Talk:Spermatozoa Development

A comparative view of sperm ultrastructure. Fawcett DW. Biol Reprod. 1970 Jun;2:Suppl 2:90-127. PMID: 5521054

http://www.biolreprod.org/content/2/Supplement_2/90.long

Spermatogenesis-Specific Features of the Meiotic Program in Caenorhabditis elegans (excellent meiosis images)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2720455/?tool=pmcentrez

All You Wanted to Know About Spermatogonia but Were Afraid to Ask http://www.andrologyjournal.org/cgi/reprint/21/6/776

Microgravity promotes differentiation and meiotic entry of postnatal mouse male germ cells. Pellegrini M, Di Siena S, Claps G, Di Cesare S, Dolci S, Rossi P, Geremia R, Grimaldi P. PLoS One. 2010 Feb 4;5(2):e9064.

PMID: 20140225

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2847216/?tool=pubmed

"During mammalian spermiogenesis, histones at the onset of the differentiation process are gradually replaced by transition proteins and protamines (14,22) and although the replacement is almost complete in most species, in humans ~15% of the mature sperm chromatin remains associated with histone variants"

Sequence-specific packaging of DNA in human sperm chromatin. http://www.ncbi.nlm.nih.gov/pubmed/3576213

"The DNA in human sperm chromatin is packaged into nucleoprotamine (approximately 85%) and nucleohistone (approximately 15%). Whether these two chromatin fractions are sequence-specific subsets of the spermatozoon genome is the question addressed in this report. Sequence-specific packaging would suggest distinct structural and functional roles for the nucleohistone and nucleoprotamine in late spermatogenesis or early development or both. After removal of histones with 0.65M NaCl, exposed DNA was cleaved with Bam HI restriction endonuclease and separated by centrifugation from insoluble nucleoprotamine. The DNA sequence distribution of nucleohistone DNA in the supernatant and nucleoprotamine DNA in the pellet was compared by cloning size-selected single-copy sequences and by using the derived clones as probes of nucleohistone DNA and nucleoprotamine DNA. Two clones derived from nucleohistone DNA preferentially hybridized to nucleohistone DNA, and two clones derived from nucleoprotamine DNA preferentially hybridized to nucleoprotamine DNA, which demonstrated the existence of sequence-specific nucleohistone and nucleoprotamine components within the human spermatozoon."