Daphne Zbaeren-Colbourn

Bern, Switzerland

Subject Matter:

Acrostichum aureum, mangrove fern (TS leaf midrib)


Brightfield, Fluorescence


When a cell divides, it produces a mitotic spindle which then makes sure that the chromosomes are divided equally between the two new cells. Failure to do so efficiently can lead to problems; those cells with either too few or too many chromosomes are at risk of becoming cancerous.

Clathrin is a protein that is involved in the process of membrane trafficking in interphase cells, but it switches role during mitosis and localises to the mitotic spindle where it works alongside TACC3 and ch-TOG to form these bridges.

Professor Royle explained, “That sounds like a negative, the idea of a cell dying. However it’s vital to remember that most adult cells are no longer dividing and what we are suggesting is being able to shut down mitosis in those that are multiplying.”


The insertion of one gene can muzzle the extra copy of chromosome 21 that causes Down’s syndrome, according to a study published today in Nature. The method could help researchers to identify the cellular pathways behind the disorder’s symptoms, and to design targeted treatments.



"Scientists have known that Bmi1 is a central control switch within the adult stem cells of many tissues, including the brain, blood, lung and mammary gland,” said Ophir Klein, MD, PhD, who directs the Craniofacial and Mesenchymal Biology (CMB) Program and serves as chair of the Division of Craniofacial Anomalies at UCSF. “Bmi1 also is a cancer-causing gene that becomes reactivated in cancer cells.”

Researchers focused on stem cells (yellow) at the base of the growing mouse incisor, which dwell within a surface layer of cells (dark green). The stem cells spin off precursor cells (light green), which in turn give rise to ameloblasts (blue), which are the cells that make enamel (red). Odontoblasts (orange) arise from a different group of stem cells and make dentin (white). (Credit: Jimmy Hu)

In the current study, postdoctoral fellows Brian Biehs, PhD, and Jimmy Hu, PhD, determined that there is a group of adult stem cells at the base of the growing mouse incisor and that these stem cells possess active BMI1. They showed that BMI1 can suppress a set of genes called Hox genes that, when activated, trigger the development of specific cell types and body structures. In the mouse incisor, the researchers showed that activity of BMI1 in the stem cells maintains their stem cell fate and prevents inappropriate cell differentiation by suppressing the expression of Hox genes.


Dr. David McDonald

Chicago, Illinois, USA

Subject Matter:

Fibroblast cells



A fibroblast is a type of cell that synthesizes the extracellular matrix andcollagen, the structural framework (stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals.

(via sciencenote)

Microneedle vaccine
This scanning electron micrograph (SEM) shows an array of ‘microneedles’ made from a biodegradable polymer. Researchers have shown these materials can be used to deliver vaccines and therapeutics to the outer layers of the skin in a safe and painless way. Because the microneedles avoid contact with blood vessels and nerve endings in the deeper skin layers, microneedle application prevents pain and the transmission of blood-borne pathogens. In addition, because the skin is so accessible, microneedle application can be performed quickly, requires minimal training for healthcare providers and makes self-application by patients possible. Each microneedle is approximately 700 microns high and 250 microns wide at the base.

Credit: Peter DeMuth / Wellcome Images
Chicken embryo vascular system
This fluorescence micrograph shows the vascular system of a developing chicken embryo (Gallus gallus), two days after fertilisation. Injecting fluorescent dextran revealed the entire vasculature used by the embryo to feed itself from the rich underlying yolk inside the egg. The image shows the central chicken embryo surrounded by veins and arteries. The head of the embryo, including the embryonic eye and brain, can be seen on the upper part of the embryo, just above the embryonic heart. The long lower part of the embryo is the future body of the chicken, from which legs and wings will develop. At this stage of development, the embryo and its surrounding vasculature are a little smaller than a 5p coin.

Credit: Vincent Pasque, University of Cambridge


Curiosity as is seen by Einstein (above, via Physicist Tv) and by XKCD (below, via XKCD).

Repair of ventricular sepal defect
This photograph shows the surgical repair of a traumatic ventricular septal defect (VSD). A VSD is a hole between the right and left ventricles of the heart and is usually seen as a congenital condition, known as a ‘hole in the heart’. A traumatic VSD, as seen in this case, is a rare complication of chest injury. It might manifest immediately after trauma, leading to heart failure and an inability to stabilise a patient, or it might be delayed and detected months later. Traumatic VSDs can be treated in a variety of ways, depending on the effect they have on the patient. Treatment options range from monitoring and a conservative approach to open surgery, as is depicted here. In this image, the VSD is seen at the bottom, and a bovine patch is being parachuted and stitched into place to seal the defect.

Credit: Henry De’Ath, Royal London Hospital / Wellcome Images