natgeo Video by @joelsartore | The Ural owl’s four-foot wingspan allows it to glide gracefully from perch to perch as it scans the ground for smaller animals to hunt. Any surplus food the owl catches is stored either in its nest or in nearby spaces for later. Males of this species claim their territory by singing from their perch, and mates can be heard dueting during courtship. These beautiful birds of prey live in deciduous forests in Northern Europe through northern Russia and Siberia all the way to Korea and Japan.
Ready, Set, Sperm
Male infertility contributes to around half of infertility cases. There are many reasons why men can be infertile, including the production of low-quality sperm, low sperm count or low levels of testosterone. Polycomb Repressive Complex 1 (PRC1) is a protein complex known to be involved, as its name suggests, in silencing the production of certain proteins from their gene. However, in a mouse model, PRC1 was found to change once males reached reproductive age and activate certain genes responsible for triggering fertile sperm. The change in PRC1 involved the addition of another protein called Sall4 (pictured in green in a testicular section) to initiate the timely production of fertile sperm. When PRC1 is disrupted in mice, they’re unable to produce healthy sperm nor, therefore, reproduce. This finding will help researchers to dig deeper into genetic factors affecting infertility.
Written by Katie Panteli
- Image from the Namekawa Research Lab, Cincinnati Children’s Hospital
- Division of Reproductive Sciences, Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Image copyright held by the original authors
- Research published in Genes & Development, September 2017