In essence, our body consists of two major types of cells – one group involved directly in reproducing sexually (called sex cells) and another group that are not (called somatic cells). In particular, the female sex cell is referred to as the ovum (also called egg cell) whereas the male sex cell, the sperm cell. The somatic cells, in turn, are the cells in the body that have varying functions, such as nourishing the sex cells as well as keeping the body thriving and functional.
Origin of sex cells
Our body produces sex cells through the process called gametogenesis. The process is essentially a step-by-step process of meiosis. Oogenesis (i.e. gametogenesis in females) takes place in the ovaries to produce ova or egg cells. In brevity, the oogonium (the female primordial germ cell) undergoes meiosis to produce four haploid egg cells. Conversely, spermatogenesis (i.e. gametogenesis in males) occurs in the testes to yield sperm cells. Quintessentially, the spermatogonium (the male primordial germ cell) will go through meiosis to give rise to four haploid sperm cells.
Sex cells vs somatic cells
In humans, a sex cell may be identified from a somatic cell in being a haploid cell. That means a sex cell would have half the number of chromosomes as that of a somatic cell. Hence, an egg cell or a sperm cell would have 23 chromosomes whereas a somatic cell would have 46. Haploidy in sex cells is important in order to maintain the chromosomal integrity in humans across generations.
At fertilization, the sperm cell and the egg cell unite to form a diploid cell (called zygote). The zygote, then, divides mitotically, giving rise to pluripotent stem cells. A pluripotent stem cell is a cell capable of giving rise to various precursors that eventually will acquire specific identity and physiological function via a process called differentiation. A differentiated cell means that the cell has matured and acquired a more specific role, for instance as a skin cell, a blood cell, a liver cell, etc.
Somatic cell converted to sex cell
Intrinsically, a human somatic cell that has “differentiated” could never become a sex cell just as a sex cell could neither become nor give rise to a somatic cell. However, this may no longer hold true in the years to come.
Japanese researchers have, for the first time, successfully converted a somatic cell into a sex cell precursor.1 In particular, they had successfully created an oogonium from a human blood cell. They turned blood cells into “induced pluripotent stem cells” (iPS).2 Essentially, the blood cells – turned iPS – appeared to have undergone “molecular amnesia”. It means they forget their initial identity. As a result, they could become any type of cell, even as a sex cell.
The researchers transformed human blood cells into oogonia (plural of oogonium). They did so by incubating them for four months in artificial ovaries derived from embryonic mouse cells. They retrieved promising results. Admittedly though, they acknowledged they are still in the early steps of a rather long journey of research. The oogonia, indeed precursors to egg cells, are, at this point, still young, and thereby, unfit for fertilization. The researchers have yet to induce them to become mature, fully differentiated egg cells. Nevertheless, they remain optimistic in having reached this point, and, undeniably, pioneered an important milestone.
If, in the future, research on the conversion of a somatic cell into a sex cell pushes through to completion, it could lead to significant resolves to infertility issues. However, ethical concerns shall, likely, surface as well. For instance, a possibility could occur in time. A mere hair cell or a skin cell from an unsuspecting person could be turned into an egg or a sperm cell. And from there, an offspring could come into existence.
— written by Maria Victoria Gonzaga
1 Yamashiro, C., Sasaki, K., Yabuta, Y., Kojima, Y., Nakamura, T., Okamoto, I., Yokobayashi, S., Murase, Y., Ishikura, Y., Shirane, K., Sasaki, H., Yamamoto, T., & Saitou, M. (2018 Oct 19).Generation of human oogonia from induced pluripotent stem cells in vitro. Science, 362(6412):356-360. doi: 10.1126/science.aat1674.
2 Solly, M. (2018 Sept. 24). Scientists create immature Human Eggs Out of Blood Cells For the First Time. Retrieved from [link]
Colon Cancer is the third most deadly cancer worldwide. There were more than 1.4 million cases each year and 694,000 deaths globally. The treatment of colon cancer includes chemotherapy, surgery and radiation therapy. However, advances in diagnosis and treatment leads to development and improvement in survival. Numerous data point out that genetic changes function as vital role in the development of colon and rectal cancer. In which regulatory molecules mRNA affects various molecular and cellular target including cancer cells. That is why, development in research used mRNA as based diagnostic biomarkers for colon cancer in human. Furthermore, certain kind of mRNA used to predict survival in colon cancer patients. As well as a better knowledge of molecular mechanisms and associated gene is important for early diagnosis and treatment.
