Spermatogenesis inLeptodactylus chaquensis. Histological study

Abstract

The organization and the histological characteristics of Leptodactylus chaquensis testis throughout the reproductive cycle were analyzed in the presented study. Gonads of adult males, processed with routine techniques for optical microscopy, revealed that during the reproductive period the seminiferous tubules were characterized by presentation of a large number of cysts, germ cells at the same maturation stage supported by Sertoli cells. All the germ line cells were also present in the postreproductive period and maintained their morphological characteristics. Primary spermatogonia were large-sized cells found isolated or in small groups. The rest of the cells of the germ line formed cysts. Secondary spermatogonia showed morphological characteristics similar to their predecessors, although they were smaller. Primary and secondary spermatocytes showed images of the different stages of the first and second meiotic division respectively. One finding was the presence of intercytoplasmic bridges between the secondary spermatocytes. Primary spermatids were rounded cells with an acrosomal vesicle associated with the nucleus and had cysts that were characterized by large intercellular spaces. Secondary spermatids were elongated cells with a well defined acrosome, which in the spermatozoa had the shape of an arrowhead. Another peculiar characteristic of this species was the fusion of the walls of the seminiferous tubule with the efferent duct that formed a path for spermatozoa during spermiation. The presence in the seminiferous tubules of all stages of the spermatogenic line during the two periods of the cycle studied indicated that Leptodactylus chaquensis had a potentially continuous reproductive cycle.

Influence of rainfall and temperature on the spermatogenesis of Leptodactylus macrosternum (Anura: Leptodactylidae)

“…In our findings, the cell characteristics of L. Macrosternum, and the process of spermatogenesis, with variation in the quantities of cysts and especially the spermatozoa within the locules, are similar to L. podicipinus (Prado et al 2002), L. chaquensis and L. podicipinus (Ferreira et al 2009), Leptodactylus fuscus (Schneider, 1799) (Maragno and Cechin 2009) and L. chaquensis (Villagra et al 2014), demonstrating an organizational pattern of germ cells dependent on the seasonal variation of each region.…”

Gametogenesis and reproductive dynamics of Rhinella schneideri (Anura: Bufonidae): Influence of environmental and anthropogenic factors

“…For tropical anurans, some aspects related to spermatogenesis (Aguiar-Jr, Lima, Bao, & Recco-Pimentel, 2004;Ferreira, Mehanna, & Prado, 2008;Garda, Colli, Aguiar-Jr, Recco-Pimentel, & Báo, 2002;Oliveira, Vicentini, & Taboga, 2003;Oliveira, Zanetoni, & Zieri, 2002;Santos & Oliveira, 2008;Veiga-Menoncello, Lima, & Recco-Pimentel, 2006;Villagra et al, 2014) and oogenesis (Oliveira & Santos, 2004;Prado, Abdalla, Silva, & Zina, 2004;Villecco, Mónaco, & Sánchez, 2007) have already been described. In addition to gamete morphology, anurans have been models for several studies that characterise the reproductive dynamics of the species (Akef, 2014;Ferreira & Mehanna, 2012;Huang, Lin, & Yu, 1997;Jørgensen, 1981;Kanamadi & Saidapur, 1982;Kaptan & Murathanoglu, 2008;Medina, Ramos, Crespo, González-Calvar, & Fernández, 2004;Sasso-Cerri, Faria, Freymüller, & Miraglia, 2004;Villagra et al, 2014). These studies aimed at understanding the continuity or discontinuity of gamete production in individuals over time, allowing a more thorough approach to reproductive biology of the species.…”

“…Several aspects are employed to assess the reproductive dynamics, with the variation of gonadosomatic index being the most frequent one (El-Wailly, 2002;Saha & Gupta, 2011;Sretarugsa, Weerachatyanukul, Chavadej, Kruatrachue, & Sobhon, 2001;Villagra et al, 2014). Other studies also used the average variation in the seminiferous tubule diameter over time (Ferreira & Mehanna, 2012;Sasso-Cerri et al, 2004), the presence or absence of germ cells (Ferreira, Santos Rosa, & Mehanna, 2009), or even the quantification of germ cells (Díaz-Páez & Ortiz, 2001;Jørgensen, Shakuntala, & Vijayakumar, 1986).…”

“…The reproductive dynamics, also known as the reproductive cycle, have different classifications according to its duration for males and females. For males, the reproductive cycle can be classified as “continuous,” “discontinuous” or “potentially continuous” (Díaz‐Páez & Ortiz, ; Ferreira et al., ; Huang, Lin, & Yu, ; Huang et al., ; Kaptan & Murathanoglu, ; Villagra et al., ). These same studies also differentiate this classification according to the habitat, so the “discontinuous” type is found in species of temperate regions, and “continuous” and “potentially continuous” types are typical of tropical regions.…”

CARACTERIZAÇÃO HISTOMORFOLÓGICA DOS TESTÍCULOS DE Dendropsophus nanus (BOULENGER, 1889) (ANURA, HYLIDAE)

“…O epitélio germinativo da espécie estudada apresentou todas as células da linhagem germinativa, nos diferentes estágios de diferenciação, assim como observado em outros anfíbios anuros, Leptodactylus chaquensis (VILLAGRA et al, 2012), Ceratophrys ornata (CAREZZANO et al, 2013), Boana pulchella (CAREZZANO et al, 2015), Rhinella schneideri (MONTEZOL et al, 2017). Os diferentes cistos germinativos presentes no epitélio também foram detalhados volumetricamente, o mais abundante foi da espermatogônia B correspondendo a 44,8% do epitélio germinativo.…”