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Sox9 Evolution PP

Submitted by maurabenson on Tue, 04/25/2017 - 23:56

 There is substantial evidence that Sox9 functions in the development of the male gonads in many species. Sox9 is mostly expressed in male gonads in the developmental stage of mouse fetuses, regulating the Mis gene which codes for production of the anti-mullerian hormone that stops the mullerian ducts from forming into the uterus and the fallopian tubes. Even in transgenic mice with two X chromosomes that were then engineered to induce the overexpression of Sox9, the mice still developed testes. However, in non-mammalian vertebrates, the Sox9 has a slightly different function. For example, in mice the Sox9 gene is expressed prior to the Mis gene, but in other species such as chicken, it is actually the opposite. This sugests that Sox9 is not essential to express Mis in chicken. Zebrafish also have two versions of the Sox9 gene where one version is expressed in the oocytes of the ovaries and the other is expressed in the sertoli cells in the testes. This does not happen in all other vertebrates.   Another difference is in the medaka, which are Japanese rice fish as well as vertebrates and they express the Sox9 in the oocytes but not in the gonads. They also have no Sox9 expression in their somatic cells but expression in their germ cells.

Sox9 Evolution

Submitted by maurabenson on Tue, 04/25/2017 - 23:49

The SOX9 gene is essential to the development of sex and skeletal development. It codes for a transcription that plays a part in multiple different pathways that contribute to formation of testes and cartilage. SRY (sex determining region on chromosome Y) works with Sox9 to begin development of the testes from the bipotential gonads, meaning they can either form ovaries or testes. It is also expressed with Coll2a1 which is a type 2 of collagen. Sox9 also contains the SRY-related HMG (high mobility group) box. Many species have a variation of this gene in their genomes, including mammals and birds. More specifically, the role of Sox9 in gonad differentiation is highly conserved in chicken, sea turtle and alligator, but can function differently in other vertebrates.

      There is substantial evidence that Sox9 functions to develop the male gonads. Sox9 is mostly expressed in male gonads in the developmental stage of mouse fetuses, regulating the Mis gene which codes for production of the anti-mullerian hormone that stops the mullerian ducts from forming into the uterus and the fallopian tubes. Even in transgenic mice with two X sex chromosomes was engineered to induce the overexpression of Sox9, the mice still developed testes. However, in non-mammalian vertebrates, the Sox9 has a slightly different function. For example, in mice the Sox9 gene is expressed prior to the Mis gene, but in other species such as chicken, it is actually the opposite. Zebrafish also have two versions of the Sox9 gene where one version is expressed in the oocytes of the ovaries and the other is expressed in the sertoli cells in the testes. This does not happen in all other vertebrates.   Another difference is in the medaka, which are Japanese rice fish as well as vertebrates and they express the Sox9 in the oocytes but not in the gonads. They also have no Sox9 expression in their somatic cells but expression in their germ cells.

      From this study and many others, there is sufficient evidence to conclude that while Sox9 plays a role in sexual determination in vertebrates, the mechanism for which this occurs can vary from species to species. This also would make sense due to the different types of sex determination, such as the XY system or ZZ/ZW for other species like chicken. Due to Sox9’s importance in skeletal formation, it also would make sense for the sequence  to be highly conserved in vertebrates in order to maintain proper bone (including spinal cord) formation. 

Poster Background

Submitted by maurabenson on Tue, 04/25/2017 - 23:47

 

Mosses are a multipurpose plant that provide services both ecologically and economically. Economically, mosses serve as fuel in some countries, as well as a landscaping tool. Ecologically, mosses help with insect shelter, absorbance of oil spills, and flood control(Rochefort). Unlike other plant species, mosses do not contain a vascular system, meaning they do not have vessels for conducting water. They are capable of uptaking water, through capillary action and absorbing it directly into their bodies (van Breemen). Mosses that live in a moist environment are  more susceptible to water absorption, therefore Sphagnum is expected to have the highest water capacity.

Sphagnum is a genus of moss that is adapted to wet and bog-like environments, and grows in large patches on a water’s surface (van Breemen). D. H. Boelter comments on the overall absorption of Sphagnum saying that the surface of the moss can absorb 95-100% water by volume at saturation. The leaf-like structures on the Sphagnum allow for high water absorbance in a small amount of time, making this experiment a valid way to test its absorbance capacity.    

