Pollen tube through wind, water or pollinators. The last step before fertilization is the growth of the pollen tube to transfer non-motile sperm to the protected egg. Pollen tubes are unique to plants and their structure had evolved over plant history. The pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists. Pollen is produced by the stamen, the male reproductive organ of the flower. Each pollen grain contains a vegetative cell, and a generative cell that divides to form two sperm cells. The pollen is delivered by the opening of anthers for
Bacillus spore morphogenesis and germination holin family about 90 amino acyl residues in length and exhibit 3 transmembrane segments (TMSs). A representative list of homologous proteins, found only in "Bacillus" species, is available in the Transporter Classification Database. 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