Spermatocyte

[3] At puberty, spermatogonia located along the walls of the seminiferous tubules within the testis will be initiated and start to divide mitotically, forming two types of A cells that contain an oval shaped nucleus with a nucleolus attached to the nuclear envelope; one is dark (Ad) and the other is pale (Ap).

[4] Type B cells will move on to the adluminal compartment (towards the inner region of tubule) and become primary spermatocytes; this process takes about 16 days to complete.

[6] The formation of primary spermatocytes (a process known as spermatocytogenesis) begins in humans when a male is sexually matured at puberty, around the age of 10 through 14.

LH promotes Leydig cell secretion of testosterone into the testes and blood, which induce spermatogenesis and aid the formation of secondary sex characteristics.

[1] In the following table, ploidy, copy number and chromosome/chromatid counts listed are for a single cell, generally prior to DNA synthesis and division (in G1 if applicable).

These damages can arise by the programmed activity of Spo11, an enzyme employed in meiotic recombination, as well as by un-programmed breakages in DNA, such as those caused by oxidative free radicals produced as products of normal metabolism.

[9] Homologous recombinational repair (HRR) of double-strand breaks occurs in mice during sequential stages of spermatogenesis but is most prominent in spermatocytes.

[11] Because of their elevated DNA repair capability, spermatocytes likely play a central role in the maintenance of these lower mutation rates, and thus in the preservation of the genetic integrity of the male germ line.

[13] Mutations in Mtap2, a microtubule-associated protein, as observed in repro4 mutant spermatocytes, have been shown to arrest spermatogenesis progress during the prophase of meiosis I.

These mutations involve double strand break repair impairment, which can result in arrest of spermatogenesis at stage IV of the seminiferous epithelium cycle.

However, during the 1990s and 2000s researchers have focused around increasing understanding of the regulation of spermatogenesis via genes, proteins, and signaling pathways, and the biochemical and molecular mechanisms involved in these processes.

These unique traits allow researchers to study the force created by the spindle poles to allow the chromosomes to move, cleavage furrow management and distance segregation.