Integrating genomics and endocrinology to investigate prolactin dysregulation in female African Savannah elephants housed in north American zoos.

The sustainability of the captive African savannah elephant (Loxodonta africana) population in the United States has reached a critical point and is no longer viable under current conditions. A major contributing factor is the high proportion of reproductively aged female African savannah elephants that are not cycling due to prolactin dysregulation (hyperprolactinemia). Because prolactin secretion plays a key role in normal ovarian function in mammals, its dysregulation can negatively affect both individual health and overall reproductive success. No treatments for this condition are currently known in elephants. We conducted a genome-wide association study (GWAS) to identify genomic variants associated with hyperprolactinemia in a cohort of 95 female African elephants in the North American zoo population; however, no variants were significantly associated with either cyclicity or prolactin status. Potential reasons for this outcome include limited sample size, genetic heterogeneity of the trait, and complex interactions between environment and reproductive outcomes. The lack of significant SNP associations underscores the complexity of prolactin dysregulation in elephants and the need for larger, more comprehensive studies, including the investigation of DNA methylation and gene expression to assess environmental or social influences on gene expression. These findings provide a foundation for future research on prolactin disorders in African elephants.