Chemotactic compounds hormone Progesterone,  made by the cumulus cells, might trigger the release of Protein kinase A from the sperm cell membrane, & allowing it to activate the sperm-specific cation CatSper channels would facilitate the transfer of calcium ions into the sperm, where they would cause exocytosis of the acrosome

TLS Online TPP Program

#Id: 409

#Unit 2. Cellular Organization

H3.3 is expressed throughout the cell cycle, in contrast to most histones that are expressed during S phase during replication.

TLS Online TPP Program

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#Unit 2. Cellular Organization

H3.3 is available for assembly at any time in the cell cycle, and is incorporated at sites of active transcription, where nucleosomes become disrupted.

TLS Online TPP Program

#Id: 411

#Unit 2. Cellular Organization

H3.3 is often referred to as a “replacement” histone.

TLS Online TPP Program

#Id: 412

#Unit 2. Cellular Organization

The H2A variants are the largest and most diverse family of core histone variants.

TLS Online TPP Program

#Id: 413

#Unit 2. Cellular Organization

H2AX is normally present in only 10%–15% of the nucleosomes in multicellular eukaryotes

TLS Online TPP Program

#Id: 414

#Unit 2. Cellular Organization

H2AX subtype is has a C-terminal tail that is distinct from the canonical H2A, characterized by a SQEL/Y motif at the end.