Friday 22 April 2011 Definition: The spermatid is the haploid
male gametid that results from division of secondary
spermatocytes. As a result of meiosis, each spermatid contains
only half of the genetic material present in the original
primary spermatocyte. Spermatids are connected together by
cytoplasmic material and have superfluous cytoplasmic material
around their nuclei. When formed, early round spermatids must
undergo further maturational events in order to develop into
spermatozoa, a process termed spermiogenesis (also termed
spermeteliosis). The spermatids begin to grow a living thread,
develop a thickened mid-piece where the mitochondria become
localised, and form an acrosome. Spermatid DNA also undergoes
packaging, becoming highly condensed. The DNA is packaged
firstly with specific nuclear basic proteins, which are
subsequently replaced with protamines during spermatid
elongation. The resultant tightly packed chromatin is
transcriptionally inactive. Spermatidogenesis is the creation of
spermatids f