sex life revealed

Scientists have found evidence that Giardia, an ancient protist long considered to be asexual, may have a sex life. John Logsdon and colleagues at the University of Iowa found that the protist has homologs of crucial meiotic proteins.¹

Logsdon's team ran BLAST searches on the nearly complete Giardia lamblia genome project and detected homologs of five meiosis-specific genes found in plants, animals, and fungi: Dmc1 promotes interhomolog recombination; Spo11 creates DNA double-strand breaks; Hop1 is part of the synaptonemal complex; and Hop2 and Mnd1 ensure accurate and efficient homology searching. The researchers say these meiosis-specific genes, in conjunction with the presence of known meiosis-related genes, provide strong evidence that the protist has or very recently had the capacity for sexual reproduction.

"What I would like to know in further studies is if the presence of these genes indicates meiotic sex or premeiotic parasex, in which many of the...