ULBP2 a novel prognostic biomarker in Colon Cancer
ULBP2 is a potential biomarker in colon cancer survival. Previous study shows that matrix metalloproteinase-9 reveals as an important marker for postoperative prognosis in colorectal cancer patients. Also extracellular matrix plays a vital role in cancer progression in which it provides structural and biochemical support in cells. Despite from all of these, digestion is also considered to have a major role related to cancer preventive activity. Additionally, an in vitro of peptides gastrointestinal digestion can inhibit colon cancer cells proliferation and inflammation. Moreover, recent study showed that up and down regulated mRNAs are largely amass in extracellular matrix and digestion. As a result, it would entails that abnormality of extracellular matrix and digestion takes part in colon cancer progression.
Furthermore, the Wnt signaling pathway gives clinical importance on various diseases including colon cancer. Since alteration of this pathway are mostly observed in colorectal cancer with microsatellite instability. So, inhibiting this pathway might be helpful strategy for targeting chemotherapy-resistance cells. Also drug metabolism determined resistance of colorectal cancer resorcinol-based heat shock protein 90 inhibitors. Therefore, Wnt signaling and drug metabolism are both important pathway enriched by up and down regulated mRNAs.
Prognostic biomarkers are very important and have the power to change the course of disease if only knew beyond prognostic factors. In this research ULBP2 gene that encodes cell surface glycoprotein located at chromosome 6 demonstrates prognostic biomarker for colon cancer. High level of ULBP2 is deemed independent indicator for overall survival and identified as the sole outstanding mRNA.
Source: Prepared by Joan Tura from BMC Biological Research
Volume 51:10 March 29, 2018
Pancreatic cancer started at the tissue of the pancreas – an organ in the abdomen that lies behind the lower stomach. Pancreas releases hormones that helps in maintaining the sugar level in the blood and assist in digestion. Pancreatic cancer is hardly detected at early stage and it is recorded as third deadliest cancer in the United States. Some of its symptom includes weight loss, diabetes, jaundice, blood clots, depression and fatigue. However, it is usually characterized at late stage that has been already metastasized. Current therapy of this disease involves adjuvant chemotherapy, surgical resection and radiotherapy. Yet despite of the advancement of the clinical management and therapy the outcome remains unsatisfactory to the patients. So, this novel research of prognostic biomarker helps pancreatic cancer treatment to maximize survival and avoid toxicity.
miRNAs as Prognostic Biomarkers for Pancreatic Cancer
Due to poor prognosis of pancreatic cancer early detection methods have been developed. To have an effective treatment options as well as the importance of critical biomarkers. However, miRNAs shows significance for early detection and diagnosis. It divulges to have great potentials as prognostic biomarkers in pancreatic cancer. miRNAs are small non-coding RNA with 18-22 nucleotides in length that have been known to be associated with tumorigenesis. It is also linked to apoptosis, cell cycle control, proliferation, chemoresistance, metastasis and invasion. This miRNAs modulates key targets and pathways in signaling as well as its unusual expression are associated with chemoresistance.
In terms of chemotherapeutic treatment of pancreatic cancer miRNAs elevated expression inhibits the anti-tumor activity. miRNAs is related to gemcitabine resistance by inhibiting tumor suppressor gene phosphatase and tensin homologue thereby activating the PI3K/AKT pathway. It is also showed that miRNAs expression correlates with prolong overall survival benefits from chemotherapeutic treatment. Additionally, down regulation of miRNAs is responsible for progression of various malignancies including pancreas, breast, prostate, lung and liver cancer. It contains anti-cancer role via modulating targets implicated in cell cycle, apoptosis and DNA repair.
Therefore, it is clear that pancreatic cancer utilizes various mechanisms to maintain a highly resistant phenotype. miRNAs epigenetic controls allow cells to quickly adapt to the genotoxic stress caused by chemotherapy. It is also quickly modulates the mRNA translation in pancreatic cancer cells in response to chemotherapeutic treatment. As a result, various kinds of miRNAs showed great potentials as prognostic biomarkers in pancreatic cancer. Optimistically, these biomarkers will form a solid foundation to have better clinical treatment strategies.To avoid toxicity and enhance the survival rate benefits.
Source: Prepared by Joan Tura from Springer BMC Biomarkers Research
Volume 6:18, 2018
Common bottlenose dolphins are the largest species of the beaked dolphins that inhabits in temperate and tropical oceans worldwide. These species are large that mostly found in groups and known to mixed with other species like whales and cetaceans. Common bottlenose dolphin diet mainly squid, eel, shrimp and wide variety of fishes by swallowing a whole than chewing it. Dolphins usually search prey using echolocation in a form of sonar. And uses sounds for communication like squeaks emitted from blowhole, whistles from nasal sacs and body language. The coastal of United States Pacific is known to have around 450 individuals while the offshore population about 3,495 individuals. In Canadian west coast no common bottlenose dolphin has been documented. However, on July 29, 2017 a sighting of this species mixed with cetaceans and killer whales has been observed.
