Featuring information on Anne McCaffrey's Pern, including Dragonhealing, Herbalry, and Dracogenetics.

DRAGONHEALING
     Introduction
     Craftstandards (12th Pass)
     Dragon Anatomy

HERBALRY ON PERN
     Introduction
     Harvesting
     Preparation
     Properties
     Common Remedies
     Tissue Damage
     Miscellaneous Remedies

DRACOGENETICS
     Introduction
     Gender
     Metallics & Rank
     Colors
     White Dragons
     Conclusions

HERALDRY
     Introduction
     Established Heraldry
     Blank Shields
     Heraldic Colors

GUESTBOOK
     Sign
     View 2001-?
     View 1999-2000
     View 1998

PERN LINKS
     Anne McCaffrey's Site
     SunCliff Weyr
     Logres Weyr

OTHER LINKS
     My Personal Site
     Sigma Psi
     CWRU
     Email Me

This text is compiled from factual, statistical, or other information originally from work done and/or owned by Anne McCaffrey. Credit is also given to Dr. Jack Cohen, who developed the theoretical basis for the McCaffrey-Cohen model. Statements expressed herein are ideas that may or may not coincide with those of Anne McCaffrey or Dr. Jack Cohen, and those ideas that have no readily available backing by either of the aforementioned are in no way to be interpreted as direct statements of the views, opinions, and/or statements made by the aforementioned.

Essentially, dragonhide has three layers that give it color: a gold layer, a brown layer, and a chromatic layer.

Queen:
First, the queen must be female: XX. The queen must also possess both alleles for gold deposition: XGXg. In order for this to work, however, additional components are required. These genes also contribute to development in terms of size and rank. Of two components, both are required: XGXg Rr. Dragonhide coloration is layered, that is, each layer contributes to a component of color. The topmost layer is the gold layer, and it is completely opaque. (Patchy skin on a dragon from flaking makes itself apparent by the removal of hide layers. Slight color variation indicates patchiness.) A female dragon only requires the gold deposition and rank genes to be a queen. Any other genes may or may not deposit color, but this color will not show through the opaque outer layer of gold.

Green:
First, the green must be female: XX. In the green dragon, either or both the gold deposition and rank genes must be incomplete sets: XGXg RR, XGXG rr, XgXg RR, XGXG Rr, XgXg rr. A green can NOT have a complete set of alleles [XGXg Rr]. Remember that to produce a high-ranking dragon, all components must be present. In the green dragon, one or more of these necessary components is missing, so any gold metal is not recovered by the dragon and deposited in the outer layer. Thus the chromatic later and its characteristic green hue is more readily apparent.

Bronze:
Bronze dragons must be male: XY. The bronze only requires one of the gold deposition genes, because its corresponding component is on the Y chromosone: XgY. Again, like the queen, both rank alleles must be present: XgY Rr. The Y component of gold deposition is a less effective component that its female counterpart, XG. Deposition of the upper layer of gold in a bronze is therefore translucent, and underlying layers may show through. Beneath the goldlayer is a brown layer, where a pigment is deposited. Here a third gene comes into play, B. B is incompletely dominant to b. In a bronze, the combination Bb is required for a translucent layer of brown: XgY Rr Bb. The chromatic layer beneath the brown layer is green, and some may show through the hide. The resulting color combination of gold, brown, and green brings out the color of bronze.

Brown:
Brown dragons must be male: XY. The brown, like the green, is missing a component in its genome necessary for development into a bronze: XGY RR, XGY Rr, XGY rr, XgY RR, XgY rr. Gold metal fails to deposit on the gold layer. This time the brown layer is opaque, this making it the most apparent and covering up the chromatic layer. This allele combination required for an opaque brown layer is BB: XGY RR BB, XGY Rr BB, XGY rr BB, XgY RR BB, XgY rr BB. An interesting pattern that emerges is that statistically, brown-gold matings have not produced queens. However, in theory, it is possible. If we postulate that the queen's genotype is XGXg Rr BB or XGXg Rr Bb or XGXg Rr bb (recall that in females the B gene is irrelevant), then to produce a queen:

Brown contributes XGR Queen contributes Xgr. Resultant genotype: XGXg Rr.  However, due to the superior stamina of the bronze, bronze-gold matings tend to occur almost consistently.

Blue:
Blue dragons must be male: XY. The blue dragons also lack the genes for high rank: XGY RR, XGY Rr, XGY rr, XgY RR, XgY rr. The blue dragon, like the green, lacks any source of color in either the gold or brown layers of its hide, thus the chromatic layer shows through. However, the Y chromosome appears now to contribute an additional factor to the color of the chromatic layer. The absence of the other components for gold deposition in a male dragon allows the Y component to trigger a change in development, replacing the copper-protein pigment of the chromatic layer with copper sulfate, which is blue. The mechanism by which this is accomplished involves first eliminating the protein-based pigments in the dragon's hide and then releasing sulfates to bond to the copper. In a brown dragon, the double dominant expression of BB is enough so that this does not eliminate the protein from the brown layer. However, in a Bb situation, not enough protein exists, and it is completely removed. In a bb situation, no pigment is produced in the brown layer. Thus the blue dragon has the allele combinations: XGY RR Bb, XGY Rr Bb, XGY rr Bb, XgY RR Bb, XgY rr Bb, XGY RR bb, XGY Rr bb, XGY rr bb, XgY RR bb, XgY rr bb.