Sordaria Crossing-Over Genetics Links

Commercial Slide Set shoring Wild x tan cross showing:
    1.   pure tax & pure wild (black) mold growing on agar
    2.   crossing-over plates (single source from tax & black spores)
    3.   perithecia showing asci (some with and some without crossing over)
                Go to:  http://www.jdenuno.com/PDFfiles/Sordaria.pdf

    Note: I could not select individual photos from the above slide set
    so I made my own below from separate web images.

   First we start with pure cultures of wild (black) and tan (or grey) spored Sordaria. 
   The teacher will raise them in larger quantities than shipped from our supplier. 
   (Zowie teacher!)

             
       Sordaria wild type (black) spores  Sordaria tan spores squished from perithecia

   But what if we cross these wild x tan on a single agar plate?  
   We will then wait about 10 days for the Sordaria to go through a mating cycle
   and produce new spores.

                               
                After about 10 days, one gets Sordaria showing
            regions of wild (black) and tan spores

     In the regions where the Sordaria touch, wild type Sordaria mated
     (Yes Virginia, even something as simple as a dung mold can mate.) with tan spored
     Sordaria.  Some of the eight (8) spores in each ascus squished from a perithecia
     will not show crossing over (4 black then 4 tan in a line).  Other asci (plural of ascus)
     will show crossing-over and a different spore pattern.  The crossing-over pattern
     will either be 2:4:2 or 2:2:2:2 with alternating colors (black and tan). 

                    
    Note that some asci show the 4:4 pattern and some show the two crossing-over patterns.

                                        The end of our short life cycle tale. 

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