Common bottlenose dolphins observed in Canadian waters
For the first time common bottlenose dolphins have been observed on July 29, 2017 in Canadian water. Each individual shows particular characteristics like short to moderate beak. A curved mouth line that dips downward resembling like a smile and tall falcate dorsal fin at the central back. Moreover, the body colors were usually light grey to black on the back and side while light to white color around the belly.
The sighting of the large group of common bottlenose dolphins is the first confirmed occurrence in Canadian Pacific waters. The location of sighting is approximately 1000 km northwest coast of America which signifies the first northernmost record of the species. About 200 dolphins were seen in the group in an unusual large aggregation. On the other hand it was also observed that this dolphins traveling closely with false killer whales, a typically offshore species.
The discovery of common bottlenose dolphins and false killer whales signifies the warming trends in North Pacific waters. Both of the species typically inhabit warm temperate waters in lower latitudes. But this sighting indicates that British Columbia, Canada oceanic conditions gives suitable habitat for them. It is also recorded that the show-up happened after a prolonged warming period.
Source: Prepared by Joan Tura from Springer Nature BMC Marine Biodiversity
Vol. 11: 3, 20 April 2018
Gravity is a natural phenomenon that affects all things particularly all living creatures from cell to human being. It has an infinite range, although its effects become weaker on farther objects. This article is not based on observation on either human or animal. But it is based on extensive and attentive results of scientific studies on sleep performed in ground, water and space. Since the effect of gravity on sleep has been rarely studied and medical aspects give much of attention. Man live in the presence of gravity for million years but with the advent of space flight. Man can able to live in the absence of gravity.
Why do we sleep?
The hypothesis presented here is that sleep is partly due to gravity. It try to explained several theories why sleep is a part of life in which it is one parameter. That all creatures on Earth undergo an alternative wake and sleep periods. Like in water, species modes of sleep are different from those of mammals. In which the rapid eye movement phase of sleep is not apparent, like in fishes. For insect, it is believed that there are alternating active and passive periods. Even planktons and unicellular organisms correspond to the necessity of using energy. In which it tends to move lower at night and goes up to the surface during daytime.
On the ground, gravity influence REM (Rapid Eye Movement) sleep wherein muscle tone helps maintain posture. When asleep the brain decreases its sensitivity to the external stimulus like sound, light, contact and weight. Like for example, horses can sleep while standing locking their knees to stay upright. But they cannot achieve REM sleep if they will not lay on the ground, the same also in the elephants. Indeed, gravity is forgotten by the brain during REM sleep.
In space, many studies explained that sleep differs minimally from Earth in which sleep duration in space is shorter. Sleep is one concern in space but the absence of gravity affects muscles and bones. Absence of it produces atrophy of muscles and loss of strength in bones in which these two are important in sleep. In water also demonstrate that biological sleep is dependent on gravity because without it sleep is reduced.
Therefore, evidences shows that sleep depends on the gravity that acts on the body either in water, space and ground. When gravity is compensated, sleep is affected. Because there is no tool to suppress gravity, it is hard to ascertain a long term experiment over generations to confirm that sleep is due to gravity.
Source: Prepared by Joan Tura from Medical Hypotheses
Volume 113, April 2018, Pages 81–84
Here is an interesting article from “sent2null” written by David Saintloth, regarding Einstein’s uncanny output in 1905. Not exactly biological in origin, but Einstein as a scientist is an inspiration to all.
1905 was a great year for physics, in this year a 24 year old patent examiner in Bern Switzerland published 4 fundamental papers in physics in 4 disparate areas of the field. The topics included special relativity, the relationship between energy and matter, Brownian Motion and the subject of this post, the photo electric effect.
The photo electric effect paper by Einstein was probably the most practical paper next to the brownian motion paper in that it provided an answer to a long standing problem in electromagnetic theory at the time that had stood as an embarrassment to particle physics. This embarrasment was a legacy of the work of James Clerk Maxwell and his fundamental equations of electromagnetism, by using a continuous wave analog to describe the energy of propagating fields Maxwell was able to do the astonishing, he explained the riddle that was the relationship between electricity and magnetism in clear mathematical terms and he was able to show how light must be itself an electromagnetic wave by showing that all such waves are limited by the speed of light “c” or roughly 186,000 miles per second.
For the rest of the article: http://sent2null.blogspot.co.il/2009/11/1905-annus-mirabilus-photo-electric.html