Allozymes and the genetics of antler development in red deer (Cervus elsphus)

In order to examine a previously hypothesized influence of selective hunting on allele frequency changes at some regularly polymorphic allozyme loci in red deer ( Cervus eluphus ), antler characters, serving as criteria for culling, were examined in relation to electrophoretic variation in two free-ranging populations of the Vosges, Eastern France, and an enclosure in Central France. When homozygous for the allele Idh-2 ¹²⁵, stags ≥ 2 years old had a significantly higher number of antler points (NAP). When homozygous for the allele Acp-2 ¹⁰⁰, stags older than 5 years had antlers that were significantly larger for a number of traits (NAP, main beam length and circumference, coronet circumference, brow tine length). Among younger stags, all antler traits in Acp-2 ¹⁰⁰ homozygotes were significantly smaller than in carriers of the alternative allele, Acp-2 ⁸⁵. Our data suggest the presence of at least two independent genetic components (one associated with early development of a high NAP, the other with generally large antler size in adults), affecting antler expression in red deer. Those genetic components, possibly major genes which are chromosomally linked with the allozyme loci studied, compensate or reinforce each other in their phenotypic effects. By playing a role in balancing benefits and costs of male reproductive success, they may be part of a genetic mechanism enabling the rapid adaptation of a population to various environmental and demographic conditions. The three populations studied originate from one another, and, based on an assessment of effective population sizes, it could be demonstrated that selective hunting for antler shape has changed allelic frequencies at the associated marker loci within a few generations.