https://www.selleckchem.com/ALK.html The brown alga Ectocarpus has a haploid-diploid life cycle that involves alternation between two multicellular generations, the sporophyte and the gametophyte. Life cycle generation is not determined by ploidy but by a genetic system that includes two different three amino acid loop extension homeodomain transcription factors called OUROBOROS and SAMSARA. In addition, sporophytes have been shown to secrete a diffusible factor into the medium that can induce gametophyte initial cells to switch from the gametophyte to the sporophyte developmental program. The protocol presented here describes how to produce sporophyte-conditioned medium containing the diffusible sporophyte-inducing factor and how to assay for activity of the factor using a meio-spore-based bioassay. The protocol, which describes how several steps of these procedures can be optimised, will represent a useful tool for future work aimed at characterising the diffusible factor and investigating its mode of action.Songbirds, such as the zebra finch, are a popular animal model for studying the neural basis of vocal and complex skill learning. Adult male zebra finches produce courtship song toward females (referred to as 'directed song') and recording and analyzing sounds of directed song along with underlying neural activity is important for investigating behavioral and neural mechanisms of song production and learning. However, recording of directed song is easily contaminated by calls that are often as loud as directed songs and frequently produced by a female bird is presented in the same sound-recording chamber to elicit directed song. We developed a new surgical procedure to relatively easily and almost completely devocalize female zebra finches semi-permanently, without affecting other behaviors. This procedure enables researchers to record directed songs with almost no contamination by female calls. The procedure can also be used to devocalize male birds as well a