The fate of sperm centrioles

• Centrioles have many roles in the cell, one of which is as a microtubule-organizing center, which is important for cell migration and division.
• Many organisms, including humans, can undergo mitosis without centrioles, so they’re not essential for that.
• On the other hand, the primary function of centrioles is to form the base of cilia, which are used by animal cells for both motility and signaling. Since plants don’t have cilia, they don’t require centrioles.
• Similarly, sperm cells require functional flagella to reach the oocyte and have motility following fertilization. Therefore, the presence and proper function of centrioles in sperm is crucial.
• There are some interesting animal cells that can divide correctly without centrioles – microtubules can form an organizing center by other means (as they do in plants and diatoms).
• However, establishing polarity in divided animal cells without centrioles is an issue – in other words, positional cues from neighboring cells and how it should grow are lost.
• Some centriole-like proteins are small enough to miss, so scientists may have yet to identify them as such. This suggests that centrioles co-evolved with cilia as there are no centrioles in organisms that lack cilia.
• The fact that there are organisms that can evolve cilia from scratch suggests that there may be smaller proteins that could function as centrioles but are not as complex.
• If a centriole-like protein is small enough, scientists may have yet to identify it as such.
• It is possible that, after fertilization in humans, the sperm centriole gives rise to the first centriole of the zygote.
• Studies suggest that the sperm centriole is selectively destroyed in the first mitotic division, and it doesn’t contribute to centrosome formation, which controls cell division.
• The exact timing and mechanism of centriole removal in the zygote are not well understood, and there is still some debate on whether the sperm centriole is retained or eliminated.
• Some studies suggest that the loss of the sperm centriole is critical for the prophylaxis of paternal mitochondria and the correct formation of the centrosome.
• The role of the sperm centriole after fertilization may be limited, and it may not be necessary for embryonic development beyond the first cell division.
• However, the role of the sperm centriole in human embry

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• The webpage is titled “Stages of foetus development as per Garva Upanisheda, carved in Sri Varamoortheeswarar Temple, Ariyathurai, Tamil Nadu, around 3000 BC.”
• The webpage features a picture of a rock carving in Sri Varamoortheeswarar Temple in Tamil Nadu that depicts the stages of foetus development as per Garva Upanisheda.
• The caption of the picture states that the temple is believed to be 5000-6000 years old.
• The webpage is from 3 years ago and was posted on Reddit’s r/hinduism community, where it received 482 points.
• One commenter asks for the source of the images, which leads to another commenter sharing two links about the carving.
• One link is from My India My Glory and features an article on how ancient Indians knew the science of fertilization without microscopes. The article cites Garbha Upanishad as a text that contains knowledge about fertilization. However, some comments point out that the source is not a peer-reviewed academic paper and does not provide any sources to back its claims.
• Another link shared is in Tamil and features images of the temple and the carving. However, a commenter notes that this carving is not in the temple at the address shared in the link.
• Some comments debate the validity of the claims about the carving and question the sources presented.
• One commenter notes that if the ancient Indians had knowledge of fertilization and foetal development without microscopes, it would be interesting to know what they knew about the fate of sperm centrioles.
• Another commenter speculates that ancient Indians may have known about foetal development through still births and surgeries similar to C-sections.
• One commenter shares a Medium post by Subhash Kak on Garbha Upanishad and how life begins.
• Commenters discuss the importance of preserving heritage and the knowledge of ancient civilizations like India.

