Fist batch of oral reports (For Dec. 22-25, 2021)

Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by Ed Lorenzo Palacol -
Number of replies: 7

Good day everyone! Attached below is the link to our report for our article, "Spermiogenesis defects in human: detection of transition proteins in semen from some infertile men" by S. Becker, Y. Soffer, L. M. Lewin, L. Yogev, L. Shochat & R. Golan (2008).

https://youtu.be/5VfbT-Eu69I

Don’t hesitate to comment down below any questions and comments you may have for our presentation 😊. Have a great Christmas, everyone!

Members: 

PALACOL, Ed Lorenzo 

PUNGTILAN, Ma. Kristina

SANCHEZ, Lizzie Anne 

In reply to Ed Lorenzo Palacol

Re: Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by Regina Abigail Santos -
Hello, Lizzie, Edzo, and IA!

I am Regina from Group 6.

We commend the group for an impressive presentation! It is well-explained and concise! Your group also uncovered additional concepts about spermatogenesis, which is very helpful and fascinating! As you said, the study has established the method for detecting the presence of TP1 and TP2 in a human ejaculate. Do you think this method can be used for diagnostic tests for male infertility? Also, are there TP mutations discovered related to the absence of either or both TPs and abnormal chromatin condensation?
In reply to Regina Abigail Santos

Re: Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by Lizzie Anne Sanchez -
Hi Reg! Thank you for the very interesting questions. To answer your first query: The detection of transition proteins in semen samples seems to be a promising diagnostic test for male infertility. This, however, was beyond the scope of the study. It aimed only to establish a method for detecting TPs in ejaculates, which has never been done before as it was only studied in testicular spermatids. The study was not able to establish a relationship between TP expression and fertility although results showed that normal human semen samples would mainly contain condensed haploid nuclei, corresponding to normal healthy spermatozoa. Becker and colleagues (2010) did not quantify TP expression in normal and abnormal semen samples which may be used to establish a threshold value for TP expression that would denote infertility. We recognize that research on the association between TP expression in semen and infertility is still in its infancy but with further research on this subject area (e.g. quantifying TP expression in the semen of patients with varying diagnoses) it may be possible that diagnostic testing for infertility may also include analysis of TP expression in semen samples.

Thank you again and happy holidays!! :)
In reply to Regina Abigail Santos

Re: Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by Ed Lorenzo Palacol -
Oh, and regarding your 2nd question, Reg. Yes, there have indeed been some mutations discovered in relation to TPs. As an example, Miyagawa et. al. (2013) analyzed transition protein mutations in human males. They concluded through their study that some infertile men had a deletion of 15 nucleotides in the TP1 gene. It turns out that this deletion reduces TP1 expression, effectively increasing the infertility of the patients significantly. This shows that some mutations have in fact shown to be one of the causes for the loss and absence of gene expression in TP synthesis.
Other researchers have also explored TP gene mutations further by inducing the mutations in labs. Zhao et. al. (2001) conducted a targeted disruption of the TP2 gene in mice, and in their findings have found that a mutation rendering the TP2 gene inactive would not necessarily cause conformational changes in the sperm morphology. Instead, it would have a more “indirect” effect since TP2 is needed for the processing of protamine 2 (P2) which is essential in helping complete proper chromatin arrangement. Thus, a mutation leading to the absence of TP2 would cause abnormal processing of P2, which in turn will disrupt the proper completion of chromatin condensation in sperm. The resulting sperm would then likely be infertile.

Feel free to read more from their studies:
Miyagawa, Y., Nishimura, H., Tsujimura, A., Matsuoka, Y., Matsumiya, K., Okuyama, A., ... & Tanaka, H. (2005). Single‐nucleotide polymorphisms and mutation analyses of the TNP1 and TNP2 genes of fertile and infertile human male populations. Journal of andrology, 26(6), 779-786.
Zhao, M., Shirley, C. R., Yu, Y. E., Mohapatra, B., Zhang, Y., Unni, E., Deng, J. M., Arango, N. A., Terry, N. H., Weil, M. M., Russell, L. D., Behringer, R. R., & Meistrich, M. L. (2001). Targeted disruption of the transition protein 2 gene affects sperm chromatin structure and reduces fertility in mice. Molecular and cellular biology, 21(21), 7243–7255. https://doi.org/10.1128/MCB.21.21.7243-7255.2001
In reply to Ed Lorenzo Palacol

