ULTRAESTRUCTURAL STUDY OF THE SEMINIFEROUS EPITHELIUM IN LIOLAEMUS CUYANUS THROUGHOUT REPRODUCTIVE ANNUAL CYCLE

MATÍAS DELLE COSTE; ANDREA ANABELLA BARAUNA; EDUARDO ALFREDO SANABRIA; LORENA BEATRIZ QUIROGA; CAROLINA ROMERO; MIGUEL FORNÉS

Buenos Aires

Congreso; ?Congreso del Comité Interamericano de Sociedades de Microscopía Electrónica (CIASEM XV)? y ?Congreso de la Asociación Argentina de Microscopía (SAMIC VI)?; 2019

Asociación Argentina de Microscopía

In arid zones availability of resources is limited in space and time due to the marked climatic seasonality. As a reproductive strategy, vertebrates adapt through an endogenous circannual rhythm, comprised of a single reproductive period, followed by a stage of complete sexual inactivity. In adult males, there are changes in the ultrastructure of seminiferous epithelium (SE) implies different gonadal status. The goal of this work is to determine if the SE of the testicle in Liolaemus cuyanus, from the Mount Desert, San Juan Province, exhibits the predictive annual variation. During its reproductive season, 29 adult males were collected. One gonad of each specimen was isolated and fixed in 2% glutaraldehyde in PAF-buffer phosphate. The samples were processed by standard techniques for EM and were observed with a Zeiss 900 Microscope. The histological samples were analyzed with ImageJ free software, version 1.37v showing morphological measurements changes such as perimeter / surface of SE. Micrograph, presented in October, basal spermatogonia, and few spermatocytes in meiotic division, round spermatids with condensed nuclei and developing acrosomes (Fig. 1). In November, some spermatocytes developed in group and others continued the meiosis. By December, a great number of sperm were espermiated into the tubular lumen (Fig. 2). In January the differentiation was maintained but in February and particularly March, intraepithelial spaces, apoptosis stages and some electron-dense deposits began to be evident. The process of spermiogenesis shows particularities of the species, such as cluster of membranes-proteins associated with the flagellum. We can infer that L. cuyanus presents an annual cycle with active SE in spring-summer and a total regression prior to the beginning of autumn and winter, seasons in which the period of lethargy occurs.