Aperture (botany) pollen grain. Aperture (botany) Apertures are areas on the walls of a pollen grain, where the wall is thinner and/or softer. For germination it is necessary that the pollen tube can reach out from the inside of the pollen grain and transport the sperm to the egg deep down in the pistil. The apertures are the places where the pollen tube is able to break through the (elsewhere very tough) pollen wall. The number and configuration of apertures are often very exactly characteristic of different groups of plants. The biggest class of plant species, the Eudicots, usually have three apertures
Bacillus spore morphogenesis and germination holin family Bacillus spore morphogenesis and germination holin family The "Bacillus" Spore Morphogenesis and Germination Holin (BSH) Family (TC# 1.E.23) is a family of proteins named after a holin in "Bacillus subtilis" described to be involved in spore morphogenesis and germination by Real et al (2005). The gene encoding this holin is "ywcE." Mutants lacking this gene or its product have spores that exhibit outer coat defects. These spores lack the characteristic striatal pattern resulting in the failure of the outer coat to attach to the underlying inner coat. Finally, the mutant spores accumulate reduced amounts of dipicolinic acid. BSH proteins average