This week I read an article about Marsupials and the curiousness of their limb development. I found this reading on ScienceDaily's website and is entitled Marsupial Embryo Jumps Ahead in Development . The researchers at Duke University claim that the "developmental program executed by the marsupial embryo runs in a different order than the program executed by virtually every other vertebrate animal". This, although interesting, is already widely known. The interesting part of the article is when they talk about how they are developmentally different. The researchers studied the limbs of the embryonic short-tailed opossum. They found that not only is limb development occurring at a different order of typical vertebrate development, but also that the development of the limbs is occurring before almost any other structure. Previously limb development has been thought to be triggered by the development of other structures in the body but at least in the case of the short-tailed opossum limb development is occurring without these triggers. It is suspected that these results will hold true for many if not all other marsupials as well. This doesn't even correlate to all of the limbs; the forelimbs are what mainly develop early because they are used to drag themselves across their mother in search of her teat in order to feed. While the forelimbs contain developed muscle and bone, the hind-limbs still are rubber like and weak. It is amazing that such an underdeveloped animal can actually survive living outside the mothers womb at such an early age. Though the baby may have a harder time surviving, marsupial mothers in general have an easier time surviving because if resources become scarce or they need to evade a predator, they can easily give up their baby to save them selves and reproduce later. Overall I think that this article was very interesting because the results suggest that development is much more flexible than we have previously thought.
November 2010 Archives
This article entitled Sea Creatures' Sex Protein Provides New Insight Into Diabetes suggests that genes in sea urchins can explain why a rare form of diabetes called Diabetes Insipidus occurs. Diabetes Insipidus causes a person to urinate more than three liters a day. People with this disease lack the ability to produce vasopressin which tells the body how much urine to make. Professor Maurice Elphick, from Queen Mary's School of Biological and Chemical Sciences, says that sea urchins produce NG peptides (responsible for releasing their sperm and eggs at the same time) very similarly to how humans produce this vasopressin. He believes that we can trace our genetic history back to a common ancestor between sea urchins and humans where a one-off genetic accident when a gene that was responsible for making vasopressin-like molecules mutated and became a gene for NG peptides. Research on how sea urchins produce NG peptides can reveal how humans produce vasopressin. This could lead to ways in which Diabetes Insipidus could be cured or prevented.
I stumbled upon an interesting video/article on Science dailys website entitled Doggy Genes Newly Sequenced Genome Could Shed Light on Human Diseases. Researchers have completed the first complete genetic map of a Boxer's (dog breed) genome. Researchers are hoping that not only will this lead to a better ability to treat diseases in dogs, but also help treat and find cures for diseases in humans. Dogs and humans share many diseases such as diabetes, epilepsy, and cancer If they can identify the genes that cause these diseases in dogs they may be able to find a cure. If they can find a cure that works on dogs then it would be likely that it could cure the diseases in humans due to the similarities between our genomes. Dogs make an excellent genome to search for genes for common diseases with humans because a disease that is caused by a dozen genes in a human is only caused by one gene in dogs. This makes things a lot easier to identify and study. Implications of this research are that there are many different breeds of dogs many of which have higher predispositions for certain diseases. Currently they have only mapped out the genes of one breed of dogs, boxers, it would be helpful for them to map out the other breeds of dogs and look for specific genes in specific breeds.
This week I read a very interesting article on the science daily website entitled Modeling Autism in a Lab Dish: Researchers Create Autistic Neuron Model . Autism has previously been viewed as a learned disorder thats caused by bad parenting skills however it has been found that in almost all cases of autism it is caused by a mutation in the MeCP2 gene. The researchers used iPS skin cells from autistic participants. The skin cells were then "encouraged" to have the same mutations and damages as autism. They then created fully functional neurons from the cells at which point the researchers compared the cells of autistic participants to those in the control group. They found that the autistic cells had smaller cell bodies, a reduced number of synapses and dendritic spines, specialized structures that enable cell-cell communication, and electrophysical defects. However, when they added insulin-like growth factor 1 (IGF-1) to the cells, the differences decreased. Their research suggests that in the future it is possible to cure autism to some extent. This research could also be used to treat and cure other psychiatric disorders as well. If implemented, this research could improve the lives of millions of people with psychiatric disorders.
To read more, the original article was published in the November 12, 2010 issue of Cell.
This week I read a very interesting article entitled Gene mapping project offers new clues about humanswritten by Julie Steenhuysen. In this article the researchers are trying create a map of genetic varients in humans. They believe that this information will allow us to better understand the genetic basis' of human diseases for both common and rare diseases. Dr. Evan Eichler of the University of Washington is in the process of mapping out 2,500 people's genomes from around the world. Although it is difficult to compare these genomes, it will hopefully give us an idea of why certain people have certain diseases. I think this research is very important because if we can identify the genes that lead to certain diseases then it would be possible to treat the person earlier giving them a higher rate of recovery. I think it would be interesting to follow up on this research and see where it leads us in the future.