Related Experiment Video
Updated: Jul 4, 2026

Transabdominal Ultrasound for Pregnancy Diagnosis in Reeves' Muntjac Deer
Published on: January 7, 2014
Sry-negative XX true hermaphroditism in a roe deer
G Pajares1, A Balseiro, L Pérez-Pardal
1Asociación del Corzo Español, Departamento de Ecología, Universidad Complutense de Madrid, Spain.
Abstract:
A two-year-old roe deer was brought down in the course of a hunt in the north of Spain (Asturias). On physical examination the individual presented well-developed bared antlers, but surprisingly a female external genitalia. Several anatomical, histological and genetic analyses were performed in order to explain the observed phenotype. Necropsy evidenced ovary-like structures with follicles on the surface; histological analyses of testes evidenced positive immunolabel against testosterone in Leydig cells; genetic analyses showed that the sex of the individual was consistent with a female individual. PCR analysis failed to detect SRY sequences; no PIS deletion, which is responsible for XX sex-reversal in goats, was detected. On the basis of its presumptive normal female sexual karyotype (XX) and the presence of two functional abdominal bilateral testes and ovaries, the roe deer was finally diagnosed as possessing an XX hermaphroditism syndrome. However, as in many other cases, the specific reason for the occurrence of this case of hermaphroditism could not be determined.
More Related Videos
Related Concept Videos
Epistasis
Understanding Species and Reproductive Barriers
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Frequency-dependent Selection
Dosage Compensation
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...