Re: Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by Lydia LEONARDO -
Thank you for this interesting presentation. My questions are:
1. There was mention in your report of round spermatids successfully fertilizing eggs. Can you elaborate on this?
2. How did the authors propose to relate TPs with varying degrees of spermatogenic defects?
Thank you.
In reply to Lydia LEONARDO

Re: Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by Ma Kristina Pungtilan -

Hello Ma’am Leonardo,

Thank you very much for your interest in our presentation. Here are the answers for your queries:

1. There was mention in your report of round spermatids successfully fertilizing eggs. Can you elaborate on this?

In the paper, it was hypothesized that transition proteins play an important role for the production of normal spermatozoa. However, regardless of the presence of transition proteins, it may still be possible for unconsensed spermatozoa (even round spermatids) to successfully fertilize eggs. This is through intracytoplasmic sperm injection (ICSI), a method of assisted reproduction wherein a very thin needle is used to inject a sperm directly into the cytoplasm of a harvested egg (Lyttleton, 2013). 

Meanwhile, one of the first few reports on successful fertilization using round spermatids was done using mouse spermatids. In the study performed by Ogura and colleagues (1994), electrofusion method was applied to facilitate the fusion of the mouse oocytes and the young sperms. It was therefore concluded that round spermatids also have reproductive potential and that most postmeiotic events involved in sperm formation and maturation may have evolved just to ensure delivery of the male haploid nuclei into oocytes. A year after this paper was published, Tesarik and his team (1995) conducted a sperm-injection program wherein round spermatids from semen of infertile men were microinjected into the ooplasm. In this endeavor, 36% of all oocytes were successfully fertilized. Studies such as those previously mentioned offer positive prospects for the treatment of male infertility due to defects in the postmeiotic proccesses involved in the production of normal spermatozoa.

REFERENCES:

Lyttleton, J. (2013). Assisted reproduction technology and in vitro fertilization. Treatment of Infertility with Chinese Medicine, 334–342. doi:10.1016/b978-0-7020-3176-2.00009-8 

Ogura, A., Matsuda, J., & Yanagimachi, R. (1994). Birth of normal young after electrofusion of mouse oocytes with round spermatids. Proc Natl Acad Sci, USA, 91: 7460-2.

Tesarik, J., Mendoza, C., & Testart, J. (1995). Viable embryos from injection of round spermatids into oocytes. N Engl J Med 333:525.


2. How did the authors propose to relate TPs with varying degrees of spermatogenic defects?

Since the scope of their study was simply the detection of TPs in human ejaculates, their recommendations for the improvements of the study will then include TP quantification. As in the results, no clear relationship was drawn between the degree of spermatid immaturity and TP expression. In addition, cells of this type were then found in semen from patients with a wide variety of diagnoses, including nonobstructive azoospermia, severe to extreme cases of oligozoospermia, asthenozoospermia and teratozoospermia; all of which have no clear relationship established to any diagnostic category.

Furthermore, it was stated that in order to draw conclusions of TP expression with multiple spermatogenic defects, further research is necessary so as to quantify the appearance of TPs in spermatids of patients with different diagnoses.

In reply to Ed Lorenzo Palacol

Re: Bio 133 LEC2 (TF 10-11:30 AM) — Spermiogenesis

by John Patrick Bisquera -
Hi Edzo, IA, and Lizzie!

I am Patrick from Group 1 (Agustin, Bisquera, Punzalan). First of all, we want to commend you for your interesting and thought-provoking presentation. Your report demonstrated the promising potential of using the presence of transition proteins in male semen to assess their fertility. In connection with Regina’s inquiry, our group would like to know how this method would compare with other diagnostic tests in determining male infertility. Would it be as accurate as the other tests? Moreover, would it also be a more cost and time-efficient method to assess male fertility? Thank you and Merry Christmas!