Spermatogenesis is the process by which sperm cells are produced. It involves the division and differentiation of germ cells within the seminiferous tubules of the testes. High temperatures can damage spermatogenesis, particularly affecting primary spermatocytes. Vitamin E and A both play roles in spermatogenesis, with deficiencies leading to disrupted or incomplete sperm production and potential infertility. Maintaining proper vitamin levels and avoiding high temperatures are important for normal spermatogenesis.

1. Effect of heat and vitamin deficiency on spermatogenesis
Spermatogenesis
Spermatogenesis is a process of division and differentiation by which spermatozoa are
produced in seminiferous tubules. Seminiferous tubules are composed of somatic cells (myoid
cells and Sertoli cells) and germ cells (spermatogonia, spermatocytes, and spermatids). Activities
of these three germ cells divide spermatogenesis into spermatocytogenesis, meiosis, and
spermiogenesis, respectively. Spermatocytogenesis involves mitotic cell division to increase the
yield of spermatogenesis and to produce stem cells and primary spermatocytes. Meiosis involves
duplication and exchange of genetic material and two cell divisions that reduce the chromosome
number to haploid and yield four spermatids. Spermiogenesis is the differentiation without
division of spherical spermatids into mature spermatids which are released from the luminal free
surface as spermatozoa.
Temperature
Effect of temperature on spermatogenesis
The testis of domestic animals are susceptible to damage if the body temperature rises
above normal which could occur due to raised environment temperature. If experimentally only
testicular temperature is increased temperature of whole body increases rapidly causing the
stimulation of the thermoregulatory mechanism of whole body.Exposure of the bull to heat stress
(extreme environmental temperature) tends to damage the primary spermatocytes while the
spermatids and spermatozoa are also sensitive to heat stress.Testicular temperature must be 3-
4℃ lower than the body temperature for normal spermatogenesis to occur. Critical temperature
for the inhibition of spermatogenesis varies from species to species, it is nearly 31℃ for equines
under continuous exposure. Higher temperature alters the scrotal thermoregulatory mechanism,
this will lead to the damage of primary spermatocytes, spermatids, and spermatozoa.Exposure of
the testis to cold seems to be less damaging. Even if the testicular temperature decreases, the
animal usually maintains a scrotal thermoregulation by pulling testis up close to the body.Germ

2. cell degeneration occurs throughout spermatogenesis; however, the greatest impact of
temperature occurs during spermatocytogenesis because seminiferous epithelium is sensitive to
elevated temperature.
In case of human, hot bath and tight underwears reduces sperm concentration and semen
volume due to increased scrotal temperature and poor scrotal thermoregulatory process.
Main anatomical features for thermoregulation:
 Thin scrotal skin, often hairless, lots of sweat glands
 Tunica dartos and cremaster muscle
 Pampiniform plexus (countercurrent heat exchange)
 Absence of fat
Vitamin E
Role of Vitamin E in spermatogenesis
Vitamin E plays a key role in the maintenance, viability & survivality of the spermatid
population and in allowing epithelial epididymal cells to acquire their fully differentiated
structural appearance. In the epididymis, vitamin E plays a role in the structural differentiation of
principal cells along the entire epididymis, whereas, in the case of clear cells, its role is region-
specific.
Effect of deficiency of Vitamin E on spermatogenesis:
Due to deficiency of vitamin E , Spermatogenesis remain incomplete; the most advanced
cell type is predominantly spermatids. However, many of these cells, as well as earlier
spermatids, appeared to undergo degeneration, large pale areas in their nuclei,
disrupted acrosomes, and a cytoplasm with uncharacteristic organelles are observed under
electron microscope. Multinucleated cells, characterized by their chromatoid bodies as
spermatids, are oftenly seen in the seminiferous tubule lumen.In the epididymis, vitamin E
deficiency resulted in principal, narrow, and apical cells that showed a poorly developed

3. secretory and endocytic apparatus. On the other hand, clear cells shows a highly developed
endocytic apparatus in the cauda region only, whereas in the caput and corpus regions, endocytic
apparatuses are small and undifferentiated.
Administration of vitamin E to the diet restors a normal appearance to both the testis and
the epididymis, which indicates that the effects on these tissues are reversible.
Vitamin A
Role of Vitamin A in Spermatogenesis:
Vitamin A regulates germ cell differentiation and it may lead to the generation of both
the cycle of the seminiferous epithelium and the spermatogenic wave.
Effect of deficiency and excess of Vitamin A
Degeneration of the seminiferous tubules and reduction of the germinal epithelium is
observed in cases of vitamin A deficiency. On the other hand, hypervitaminosis A causes
testicular degeneration and suppresses or delay spermatogenesis. However, the exact role of
vitamin A in the process of spermatogenesis is still unknown.
Prolonged administration of Retinol acetate induces almost complete cessation of
spermatogenesis and produces alterations in the cytoplasm of Leydig cells.
The changes observed can be reversed 12 weeks after stopping administration.
Conclusion:
Total sperm concentration, sperm concentration per ml. markedly reduced. Concentration of
immature & abnormal sperm concentration increased, ejaculatory process delayed, libido is
hampered causing sub-fertility, infertility or sterility.