Among their many functions, macrophages in mouse testes guard sperm against attacks by other immune cells. 

Questions about how E. coli evolves; spermatids in a dish; fighting bacteria with virus-like molecule; what drives metastasis; antibodies fight Ebola in monkeys

Researchers devise a technique for creating gametes from murine embryonic stem cells.

Increasing the expression of two genes from non-Y chromosomes restores spermatogenesis in male mice that lack Y chromosomes.

With the deletion of a single gene, female Japanese rice fish can produce sperm. 

A missing transcription factor puts an early end to sperm production in mice.

Children with obese fathers show epigenetic changes that may affect their health.

Researchers create early stage sperm cells from induced pluripotent stem cells, raising hopes that infertile men could be fathers.

A small molecule that inhibits a protein important for chromatin organization can cause reversible sterility in male mice.