Graphical Abstract POPs in Antarctic Mammals.

A vacuole is a membrane-bound subcellular structure involved in intracellular digestion. Instead of the large "vacuolar" organelles that are found in plants and fungi, animal cells possess lysosomes that are smaller in size and are enriched with hydrolytic enzymes similar to those found in the vacuoles. Large vacuolar structures are often observed in highly differentiated mammalian tissues such...

DNA methylation is one of the best characterized epigenetic modifications. In mammals it is involved in various biological processes including the silencing of transposable elements, regulation of gene expression, genomic imprinting, and X-chromosome inactivation. This article describes how DNA methylation serves as a cellular memory system and how it is dynamically regulated through the action...

Biologists often think of mitochondria as static, kidney bean-shaped organelles that have the mundane chore of providing energy for the cell. However, the mitochondrial population is in fact dynamic (Bereiter-Hahn and Voth, 1994; Rizzuto et al., 1998), and the hundreds of mitochondria in a cell can have a range of morphologies, including small spheres, long tubules, and interconnected tubules. ...

1. Oxygen in concentrations of over 70 per cent of an atmosphere is poisonous to dogs, rabbits, guinea pigs and mice. 2. The poisonous effects manifest themselves in drowsiness, anorexia, loss of weight, increasing dyspnea, cyanosis and death from oxygen want. 3. The cause of oxygen want is a destructive lesion of the lungs. 4. The lesion may be characterized grossly as an hemorrhagic edema. Mi...

One year ago, JJ1 was Europe's most famous mammal. The male brown bear, also known by the more amiable name of 'Bruno', had wandered into Southern Germany from the Trentino in Italy. The appearance of this charismatic animal in a region where the last bear had been seen and killed 170 years ago seemed to fit a trend. Over the past ten years, wolves, elks, beavers and lynxes have been highly pub...

Ingestion is a series of biologically complex activities (capture, incision, transport, mastication, swallowing and, in infant mammals, suckling) performed by the oral apparatus. The oral apparatus includes the dentition, the masticatory muscles, numerous bones of the cranium, the squamosal–dentary joints connecting the lower jaw to the skull, the tongue, and many other structures in the head. ...

Epigenetic information can be passed on from one generation to another via DNA methylation, histone modifications, and changes in small RNAs, a process called epigenetic memory. During a mammal's lifecycle epigenetic reprogramming, or the resetting of most epigenetic marks, occurs twice. The first instance of reprogramming occurs in primordial germ cells and the second occurs following fertiliz...