Y Chromosome Analysis of Horses

 

Scientists are attempting to trace the paternal line in horses by using the Y chromosome. The Y chromosome has always been difficult to study since it contains many repeating sections and palindromes. Since computer technology has made it easier to analyze it, a worldwide collection of horse DNA samples were able to be analyzed, and the ancestries of these horses were able to be traced. Horse and human history are closely linked, and humans have used stallion mediated breeding with horses due to the fact that it is easier to trace a stallion’s fertility than a mare’s. Pedigrees are used to trace horse ancestry today, but since they are done manually then only go back a few generations. With the Y chromosome analysis, however, they are able to go back many generations and examine evolutionary lineages within the horse’s paternal ancestry. This will allow horse breeders to better prevent inbreeding and maintain genetic diversity.

In my opinion, this is a very useful and unique effort. Mapping the Y chromosomes of a variety of horses in order to examine their evolutionary development and lineages on their paternal side proved to be extraordinarily beneficial. By gaining the ability to trace the genetics of horses across multiple generations, we can better keep record of particular lineages and ensure that horses with similar lineages do not breed together in order to prevent genetic defects. We can work to better conserve and enhance genetic diversity within horses. We are also able to better analyze breeding influences over time and how they connect with human history as well.

    

                         

Boys Who Smoke Could Be Harming Their Future Children's Health

 Boys Who Smoke Could Be Harming Their Future Children's Health 

    New research has found that males who smoke in their teenage years risk passing on harmful traits to their children. The study was conducted on 875 people, ages ranging from 7-50, and their fathers smoking past. Those whose fathers were smokers at some point had more problems, such as asthma. Biomarkers showed that these traits were different from those that could be passed on from maternal smoking or those who smoke themselves. This was the first human study to reveal the impact of fathers' smoking on their children. Study co-author Negusse Kitaba stated, "Early puberty may represent a critical window of physiological changes in boys. This is when the stem cells are being established which will make sperm for the rest of their lives." 

    I think it's very helpful that this finding was finally discovered because people didn't and still don't really know how harmful a father smoking can be to his kids. I had heard about smoking while pregnant affecting the child but nothing about the father. I also think it is really interesting but also makes sense that this is seen with children whose fathers smoked before or during puberty. I never thought about how their sperm cells are developed during puberty and that something like smoking can have an effect on that. Reading this article made me think why it hasn't been studied before as the whole world knows pregnant women shouldn't smoke. This finding also upsets me because I feel nowadays many young boys smoke vapes and such and therefore the following generation might not be so healthy. 

Links:

https://www.usnews.com/news/health-news/articles/2023-09-05/boys-who-smoke-could-be-harming-their-future-childrens-health

https://www.cbsnews.com/boston/news/teenage-boys-smoking-dangers-harm-future-children/

Evolution vs Older Dads

What does natural selection have against older fathers? The article Evolution is not kind to older dads found on ScienceMag looks further into the truth and reasoning of why kids born to older fathers are less likely to have children of their own.

It is a commonly known phenomenon that as dads get older, their chances of producing offspring without mutations get slimmer and slimmer, however, what is less talked about is the risk that their children then face when having offspring of their own. Some of these mutations can be harmless while others can significantly increase the risk for certain diseases. Colleagues at the University of Göttingen in Germany studied and analyzed census records from 17th and 18th century Germany, Canada and Sweden, as well as from 20th century Sweden. The study showed that in both populations, children born to older fathers had fewer kids of their own that survived past the age of 5. For each decade that a father aged, his children had around 10% fewer children of their own.

According to WebMD, studies have found that those born to fathers 45 and older were more likely to have children with mental health problems (autism, bipolar disorder, schizophrenia, and ADHD) as well as rare genetic disorders, such as dwarfism, due to an increase in mutations in an older man's sperm.

As explained in the article, the daughter of a 17th century farmer may have been cursed with a weakened immune system or a malfunctioning heart, leading to possibly an early death sentence or at least prevented her from having her own children. Being born in the 21st center, however, would dramatically increased the child's chances of a long and productive life thanks to modern medicine. The percentage of Swedish babies that survive up to 1 year of age is above 99%, whereas 200 years ago, fewer than 90% survived past 1 year.

Babies born prematurely or with birth defects are now more likely to live. Well then why do children born to older fathers still show to have fewer kids of their own that survive past the age of 5? Just because kids born to older fathers are surviving longer, doesn't necessarily mean they're able to reproduce properly when they reach adulthood. They could struggle with infertility or have a condition like autism that makes it harder to find a partner. For some it could even be a matter of choice. Parents who are at high risk to have offspring with a certain mutation might decide to adopt instead.

Don't be alarmed, the portion affected by this is still extremely low in respect to the human population. Some scientists still argue that if the reproduction of the children of older fathers is greatly decreased, harmful mutations could make their way out of our gene pool. I really look forward to the findings of new discoveries related to this topic. Maybe in the future there will be more available resources for older men to have their sperm monitored for mutations or to get their sperm frozen and preserved before they grow older than the "age of risk". If this article relates to you or your family members, don't panic, Hugh Hefner had his last child at the age of 66, and his son turned out just fine (well, debatable).

Sperm Passes on Obesity Genes from Father to Child

A new small study suggests that weight in men can affect important genes that can pass on obesity to his child. The way genes are expressed was different between men of normal weight and men who were obese, which affects gene regions linked to brain development and appetite control. It is common that an obese father has an obese child and genetics is partially responsible for this. This study analyzed how genetics plays a role in obesity by using epigenetics, "chemical mechanisms that determine whether a gene is active or dormant at certain times." Epigenetic patterns can be inhereited, but can also be altered with diet and exercise. 

There were 13 men of normal weight and 10 obese men whose sperm was studied. There was an evident difference in the DNA methylation in their sperm and it was found to be linked to genes related to appetite control. In further testing, the researchers studied a group of obese men who went through immense weight loss and found a "dramatic" difference in the DNA methylation of their sperm. In essence, not only the health of the mom matters during conception and pregnancy. 

Overall, this is helpful research because it can prevent childhood obesity and other serious health conditions related to it. Further research should be conducted because I feel there was not a large enough sample size in this experiment to support this hypothesis. It is incredible how two of the same genes can be expressed differently through different DNA methylation patterns and I think it is beneficial for geneticists to study this occurrence closely to help children become healthier from birth.