Female sex determining gene identified in mice

 

Researchers from the Francis Crick Institute and the University Côte d'Azur, in collaboration with labs in France and Switzerland, made a breakthrough by identifying the key role of the Wt1 gene in early ovary development in mice. In mice, the presence of XY or XX chromosomes leads to testes or ovaries development. This outcome is determined by the activity of specific genes including the Sry gene on the Y chromosome (responsible for testes development). The research revealed that the -KTS form of the Wt1 protein is important for the formation of both Sertoli and granulosa cells in gonad development. When the researchers genetically manipulated mice to produce only the -KTS form of the protein, an excess of -KTS inhibited the expression of Sry in XY gonads (which prevents testes development). XY mice with an abundance of -KTS developed female gonads which demonstrated that -KTS is a key early trigger for female gonad development regardless of the chromosome configuration (XX or XY).

In humans mutations in WT1 can lead to Frasier syndrome, which affects kidney function and gonad development. Individuals with XY chromosomes and Frasier syndrome develop ovaries, which degenerate before birth. This discovery not only provides insight into the crucial early stages of gonad development and its impact on an individual's sex determination but also has broader implications for understanding WT1's role in kidney development. Wilms tumor, which is a type of kidney cancer, is also an uncovering mechanism underlying cell fate determination.

Links -

Female sex determining gene identified in mice | ScienceDaily

Researchers identify female sex determining gene in mice (phys.org)

Autism Spectrum Disorder and the Genetic Contributions

     Autism is usually discovered in early childhood by communication dysfunctions and social interactions as well as repetitive and restrictive behaviors and interests.  Autism spectrum disorder is a heterogeneous group of neurodevelopmental conditions set by specific criteria. The main areas affected by this disorder are language level, intellectual functioning, and co-occurring psychiatric and medical difficulties, all of these ranging from very severe to moderate.  The male-to-female ratio of autism is 4:1 in a clinical study.  This sex difference is unknown why but there are a few ideas that were thrown around, one being that there are more underdiagnoses and misdiagnoses in women.  70% of people with autism have other conditions alongside it, the main ones being ADHD, anxiety, depression, epilepsy, sleep problems, and gastrointestinal and immune conditions.  The twin studies suggest that 9-36% of the variance in autism could be from environmental factors, not genetic ones.  From pregnancy-related nutrition factors to heavy-metal exposure, there is a wide range of factors that could be associated with autism outside of the genetic conclusion.  Looking into the genetic world of autism, there are findings from linkage, candidate gene studies, common and rare genetic variation studies, epigenomics, and transcriptomics.  Linkage studies can show the regions of a chromosome that are inherited in affected individuals.  Another example is the SNP-heritability of autism which ranges from 65-12%, showing that variation of a single nucleotide could play a big part in this inheritance.  Looking through this paper there is so much information on different studies down to help prove these theories. There are so many different factors that can contribute to autism and many methods discovered to help investigate the genetic variants that carry out autism and autistic traits.

    The first image, a, explains variance by different classes of variants in autism.  The shades of green show familial recurrence and the purple being the environmental factors that could contribute.  Image b is showing showing the variance change in phenotypic subgroups.  

https://www.sciencedirect.com/science/article/pii/S2001037020303007#:~:text=In%20GWAS%20studies%2C%20SNP%20heritability,measured%20genetic%20variants%20influence%20phenotypes. 

https://www.cambridge.org/core/journals/psychological-medicine/article/genetic-contributions-to-autism-spectrum-disorder/89240047F6928249D9DE91A6A6CFBD52

Red Hair, Vampires, Red-Headed Irish Leprechaun and Many More

It was historically known that in certain countries and cultures, people who had red-hair were considered to have a bad genetic trait. It was strongly associated with strong-willed, mischievous bullies. ''Gingerphobia'' was a termed that was coined to describe the fear of red-heads and ''gingerism'' is the bullying of or prejudice against redheads. In Egypt, it was known that people who had red hair were burned. People with this color hair have some interesting medical facts; they tend to be left-handed and less sensitive to absorption of Vitamin D. Red-hair is a recessive trait and is often associated with low concentration or the absence of melanin. It a secondary mutation of the melanocortin 1 receptor (MC1R) gene, found on the 16 chromosome. This mutation can be found around the world but it is most common in Scotland. 

