The nuclear material does not undergo uniform morphological changes during spermiogenesis
, as either the central zone or the periphery can be the first to condense (Chevailler 1970).
Month N Regression Recrudescence Spermiogenesis
February 1 0 1 0 March 14 0 10 4 April 25 1 2 22 May 28 0 2 26 June 14 2 0 12 July 9 8 0 1 August 8 6 1 1 September 1 0 1 0 October 5 1 4 0 Table 2.
The first males to exhibit spermiogenesis
were observed in April (2/15) = 13%.
The study conducted using mouse model showed that mice lacking a protein called meiosis expressed gene 1, or MEIG1, were sterile as a result of impaired spermiogenesis
- the process that encompasses changes in the sperm head and the formation of the tail.
Since the distal centriole gave rise to the sperm axoneme during spermiogenesis
, it is logical to suppose that the proximal centriole that is inherited by the embryo could cause aberrant mitosis as both are derived from the same mother centriole in spermatids.
Ultrastructural observations of spermatozoa and spermiogenesis
in Wandella orana Gray, 1994 (Araneae: Filistatidae) with notes on their phylogenetic implications.
The anterior head of the mature spermatozoon is covered by an acrosomal membrane, which was derived from the spermatid's Golgi apparatus during spermiogenesis
defective chromatin condensation during spermiogenesis
that involves defective protamination and insufficient chromatin packaging (35, 42); 3.
In early recrudescence, primary spermatocytes predominate, whereas in late recrudescence, secondary spermatocytes and spermatids are most abundant; (3) Spermiogenesis
, lumina of the seminiferous tubules are lined by clusters of sperm or metamorphosing spermatids.
The annulus of the mouse sperm tail is required to establish a membrane diffusion barrier that is engaged during the late steps of spermiogenesis
," Biology of Reproduction 82(4): 669-678.
Two stages were noted in the testicular cycle: (1) spermiogenesis
(= sperm formation), in which the seminiferous tubules were lined by clusters of sperm or clusters of metamorphosing spermatids; and (2) regressed, in which the seminiferous tubules were reduced in size and contain mainly spermatogonia and interspersed Sertoli cells.
, the process of differentiation of haploid germ cells from round to elongated spermatids, takes another 7-14 days in rats and 8-17 days in humans.