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• Dr. Ranjith Ramasamy is a male infertility specialist who works as the Director of Reproductive Urology and an Associate Professor in the Department of Urology at the University of Miami.
• He specializes in the treatment of disorders of male infertility and sexual dysfunction.
• He completed his Urology residency at Weil Cornell Medical College and New York-Presbyterian Hospital and a National Institutes of Health-sponsored fellowship at Baylor College of Medicine.
• He has published over 200 manuscripts in peer-reviewed journals and several book chapters on male reproductive medicine and surgery, serving on the editorial board of Andrology, Asian Journal of Andrology and Urology, as well as being an editorial reviewer for medical journals such as Journal of Urology, Fertility and Sterility, European Urology, and British Journal of Urology.
• Dr. Ramasamy hosted an AMA on Reddit on July 17th, 2019, discussing male infertility and how to achieve a successful pregnancy.
• He answered several questions from Reddit users on topics related to male infertility and treatments.
• Some of the topics he discussed were:
  • Diagnosis of male infertility, including sperm analysis, prognosis, and treatment options for male infertility.
  • Evaluation of the cause of male infertility.
  • Treatment options for male infertility, including surgery for varicoceles, medications to improve testosterone levels.
  • The natural variability of sperm counts over time and how it relates to male infertility.
  • Prednisone sometimes yielding good results with motility by decreasing scarring at the site of anastomosis.
  • Understanding that conception chances are naturally low even with some progress with male infertility treatment.
• Dr. Ramasamy suggests proceeding with IVF if couples are interested in a pregnancy ASAP.
• Dr. Ramasamy has appeared on several TV programs discussing treatments for male infertility, including NBC 16 Indiana and ABC 8 Illinois.
• Dr. Ramasamy’s website is www.ranjithramasamy.com.
• Dr. Ramasamy’s Instagram account is https://www.instagram.com/ranjith.ramasamy/.

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• Each sperm carries the same DNA, but they are not all the same.
• Siblings who come from the same parents often look different, which means that each sperm has different genetic makeup.
• The ladle conditions the sperm are in, including the fluid that the semen is mixed with, can have an influence on the genes of the sperm. That effect is called epigenetics.
• Epigenetics partially explains why identical twins don’t look identical.
• There is no clear identification of what makes one sperm better or faster than others in fertilizing the egg.
• Factors such as the semen fluid, which creates a pathway for strong sperms, help propel efficient sperm into the privileged pathway.
• The cervix produces different fluids and only the strong enough sperm to swim hard gets on the pathway.
• The conditions determine which sperm can bind with the egg.
• The first sperm to get into the egg also causes the egg membrane to undergo a lot of changes, which prevent other sperms from getting in.
• Even though sperm contains the same genes and chromosome as an egg, they are very different.
• Sperm and egg are gametes containing only 23 chromosomes, and are not like any other cells in the human body, which have 23 pairs of chromosomes.
• When the respective chromosomes pair after fertilization, the offspring has those genes, with one chromosome from the mother and one from the father.
• Each chromosome lines up with its pair, and the chromosomes are swapped with each other at different points along the pair, creating approximately 8-million different chromosome combinations.
• Many genes on chromosome pairs may end up being similar, so the effective diversity is somewhat diminished.
• Counting combinations, without any mutation or crossover of the genetic material within the chromosome, the child’s DNA has 70 trillion possible arrangements.
• It’s believed that the centriole in the sperm helps facilitate cell division. The centriole is eventually destroyed by the egg after fertilization.
• There is no mention of what happens to the centrioles of the other sperm that do not fertilize the egg.

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• Argues against the 64 or 72 day theory of sperm maturation reset after ejaculation as sperm that matured 64 or 72 days ago still gets ejaculated instead of only the immature.
• Says new mature sperm gets produced every day that some of these could be matured and ejaculated without fully resetting the maturation cycle.
• The theory of sperm maturation reset has no scientific basis and the benefits reported from semen retention happen before reaching 64 days, which could be explained by the constant production of mature sperm.
• A commenter mentioned that it’s at around 60 days where one could shift into the next gear of steadiness.
• Elaboration on that is experiencing brighter colors and seeing life differently, having a sudden increase in energy, feeling an exciting feeling with butterflies in your stomach like something great is about to happen, having attraction increase with aggressive behavior, expanding the mind, and feeling magical energy that sometimes creates shivers.
• Another commenter said that masturbation or porn kills attraction or vibe, and can create a mismatch with the number of women around them becoming attracted being less than what they want.
• Discusses “Testicular germ cells” that can mimic embryonic stem cells and become any cell in the body. These are referred to as spermatogonial cells, and are the source of the body’s supply of sperm.
• The mature cells that become stem cells could then be distributed throughout the body where needed to mature into new cells such as bones, muscles, and nerves.
• There was a discussion on mesenchymal stem cells that presumably sperm cells can morph into.
• The Website “Vasectomy-information.com” has a post that says that testicular germ cells appear to mimic embryonic stem cells and become pluripotent stem cells.
• In Eastern arts it is believed that germ cells are actually the foundation of both the blood and semen, and hence the body’s lifeforce. It concludes with the notion that ejaculating does not increase and is believed to decrease the body’s vitality.

