Introduction to Cells, DNA, and Viruses
Patricia G. Melloy in Viruses and Society, 2023
Cellular macromolecules are organized into compartments called organelles (like little organs) that have an organization allowing for the work of the cell to happen. So, like organs such as the heart and lungs that have a special role in the body, organelles have a special role inside the cell. Some examples of key cellular organelles include the nucleus (where DNA is housed), mitochondria (energy generation), and ribosomes (protein production). Except for the nucleolus residing in the nucleus, organelles are found in what is known as the cytoplasm or cytosol of the eukaryotic cell. The nucleus is an important organelle because it acts as the central control point for all the activities of the cell. The nucleus houses most of the cell’s DNA in the form of protein/DNA structures known as chromosomes that allow for condensation of the large amount of genetic material in each cell (Alberts et al. 2019). Cell division occurs in a process known as mitosis, in which the chromosomes are copied and separated equally between the two daughter cells. Later, we will talk about organelles that help move or traffic things around the cell, as well as into and out of the cell. Trafficking-related organelles include the endoplasmic reticulum, Golgi apparatus, and vesicles. Viruses can exploit the cellular trafficking network to move into and out of the cell.
Genetics in neonatal surgical practice
Prem Puri in Newborn Surgery, 2017
The M phase itself comprises a number of stages—prophase, metaphase, anaphase, telophase, and cytokinesis—and involves interplay between the chromosomes and specialized tubulin-based microtubules. The mitotic spindle is composed of microtubules and microtubule-associated proteins. In metaphase, the condensed chromatids line up along the equatorial plane of a cell. In anaphase, spindle tubules extend from the centrioles located at each pole of the cells to the chromosomal centromeres. As these tubules move back toward the centriole, they pull one chromatid with them to opposite poles of the cell. The splitting of the centromere and separation of sister chromatids toward two poles is termed anaphase. By the telophase, the chromatids have reached opposite poles of the dividing cell. The nuclear membrane starts to reform, completing mitosis, and the cytoplasm also divides. Cell division is completed by cytokinesis, during which the parent cell completely divides into two identical daughter cells.
Cancer Biology and Genetics for Non-Biologists
Trevor F. Cox in Medical Statistics for Cancer Studies, 2022
Cells take in raw ingredients, process them and output products. Oxygen and nutrients from food have to be inputted, the nutrients are metabolised with the help of oxygen and energy is released to be used by the cell. Each type of cell has a function, so for example, acini cells in a saliva gland produce saliva as output. Cells do not act alone and they combine together to form body tissue. Cells die and are replaced by new cells generated by cell division (mitosis). About 60 billion of your cells die each day and luckily about 60 billion new cells are created each day. That's of your cells each day. Different types of cells have different lifetimes; red blood cells last about 120 days, pancreas cells about one year, cells in your eye lens last as long as you do. The process of cell death is termed apoptosis. The human body is made up almost entirely of proteins – apart from the water and fat. Proteins are abundant in cells. The set of human proteins is called the proteome, which consists of tens of thousands of proteins.
Toxicity of Persian Gulf shell-less marine mollusc (Peronia peronii) methanolic extract on melanoma tumor mitochondria
Published in Cutaneous and Ocular Toxicology, 2023
Yalda Arast, Aida Jabbarzadeh, Farahnaz Tanbakosazan, Abdollah Arjmand, Amir. Vazirizadeh, Jalal Pourahmad
In advanced countries, cancer is one of the most important causes of death. Cell division happens regularly in tissues as part of a normal cell cycle. To have normal tissue is necessary to strike a precise balance between the two main process of proliferation and apoptosis [1,2]. The mortality rate is dramatically expanded, even though the frequency of malignant Melanoma is minor than %0.8 per 100 000 people. In fact, over the past 60 years, the overall mortality rate from MM in China has risen steadily at a 6.5% annual rate. The most lethal skin cancer, Melanoma, relies heavily on the acute activity of mitochondria and ROS for its persistence. Recent studies have shown that healthy tissue has consistent mitochondrial morphology, tissue, and protein expression, whereas this pattern is not seen in skin cancer [3,4]. Due to the vast oceans that cover two-thirds of the planet, the dominant ecosystem on the Earth is the marine ecosystem, which is home to about half of biodiversity [5]. In compounds extracted from marine origins, bioactive properties with various activities have been observed, such as anti-tumour, anti-cancer, anti-microtubule, anti-proliferative, anti-hypertensive, cytotoxic, and antibiotic properties. These substances have a variety of chemical properties, including phenol, alkaloids, terpenoids, polyesters, and other secondary metabolites present in sponges, bacteria, dinoflagellate, and seaweed [6–8].
Implications of cell division cycle associated 4 on the Wilm’s tumor cells viability via AKT/mTOR signaling pathway
Published in Renal Failure, 2021
Suqing Li, Cong Qin, Yike Chen, Dan Wei, Zhijun Tan, Jiadong Meng
Cell division plays a vital role in the life process. Numerous studies have revealed that any malfunction in the process of cell division could lead to malignant tumors [7–9]. Cell division cycle associated protein 4 (CDCA4) is a member of the CDCA family, which is co-expressed with known cell cycle genes including Cyclin, CDC2, CDC7, and others [10]. It has been proven to play a unique role in regulating cell cycle and is associated with transition of G1/S phase [11]. Furthermore, it has been reported that CDCA4 regulates the p53-dependent transcriptional activity and plays a vital role in transcriptional regulation and cell fate determination through JUN oncogene [12]. Therefore, further study of the functions of the members of CDCA family, including CDCA4, and understanding their role in tumorigenesis may provide new ideas for preventing tumor progression. In addition, CDCA4 was reported to enhance proliferation and reduce apoptosis in human breast carcinoma cells [13]. Besides, the expression of CDCA4 was observed to be over-expressed in human ovarian carcinoma tissues by comparison with the non-tumor counterparts [14]. However, its role in Wilm’s tumor is still not fully elucidated.
MOS mutation causes female infertility with large polar body oocytes
Published in Gynecological Endocrinology, 2022
Guangzhong Jiao, Huayu Lian, Jinhao Xing, Lili Chen, Zhaoli Du, Xiaoyan Liu
Proper oocyte maturation is essential for subsequent fertilization and early embryonic development, which is necessary for successful reproduction [1]. We can evaluate the morphology of human oocytes with the help of assisted reproductive technology [2]. Maturation of oocytes requires two meiosis. During meiosis, bipolar meiotic spindles form and homologous chromosomes are arranged through microtubule-organizing centers (MTOCs) [3–5]. After the spindle is assembled, with the extrusion of the first polar body, the oocyte extrudes half of its genetic material and then goes directly into the metaphase II (MII); the oocyte arrests at MII until fertilization [6, 7]. Unlike the symmetric cell division that occurs in mitosis, mammalian oocyte meiosis is characterized by asymmetric division, producing a highly polarized and large metaphase II-arrested oocyte and a small polar body [8]. The failure of asymmetric oocyte division results in the production of large polar bodies in oocytes, usually due to low oocyte quality or aging after ovulation [9]. In mice, some studies have identified abnormal gene expression leading to a meiotic spindle dysfunction phenotype; however, the genetic etiology of human oocytes remains largely unknown.
Related Knowledge Centers
- Eukaryote
- Ploidy
- Cell Cycle
- Mitosis
- Cell Nucleus
- Gamete
- Meiosis
- Chromosome
- Cell
- Haploidisation