Trypanosoma cruzi CDC

Researchers have discovered that the parasite Trypanosoma cruzi survives inside its human host by preventing infected cells from triggering cell death. Trypanosoma cruzi causes a potentially life-threatening disease in humans known as Chagas' disease. It causes a life-long infection that is typically transmitted to humans by blood-sucking triatomine bugs.

According to researchers, these parasites release a protein called PDNF that inhibits the release of molecules that signal cell destruction in infected cells. This gives the parasite time to grow, develop and spread to other cells. It was also discovered that not only does PDNF inhibit cell death, but it also promotes the production of an enzyme that increases nutrient absorption. This further adds to the chances of survival for the parasite.

Learn more about this discovery:

• Parasite Evades Death by Promoting Host Cell Survival Science Daily

© Steve Berg

Can you identify the type of genetic cross that is shown in the image? This type of cross is used to identify the inheritance pattern of a single trait controlled by different alleles. This cross can be done between two individuals that are either homozygous or heterozygous for a single trait.

A. dihybrid
B. monohybrid
C. incomplete dominance
D. phenotype

Test your knowledge of Mendelian genetics. Take the Genetics Quiz! Need to brush up on genetics before taking the quiz? Visit:

• Mendel's Law of Segregation
  
• Independent Assortment

Salmonella typhimurium David Goulding, Wellcome Trust Sanger Institute

Antibiotic resistant bacteria have become a worldwide public health issue. Researchers have identified a new strain of Salmonella typhimurium, called ST313, that has become more virulent among people living in sub-Saharan Africa regions.

The bacteria have undergone genetic changes that have allowed them to not only become resistant to commonly used antibiotics, but they are also less responsive to drugs in which they have not gained resistance. Researcher Dr. Chisomo Msefula states, "Our findings show that ST313 has acquired a block of genes that make it resistant to the common antibiotics. The genes jumped into ST313 on a mobile genetic element called a transposon, bringing with it additional genes that make the strain more deadly." The researchers hope that insight gained from this study can be used to develop new vaccines to fight against these and similar pathogens.

Learn more about this discovery:

• Biology of Emergent Salmonella Exposed Science Daily

Endothelial Cell Microtubules (green) Public Domain/NIH

Microtubules are fibrous, hollow rods, that function primarily to help support and shape the cell. They also function as routes along which organelles move. They are typically found in all eukaryotic cells and are a component of the cytoskeleton, spindle fibers as well as cilia and flagella.

Microtubules play an important role in the movement of chromosomes during cell division. They form the spindle fibers that manipulate and separate chromosomes during mitosis and meiosis. Examples of microtubules that assist in cell division are centrioles, polar fibers and kinetochore fibers.

More Cell Structures:

• Cell Structure
  
• Cell Anatomy Quiz
  
• Animal Cells