A46-Lancaster Farming, Saturday Poultry Basic Research Dr. Sally E. Johnson, Assistant Professor, Developmental Biology Penn State Most of us associate chicken with a source of food. But, in re ality, the chicken serves many purposes, including that of experi mental model. Historically, avian embryos represent the classical develop mental biology model system. Avian embryos develop in a rapid fashion reminiscent of most verte brate animals including humans. And, due to their unique packag ing system, chick embryos can be easily monitored and observed throughout the course of gesta tion. In the mid 19505, two leading scientists documented the mor phological changes that occur dur ing the course of avian develop ment To this day, the develop SHADE TREES for Farm & Industry Red Oak, Pin Oak, Sugar Maple, Ash, Native Red Maple, Locust & More. 2" to 4" Caliper - 13' to 16' Some “Park Grade” Trees Many Pre-Dug for Summer Planting. Large Selection of Sizes - Mostly Small Lots LANDSCAPING Referral Credits If you buy 2 or more bottles from your local dealer or UNI, we give you 10 free flyers. Then tell your friends about this excellent product and if they are interested, give them a flyer. When they order Longer Life you receive credits. Example: If you buy 2 bottles for $34.95 and 7 of your friends each purchase 2 bottles, you receive $42.00 ($6 each) toward your next order. So you reduce that order free of charge with a $3.55 check for the extra credit (42-34.95 -3.50 = 3.55) Your friends will also receive flyers and credits towaro their free products. Dealers Wanted For more information, or to order products U.N.I. HEALTH PRODUCTS 539 Hilltop Road, Myerstown, Pa. 17067 717-866-4555 or 1-800-668-7373. We accept checks, Visa, Master Card or Discover card. To pay by card, Include card number and expiration date. contact lust 15, 1998 Benefits From mental atlas chronicled by Drs. Hamburger and Hamilton serves as a universal handbook for com parative staging of avian embryos. They were one of the first groups to note that the chick heart per forms rhythmic contractions with in the first three days of incuba tion, eye coloration occurs after five-day, and rudimentary feathers are present after nine days. Through their recorded observa tions of avian development, our understanding of the processes of fetal development in humans has been greatly enhanced. In vertebrates, regions of cells respond to their surrounding envi ronment in an instructive fashion, thus becoming committed to a specific cell fate. With regard to cardiogenesis (heart formation), the inductive signal to become a cardiocyte (heart cell) is received within the first 18 hours. After ex- *80 ..*140 each Evergreen Trees Also Available 95 Leisey Road Denver, Lancaster County, Pa 17517 717-336-5515 pansion of the cardioblast popula tion, the cells cease replication and begin to synthesize the pro teins necessary for contraction. The cells align to form a tube structure that ultimately loops and fuses to form the four-chambered heart One of the ongoing projects in our lab is to discern the mechanis tic basis for early heart formation, spedifically, what tells a cell to be come a cardiocyte. Through ex plant experiemnts and tissue graft ing, several small proteins have been identified as candidate-in ducing agents. By characterizing the factors that elicit a response in normally non-cardiogenic cells, we can de termine the functional role of cer tain growth factors and determine the means by which they promote heart formation. One of the recently discovered factors that promotes cardiogene sis is a protein called bone mor phogenic protein (BMP2). BMP2 is one of several growth factors which also is intricately involved in regulating formation of the skeleton. Interestingly, ectopic delivery of BMP2 to cells normally not fated to become cardiocytes in duces expression of genes charac teristic of cardiocytes. This would suggest that one means of promot ing heart formation is through lo calized production of BMP2. The ability of BMP2 to act on two dis F. 0.8. Denver PA Quantity Discounts jM PUBLIC AUCTION jM . *Tj ? m At Paradise Sales Barn, Paradise, Pa. pb Directions: Approximately 8 miles East of Lancaster, PA on Route 30 turn on Meadow Lane to sale on right! _ . _ 9:00 A.M. ntH (Hn 9:00 A.M. Forklifts Iffi ■