This is connected to genetics since this is a genetic mutation. Having red hair is a rare and it was also historically badly seen as a bad trait just like previous or present day rare traits. 

http://health.usnews.com/health-care/for-better/articles/2017-03-17/genetics-the-common-thread-of-redheads-st-patrick-vampires-and-culture

How Much of A Chromosome is DNA?

It has come to light recently that DNA makes up only half of the material inside chromosomes. This is less than what was thought prior to this study. Almost half of the structure is a sheath which surrounds the genetic material in the chromosome. During this study, at the University of Edinburgh, 3D models were produced for the first time ever, of each of the 46 human chromosomes. A microscopy technique was developed in order to study the structure called 3D-CLEM. This method uses a combination of electron microscopy and light along with computational modeling software which gives high-resolution 3D images of chromosomes.

When looking at these images, there is material containing DNA and supporting proteins which is said to account for 53 and 70 percent of the total content of the chromosome where as the remaining percentage is composed of chromosome periphery. Prior to this study, it was assumed that chromosomes were composed primarily of chromatin.This new research brings questions into how chromosomes are built and segregation during cell division since there is thick layer of this material covering the genetic material. This groundbreaking study into the models of chromosomes is amazing and can lead way to so much more information regarding the human chromosomes.

Researchers find link of decreased bone density in two chromosomes

   

British researchers identified two common mutations that increase the risk of osteoporosis and related bone fractures.

Osteoporosis is a condition where bone density things as bone cells are lost then replaced as people age. It occurs more in women than men.





In a Lancet study, the researchers scanned the genes of 2,084 female twins and found that there was a link which caused decreased bone density in chromosomes 8 and 11. Chromosome 11 was responsible for a 30% increase in the risk of the condition while chromosome 8 was responsible for 20%. Researchers are going to use this information with the two genes involved as the targets to come up with drugs and other treatments,

This article was written in 2008 and I am not sure of what progress in terms of treatment has been made on this disease. However, it is good to know that the chromosomes and genes responsible for certain diseases are getting discovered and that more and more research is being done. Once you find the genes or chromosomes responsible, it allows scientist and researchers to formulate a drug that can treat the disease.

Neuroticism Genetics Uncovered

Commonly studied mental disorders all have to deal with some sort of chemical unbalance in the brain, whether it is too much of one neurotransmitter or not enough of another. These abnormalities contribute to the way people with mental disorders and other mental issues act. One of the results of these abnormalities is a trait called, neuroticism, which makes people respond to something bad, like a threat or a death, with negative emotions. It is normal to want to feel sad when something bad happens, but those with neuroticism suffer more severe and more frequent bouts of anxiety, depression, guilt, anger and envy then those without the trait when faced with a negative event.

For as long as genetics have been studied, scientists could only find one possible locus on chromosome 3 where neuroticism could form, but new studies conducted by the University of Glasgow's Institute of Health and Wellbeing show that there there are at lest 9 different loci that have to deal with neuroticism. As Professor Daniel Smith, one of the scientists at the institute, says "this is an exciting discovery because we have identified, for the first time, genetic risk factors for a personality trait which is of fundamental importance to physiological well-being."

Even though these genes have been found, there is still the question of how they make people behave the way they do when they have neuroticism. One that was found was a gene called CHRH1 that contributes to the body's stress management and also makes laboratory mice anxious, just like it would if it were in the human body. A couple of other genes deal with the neurotransmitter glutamate, a factor in depression and schizophrenia, and specific sections of glutamate deal with suicide and restless leg syndrome.

Despite the progress that has been made, there is much more to discover and analyze. Once more data comes out and more possible loci are found, scientists will be able to put more pieces of the puzzle together. This sounds like a worthy cause to look into because finding out if the trait is genetic will be a step in handling it more effectively or possibly eliminating it completely. Less stress and worry for the affected parties will mean a more peaceful society and a better well-being for everyone.