Rocha Emanuel Lucas Bezerra, da Silva Lucas Gabriel Verissimo Pinheiro, Barreto Isadora Natália Rocha, Magalhães Marcela Dos Santos, Dias Lucas Castanhola, Matias de Oliveira Radan Elvis, Braz Janine Karla França da Silva, de Oliveira Moacir Franco, de Moura Carlos Eduardo Bezerra
Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Avenida Francisco Mota, 572, Costa e Silva, Mossoró, Rio Grande do Norte 59625-900, Brazil.
Instituto Federal do Rio Grande do Norte (IFRN), Avenida Senador Salgado Filho, 1559, Tirol, Natal, Rio Grande do Norte 59015-000, Brazil.
Microsc Microanal. 2024 Mar 7;30(1):169-177. doi: 10.1093/micmic/ozae002.
This study aimed to investigate sexual dimorphism in stillborn hawksbill sea turtles (Eretmochelys imbricata) through gonadal morphological characterizations. Macroscopic, light microscopy, and transmission electron analyses were performed for 30 gonad-mesonephros complexes. Female gonads were spindle-shaped and present a translucent whitish appearance with a grainy texture. Male gonads were approximately ovoid with a smooth opaque white surface. A primary sexual difference concerns different marrow structures, with females presenting organized cellularity featuring oocytes, lacunae, and blood vessels, while males presented a distinct organizational medulla pattern marked by testicular cords extending throughout the gonad length. Ultrastructurally, female's stroma presented interstitial cells and an abundant cytoplasm rich in electrodense droplets and large oval germline cells, with a conspicuous and noncentral nucleus. Males, on the other hand, presented testicular cord cells containing small amounts of heterochromatin and approximately triangular apical and basal cytoplasms with an evident nucleolus characteristic of support cells. Additionally, there were cells with a large spherical nucleus compared with the cell size and a relatively scarce cytoplasm, identified as gonocytes. These findings indicate that macroscopic, microscopic, and ultrastructural evaluations are effective and reliable techniques for the sexual identification of stillborn E. imbricata hatchlings.
本研究旨在通过性腺形态特征研究玳瑁（Eretmochelys imbricata）死产幼龟的性别二态性。对30个性腺-中肾复合体进行了宏观、光学显微镜和透射电子分析。雌性性腺呈纺锤形，外观半透明发白，质地颗粒状。雄性性腺近似卵形，表面光滑不透明呈白色。一个主要的性别差异在于不同的骨髓结构，雌性呈现出有组织的细胞结构，有卵母细胞、腔隙和血管，而雄性呈现出独特的组织髓质模式，其特征是睾丸索贯穿性腺全长。在超微结构上，雌性的基质呈现间质细胞和丰富的细胞质，富含电子致密小滴和大的椭圆形生殖细胞，细胞核明显且不在中央。另一方面，雄性呈现睾丸索细胞，含有少量异染色质，顶端和基部细胞质近似三角形，具有支持细胞明显的核仁特征。此外，还有一些细胞，其细胞核相对于细胞大小较大，细胞质相对稀少，被鉴定为生殖细胞。这些发现表明，宏观、微观和超微结构评估是用于玳瑁死产幼龟性别鉴定的有效且可靠的技术。