    While Sphagnum has various environmental uses, Rochefort discusses the various functions Sphagnum can have in commercial materials. Through the last few decades it has been increasingly used as a buffer to fight flooding, a source of seeds after forest fires, a way to preserve artifacts, and a source for atmospheric regulation. These materials have positively affected aquatic areas especially during rainy seasons. With Sphagnum possessing the quality to be such a good absorbent, it poses the idea on whether it can be a better adsorbent material than other synthetic materials, such as sponges. Sponges could be potentially used as a synthetic material by humans to help in flood prevention in vulnerable environments.

This experiment was based off of the research of T.J.K Dilks who performed an experiment regarding the photosynthesis, respiration and water contents of bryophyte moss. In this experiment, the author took moss from outside a greenhouse to test the effects of water content on photosynthesis and respiration. In order to quantify how much water the bryophytes contained, they were all saturated and then dried to different water contents using an oven. Theses were verified with osmotic stress calculations using a Warburg apparatus. With this procedure in mind, methods were designed using the same principle, but an opposite approach.

D.W. Larson also had methods that are replicated in this experiment. This research analyzed the role of morphology in the wetting of lichens and mosses. Samples used were originally dried or contained 3-5% water weight, and time intervals were used to measure the absorbance of the lichen or moss. Some techniques were replicated for this experiment with both Sphagnum and other materials. Since Sphagnum is physiologically capable of absorbing high quantities of water, the research will be conducted in order to determine if it is the best material to control potential floods.

Poster Abstract

Submitted by maurabenson on Tue, 04/25/2017 - 23:46

This research tests samples of Sphagnum to determine which is the most favorable water absorbent in a controlled environment. Sphagnum is a multi purpose moss genus that is known for its high absorbance capacity. In recent years, Sphagnum has been developed to be used commercially as an absorbent board, which is turned into sanitary towels, and absorbents for oil spills and floods. Live and dead sphagnum were analyzed for their absorbance capacity. Materials were left in a controlled environment for a period of time and the absorbance was measured. The data was analyzed to conclude if live or dead Sphagnum was the most successful material for flood control.  

 

Brainstem PP

Submitted by maurabenson on Sun, 04/23/2017 - 18:42

The brain stem is an essential part of our central nervous sysem connecting the  cerebrum, cerebellum, and spinal cord. There are three different parts of the brainstem: the medulla, pons and the mid brain. The medulla regulates unconscious actions such as breathing, heartbeat, and blood pressure. The midbrain deals with the auditory and visual processing and sends the information to the prospective cortexes. The pons is important in regualting the sleep wake cycle and arousal. Like the spinal cord, white matter is on the outside of the brainstem and gray matter is on the inside. The brainstem also contains long tracts which as long axons that all go together to the same place, including upper motor neurons and somatosensory tracts. Without the brainstem receiving important information and sending it to the correct portion of the brain, neccesary functions for life would nto be possible. 

The Brain Stem

Submitted by maurabenson on Sun, 04/23/2017 - 18:35

The brain stem is an essential part of our central nervous sysem connecting the  cerebrum, ccerebellum, and spinal cord as well as all the cranial nerves. There are three different parts of the brainstem: the medulla, pons and the mid brain. The medulla regulates unconscious actions such as breathing, heartbeat, and blood pressure. The midbrain deals with the auditory and visual processing and sends the information to the prospective cortexes. Like the spinal cord, white matter is on the outside of the brainstem and gray matter is on the inside. The brainstem also contains long tracts which as long axons that all go together to the same place, including upper motor neurons and somatosensory tracts. 

Research Assistant Essay Excerpt

Submitted by maurabenson on Thu, 04/20/2017 - 22:57

Through planning, conducting and analyzing these experiments on my own, I will gain experience that will help me succeed in regards to my thesis as well as cultivating skills that will be advantageous in the research field after graduation. Academically, I will be able to see what I have learned in my classes happening in my research such as the embryology and development of zebrafish, which has been discussed in my genetics class. Also, having this research experience gives me a larger feel for the research field and whether or not it is something I want to pursue. Personally, performing this experiment on my own will help teach responsibility, time management and allow me to make a greater contribution to the scientific community with my findings. I hope to continue to build upon the skills I have in the lab and run this project in hopes of discovering something new. 

