2026/07/24 by Yurany Nathaly Hernández‐Díaz, Nathaly Hernández‐Díaz, Diego F. Villabona‐Ríos +1
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Amphibian and Reptile Biology #Developmental Biology and Gene Regulation #Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
paper · doi:10.1111/azo.70039
crossref issued 2026/07/24 · crossref published 2026/07/24 · crossref published-online 2026/07/24 · openalex publication_date 2026/07/24 · crossref created 2026/07/25 · crossref deposited 2026/07/25 · crossref indexed 2026/07/25 · openalex created_date 2026/07/26 · openalex updated_date 2026/07/26
ABSTRACT Gonadal development and differentiation in vertebrates begin with the formation of a bipotential gonad that subsequently differentiates into either testes or ovaries. Studies addressing gonadal development in lizards are scarce and have focused primarily on oviparous taxa. Here, we provide the first description of gonadal development in Marisora sp., an obligate placentotrophic viviparous lizard. Histological analyses were performed on embryos from developmental Stages 30 to 40, following the standardised staging table for lizards. At Stage 30, the gonad is bipotential and undifferentiated until Stage 33, when a clear regionalisation into cortex and medulla appears. Gonadal differentiation begins at Stage 34. In males, medullary testicular cords develop, followed by the maturation of Sertoli cells, and the differentiation of Leydig cells within the interstitial tissue by Stage 38. In females, the cortical region consists primarily of oogonia, oocytes and somatic cells. From Stage 37 onward, germinal beds form and folliculogenesis initiates with primordial follicles; subsequent stages show continuous follicular recruitment and growth and the development of advanced previtellogenic follicles. The Wolffian and Müllerian ducts are identifiable at Stage 30, with differentiation of the Müllerian duct occurring at Stages 31–35. In males, the Müllerian duct regresses completely; in females, both ducts persist. Overall, gonadal development in Marisora sp. follows patterns described for lizards. Nevertheless, our findings demonstrate an accelerated ovarian developmental trajectory, with follicles reaching previtellogenic stages before birth. This pattern is consistent with the species' early sexual maturation and represents a pronounced heterochronic shift in female gonadal development relative to other squamates.