ฮf you are a man wanting to improve your fertility, here are some basic things to consider/look into ๐
First, understand that spermatogenesis begins with spermatogonia (stem cells located along the basement membrane of the seminiferous tubules).
There are two main types:
-Type A (which divide mitotically to maintain the stem cell population)
and
-Type B (which differentiate to continue the process).
Type B spermatogonia undergo mitotic division to produce primary spermatocytes.
Each primary spermatocyte then duplicates its DNA during the pre-meiotic S phase, resulting in chromosomes with two sister chromatids, before entering meiosis I.
In meiosis I, the homologous chromosomes separate, forming two secondary spermatocytes.
These secondary spermatocytes quickly undergo meiosis II, where the sister chromatids separate, yielding four haploid spermatids.
The final phase, called spermiogenesis, transforms these spermatids into mature spermatozoa.
So there are 3 main stages in spermatogenesis, spermatogonial proliferation, meiosis and spermatid ,aturation.
Now, spermatogenesis is driven by 3 main hormones of the hypothalamic-pituitary-gonadal (HPG) axis:
-Testosterone
-Follicle-stimulating hormone (FSH)
-Luteinizing hormone (LH)
Here are some more details on this:
-Hypothalamus, releases gonadotropin-releasing hormone (GnRH) (a decapeptide synthesized by neurons) in pulses (GnRH is released in discrete bursts every 60-120 minutes, a process thatโs kisspeptin, neurokinin B and dynorphin, besides certain feedback loops (faster pulses favor LH, slower favor FSH).
-The pituitary gland releases FSH that drives the initial expansion of spermatogonia (it acts on Sertoli cells in the seminiferous tubules and stimulates them to produce androgen-binding protein (ABP) and secrete inhibin B) and early spermatogenesis (up to spermatocyte stage).
It also releases LH that drives testosterone synthesis by stimulating cholesterol uptake and its conversion to testosterone via the steroidogenic acute regulatory protein (StAR) and enzymes like CYP11A1 and 3ฮฒ-HSD in the Leydig cells in the testicular interstitial.
-The testes produce testosterone that diffuses into seminiferous tubules, binding androgen receptors (AR) on Sertoli cells.
Notes:
1. Sertoli cells are derived from the epithelial cells of the developing testes during embryogenesis, found inside the seminiferous tubules of the testes and form a layer lining the tubules, surrounding and interacting with germ cells (the cells that become sperm).
2. Leydig Cells are located in the interstitial space (the area between the seminiferous tubules) of the testes, produce testosterone under LH control (via cAMP/StAR pathway), diffusing it into the tubules to support Sertoli-germ cell interactions.
3. Germ cells are the precursors that develop into mature sperm.
Some basic tests that you can get done to assess your fertility status:
-Semen analysis (sperm count, motility and morphology)
-Total testosterone
-Free testosterone
-SHBG
-Follicle-stimulating hormone (FSH)
-Luteinizing hormone (LH)
-Scrotal ultrasound
-Genetic testing (a karyotype or Y-chromosome microdeletion test)
Egg freezing costs $15-20k and doesn't guarantee anything. You can invest that same money into optimizing your metabolic health and increase your odds of conceiving naturally by 3-10x.
One is a gamble. One is an investment.