BMP Pathway

Submitted by maurabenson on Thu, 04/20/2017 - 22:54

The BMP pathway (bone morphogenetic protein) is the pathway which a signal transduces to regulate the bone morphogenetic protein. BMP is a transforming growth factor of the beta class which plays a crucial role in bone formation and organ systems, as well as a role in embryogenesis and development. One disease that involves mutation of the BMP signaling pathway is Myhre Syndrome, which is classified by mental retardation and dysmorphic facial features. This could include microcephaly, midface hypoplasia where the upper jaw and cheekbones and eye sockets are not grown to fit the face. There are also many skeletal abnormalities associated with it such as short stature, broad ribs, iliac hypoplasia and flattened vertebrae. Mutations in the gene SMAD4 which plays an important role with TGFB (transformational growth factor beta-1) and BMP can cause this phenotype due to a defect in ubiquitination of SMDA4, causing an altered expression of TGFB and BMP.

            Using the malformations that occur in these diseases due to the mutations in these genes are essential to finding the function of the genes. Many geneticist use the idea of “learning by breaking” where they cause a mutation in certain genes to see what the phenotype is when there is defect in the gene. If the organism dies, then that gene is essential for life. It can also show where that protein is expressed when there is a defect in that area. For example, with the SOX9 gene diseases, many of the symptoms were malformations in skeletal systems, showing that the SOX9 is essential in proper bone formation. 

CPMD PP

Submitted by maurabenson on Thu, 04/20/2017 - 22:47

 Besides Pierre Robin Syndrome, there are many other diseases that emerge when there are defects in the SOX9 gene. Campomelic Dysplasia is caused by a heterozygous mutation in the SOX9 gene and by other genetic mutations as well. This is an autosomal dominant mutation causing skeletal dysplasia, which is abnormal bone development which can cause dwarfism among other skeletal defects. It also can cause congenital shortness and bowing of long tubular bones. The phenotype could also include a hypoplastic scalpula, meaning that their scapulae (shoulder blades) are elevated and malformed. They also may have narrow iliac wings and non-mineralized thoracic pedicles. This can be caused by the instability of the SOX9 transcription factor, which causes problems with skeletal development. It can also play a role in gonadal dysgenesis when there is a poor interaction with SRY, the sex determining region on chromosome Y. This disease is usually lethal within the first year of life.

Journal- SOX9 Diseases

Submitted by maurabenson on Thu, 04/20/2017 - 22:45

The SOX9 gene is crucial to the development of sex and skeletal development. It codes for a transcription that plays a part in multiple different pathways that contribute to formation of testes and cartilage. The SRY (sex determining region on chromosome Y) works with this transcription factor to begin development of the testes from the bipotential gonads, meaning they can either form ovaries or testes. It is also expressed with Coll2a1 which is a type 2 of collagen. Mutations in the SOX9 gene cause skeletal defects due to the body being unable to efficiently produce collagen. It was also found that the SOX9 gene is expressed in chondrocytes, which are cells that secrete cartilage.

            Besides Pierre Robin Syndrome, there are many other diseases that emerge when there are defects in the SOX9 gene. Campomelic Dysplasia is caused by a heterozygous mutation in the SOX9 gene, among other genetic defects. This is an autosomal dominant mutation causing skeletal dysplasia, which is abnormal bone development which can cause dwarfism among other skeletal defects. It also can cause congenital shortness and bowing of long tubular bones. The patient could also have a hypoplastic scalpula, meaning that their scapulae (shoulder blades) are elevated and malformed. They also may have narrow iliac wings and non-mineralized thoracic pedicles. This is caused by the instability of the SOX9 transcription factor, which causes problems with skeletal development. It can also play a role in gonadal dysgenesis when there is a poor interaction with SRY. This disease is usually lethal within the first year of life.

            Melanoma is a dangerous type of skin cancer that often occurs to excessive sun damage. This cancer causes abnormal growth of the melanocytes, which are the pigment producing cells. It usually happens in skin, but can also occur or metastasize to other parts of the body. While SOX9 may not be the main factor causing this disease, the melanocytes that are cancerous have generally weak or absent SOX9 protein. When SOX9 was overly expressed in cancer cell lines, the growth of tumors was inhibited, showing that SOX9 plays a role in growth signals as well. Without SOX9, there is a desensitization to retinoic acid, which is synthesized by Vitamin A and used to regulate epithelial tissue growth, development, and programmed cell death. 

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