• Why, oh, why can't life be less com­pli­cated?

    by Christoph — It could all be so easy! Take a bac­te­r­ial cell, say, a sin­gle E. coli cell with all its ~4,300 genes nicely strung like pearls on the neck­lace of its sin­gle cir­cu­lar chro­mo­some. Present this E. coli cell with some­thing to eat and it starts grow­ing and, while grow­ing, repli­cates its chro­mo­some start­ing at oriC, the unique repli­ca­tion ori­gin. When the cell has reached twice its orig­i­nal size and now con­tains two chro­mo­somes, the cell di­vides...

  • Ploidy Re­dux

    by Elio — We re­cently posted a short piece on the term 'ploidy' as it ap­plies (or not) to prokary­otes. Dana Boyd pointed out that in prokary­otes the term refers to sets of iden­ti­cal chro­mo­somes, un­like in eu­kary­otes, where each chro­mo­some of a set is usu­ally dif­fer­ent. The dis­tinc­tion seems cru­cial enough to war­rant fur­ther ex­pli­ca­tion.

  • Of Terms in Bi­ol­ogy: Bac­te­r­ial Ploidy

    by Elio — Ploidy is not a term that has much cur­rency in bac­te­ri­ol­ogy, but it does make an ap­pear­ance once in a while. Ploidy, as per the dic­tio­nary, is the num­ber of chro­mo­somes per cell. It's a term widely used for cells that are gen­er­ally un­in­u­cle­ated, such as our ga­metes and our so­matic cells. The prob­lem here is that bac­te­ria are not con­sis­tently un­in­u­cle­ated.