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• Male factor infertility, importance in blast formation, embryo development, recurrent pregnancy loss / miscarriages, unexplained infertility, IVF, and capability of eggs to repair damage discussed. [Title]
• Estimated that 50-70% cases of infertility issues are male factor related.
• Sperm DNA integrity is a must to do a test and should be included in the primary workup of every couple struggling with conceiving or recurrent pregnancy loss.
• Sperm analysis alone is a poor predictor of fertility for males.
• Sperm DNA fragmentation is measureable by breaks in DNA strands.
• The current WHO guidelines included sperm from males that have fathered children, but does not tell us how many miscarriages, chemical pregnancies, stillbirths, time to pregnancies their partners had to endure prior to having their living child.
• Lower the parameters of sperm analysis, the longer it takes to get pregnant, the more miscarriages women suffer and so on.
• Approximately 20% of males with “normal” sperm analysis contribute to male infertility.
• Various factors such as poor diet, smoking, alcohol consumption, and varicocele can have detrimental effects on a couple’s fertility potential.
• Male progressive motility analysis correlates with percentage of nonfunctioning sperm mitochondria.
• Mitochondrial issues can cause sperm to not make enough ATP (cell’s energy) to propel the sperm.
• Sperm DNA fragmentation negatively affects natural pregnancy (by no pregnancy, miscarriage, birth defects, and increased risk of cancer) as well as ART procedures.
• Eighty percent of couples diagnosed with unexplained infertility had DNA fragmentation of >25%.
• Recurrent pregnancy loss & “unexplained infertility” has long been “unexplained” and anything from “relaxing, to TLC to many other holistic therapies have been advised for women while very little implication to male genome in RPL which is another crucial mistake.
• In cases where a younger female workup is normal, it is even more important to look at the male workup closely.
• There have been instances of 3+ losses where women are constantly told to keep trying which has been detrimental to their mental and physical health.
• DNA fragmentation over 30% increases the risk highly for miscarriage naturally and with ART procedures, even in cases where ICSI has been used.
• Using ICSI for procedures would bypass issues because only “the best sperm possible is chosen”. We now know that this is not the case.
• Existing sperm sorting methods are not efficient and isolate sperm having high DNA fragmentation and

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• Sperm contribute multiple factors that shape embryogenesis including the seminal plasma, sperm centriole, sperm proteins, sperm RNA, sperm DNA, and its integrity, together with epigenetics.
• Male derived factors contribute much more than just the male haploid genome to the early embryo, with sperm centrioles contributing to correct fertilization and development of the early embryo.
• The paternal centriole contributes to the proper formation of the zygotic spindle and cleavage furrow in early embryonic development.
• Paternal factors can influence the female reproductive tract and post-fertilization events.
• Recent proteomic and transcriptomic studies have identified several sperm-borne markers that play important roles in oocyte fertilization and embryogenesis.
• Understanding the contributions of paternal factors can shed light on how to improve assisted reproductive techniques from an andrological perspective.
• The role of human sperm proteins to the development and epigenome of the preimplantation embryo is being studied.
• Age-associated epigenetic changes in mammalian sperm could have implications for offspring health and development.
• Sperm DNA fragmentation could influence early embryonic development.
• Sperm and seminal plasma RNAs could play a significant role beyond fertilization.
• Paternal overweight may impact sperm chromatin integrity, fertilization rate, and pregnancy outcome.
• Endocrine disrupting chemicals can affect male fertility.
• Intracellular, non-oxidative factors can activate in vitro chromatin fragmentation in pig sperm.
• RNA methylation at the maternal-fetal interface may impact implantation and placentation.
• Evaluation of sperm DNA fragmentation can be conducted using two methods: TUNEL via fluorescence microscopy and flow cytometry.

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The significance of centrioles in embryonic development

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The role of sperm centrioles in fertilization