Spermatid

The term spermatid refers to the haploidmale gametidthat 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 tail, develop a thickened mid-piece where the mitochondriabecome 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 protaminesduring spermatid elongation. The resultant tightly packed chromatinis transcriptionally inactive.

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It uses material from the http://en.wikipedia.org/wiki/Spermatid Wikipedia article Spermatid.