA1 using Japanese medaka (Oryzias latipes), a small teleost fish. Three Abca1 genes were found in the medaka genome. ABCA1A and ABCA1C exported cholesterol to generate nascent HDL as human ABCA1 when expressed in HEK293 cells. To investigate their physiological roles, each Abca1-deficient fish was generated using the CRISPR-Cas9 system. Abca1a−/− female medaka was found to be infertile, while Abca1b−/− and Abca1c−/− female medaka were fertile. In vitro ovarian follicle culture suggested that Abca1a deficiency causes ovulation defects. In the ovary, ABCA1A was expressed in theca cells, an outermost layer of the ovarian follicle. Total cholesterol content of Abca1a−/− ovary was significantly higher than that of the wild-type, while estrogen and progestin contents were compatible with those of the wild-type. Furthermore, cholesterol loading to the wild-type follicles caused ovulation defects. These results suggest that ABCA1A in theca cells regulates cholesterol content in the ovarian follicles and its deficiency inhibits successful ovulation through cholesterol accumulation in the ovarian follicle

High-resolution imaging of myosin motor in action by a high-speed atomic force microscope

金沢大学理学部The atomic force microscope (AFM) is a powerful tool for imaging biological molecules on a substrate, in solution. However, there is no effective time axis with AFM; commercially available AFMs require minutes to capture an image, but many interesting biological processes occur at much higher rate. Hence, what we can observe using the AFM is limited to stationary molecules, or those moving very slowly. We sought to increase markedly the scan speed of the AFM, so that in the future it can be used to study the dynamic behaviour of biomolecules. For this purpose, we have developed various devices optimised for high-speed scanning. Combining these devices has produced an AFM that can capture a 100 x 100 pixel image within 80 ms, thus generating a movie consisting of many successive images of a sample in aqueous solution. This is demonstrated by imaging myosin V molecules moving on mica, in solution

Adamantinoma of the Tibia. - Report of a Case with Findings of Ultrastructural and Immunohistochemical Studies,

A case of tibial adamantinoma in a one-year and ten-month old girl is reported. She had gait disturbance and her roentogenogram showed a well circumscribed radiolucent area in the tibia. Light microscopic examination showed the epithelial component of nests and pseudoglandular arrays in the loose fibrous connective tissue. We finally diagnsed the tumor as adamantinoma of the tibia based on roentogenographical and histological findings. Moreover, the nature of the neoplastic cells was studied by the immunohistochemical and electron microscopic methods. The adamantinoma is regarded as a unique neoplasm capable of differen - tiating into epithelial elements as well as mesenchymal ones . Detection of epithelial component is important to differentiate from similar disorders. The fibrous dysplasia- like lesion in stroma is interpreted as a part of the spectrum of mesenchymal differentiation

An Autopsy Case of Carcinosarcoma of the Esophagus

A case of carcinosarcoma, a rare polypoid tumor of the esophagus is presented. The characteristic gross and microscopic features as well as a discussion of the histogenesis of the sarcomatous elements are presented by microscopic, immunohistochemical and electron micronscopic examinations. Immunohistochemically, keratin and EMA (epithelial membrane antigen) were demonstrated in the islands of squamous cell carcinoma within the sarcomatous elements and in the carcinoma in situ at the border of normal mucosa. Vimentin, desmin, actin, myoglobin, factor VIII, S-100 protein, NSE, neuraminidase were not demonstrated in both the carcinomatous and the sarcomatous elements except for a positive reactivity to a-1-antichymotrypsin in the sarcomatous elements at part. It is suggested that the sarcomatous elements are of epithelial origin based on the facts as follows : 1 transition from overlying epithelium or carcinomatous islands to sarcomatous elements existent ; 2 some small tubules were formed within the sarcomatous elements, which showed transition into the sarcomatous elements ; and 3 a part of the sarcomatous elements revealed either positive or weak reactivity to keratin and EMA. Further, weak reactivity to keratin and EMA in the more anaplastic lesion may reflect the lack of tonofilaments and desmosomes in the ultrastructural findings

A GPI processing phospholipase A2, PGAP6, modulates Nodal signaling in embryos by shedding CRIPTO

©2016 Gun-Hee Lee et al. Originally published in Journal of Cell Biology. https://doi.org/10.1083/jcb.20160512

Physiological Markers of Motor Improvement Following Five-month Sprint Training in Young Boys

The 11th International Symposium on Adaptive Motion of Animals and Machines. Kobe University, Japan. 2023-06-06/09. Adaptive Motion of Animals and Machines Organizing Committee.Poster Session P4