Temporal germ cell development strategy during continuous spermatogenesis within the montane lizard, Sceloporus bicanthalis (Squamata; Phrynosomatidae)

Seasonal spermatogenesis in the Mexican endemic oviparous lizard,Sceloporus aeneus(Squamata: Phrynosomatidae)

“…[1][2][3]11,20 We agree with the efforts in using multiple indicators to describe the spermatogenic cycle of lizards, especially designs that include histological examination of reproductive organs. [1][2][3][4][5][6][7][8][9][10][11][20][21] However, the use of a single indicator may be misleading. For example, some of the data collected for S. aeneus (testis mass) suggest that February should be included in the months classified as maximum testicular activity (Table 1).…”

“…The presence of sperm in February and June in S. aeneus may signify a prolonged maturational phase to spermatogenesis, which may represent an intermediary step toward the continuous spermatogenesis observed in S. bicanthalis. 20,21 Continuous spermatogenesis in S. bicanthalis (which probably is related to the extended presence of the receptive females in the population 40 ) is a complete prolongation of the reproductive season and may represent the penultimate stage of prolonged reproductive activity in male Sceloporus 19,41 and may represent a step in the progression of male reproductive cycles in response to the evolution of viviparity. Future studies, including populations of S. aeneus and S. bicanthalis, that are similar in geographic location, may provide insight into this hypothesis.…”

Reptilian spermatogenesis

“…S3, step 3 spermatid; S2, step 2 spermatid; S1, step 1 spermatid; SS, secondary spermatocyte; Di, diplotene; PA, pachytene; LP, leptotene; PL, pre-leptotene spermatocytes; SpB, type B spermatogonia; SpA, type spermatogonia. In continuous breeding reptiles, such as Sceloporus bicanthalis 33 and Anolis lineatopus 31 (Fig. 7), once a cycle of spermatogenesis is complete the basal compartment shows an increased rate of mitosis and meiosis, which amplifies the seminiferous epithelial height.…”

“…8, s1-s7) and include reptiles representing multiple orders within class Reptilia. 7,[27][28][29][30][31]33 Detailed ultrastuctural studies of the complete process of spermiogenesis within the Reptilia are rare. Many studies have incomplete descriptions of different aspects of spermiogenesis within the testis of reptiles.…”

The reproductive cycle of the male house gecko, Hemidactylus flaviviridis, in relation to plasma steroid concentrations, progesterone receptors, and steroidogenic ultrastructural features, in Oman

“…The majority of these studies have concentrated on testicular growth and development followed by regression during the reproductive cycle. The spermatogenic activities leading to spermiation and mating behavior were the main emphasis in these investigations (Flemming, 1993;Gribbins et al, 2011;Nkosi et al, 2004;Ramírez-Bautista et al, 1996). In addition, some of the morphological studies have attempted to link specific features related to testicular activities such as the development of specific histological and ultrastructural features of the testicular tissues (including germ cells, Sertoli and Leydig cells) in relation to the seasonal activities (Akbarsha et al, 2006;Rheubert et al, 2009;Prasad, 1966, 1967).…”