Cytological organization of the seminiferous epithelium in the Australian rodents Pseudomys australis and Notomys alexis

Abstract

Absolute and relative testis mass of two species of conilurine rodents, the plains rat (Pseudomys australis) and the hopping mouse (Notomys alexis), were markedly different. In plains rats the testis comprised approximately 3% of body mass while in hopping mice they rarely accounted for more than 0.2%. In both species, 8 cellular associations, or cycle stages, were recognized in the seminiferous epithelium. The relative frequencies, and hence durations, of Stages I to VIII were 5.1, 7.0, 12.5, 10.5, 5.4, 25.9, 4.4 and 29.0% of one cycle for plains rats (N = 14), and 20.4, 10.9, 9.6, 8.1, 5.1, 20.4, 14.7 and 10.8% for laboratory-bred hopping mice (N = 35). Generally, the relative durations of the cycle stages were very similar between plains rat individuals, but were variable between hopping mice. Also, organization of the seminiferous epithelium was less rigid in hopping mouse testes, and several anomalies were observed. These included: the occurrence of 2-4 cellular associations in about 20% (range 11.3-33.9%) of tubular cross-sections, deviations in cellular composition in certain cycle stages from that usually observed, and an increased incidence of degenerating cells, together with the presence of multinucleated "giant' cells, within the seminiferous epithelium.

Postnatal testicular development in mouse species with different levels of sperm competition

“…Among primates, species with relatively larger testes have a greater proportion of seminiferous tubules than species with lower relative testes mass (Schultz 1938) and, in the great apes, the proportion of seminiferous tubules varies in agreement with relative testes mass being highest in the chimpanzee and lowest in the gorilla (Fujii-Hanamoto et al 2011). Among rodents, the proportion of testicular volume occupied by seminiferous tubules was greater in Pseudomys australis (the Plains Rat), a species with high relative testes mass, than in Notomys alexis the Spinifex Hopping Mouse, which has a low relative testes mass (Breed 1982, Peirce & Breed 1987, 1990). Furthermore, in comparative studies in birds, species with higher combined testes mass in relation to body mass exhibited an increase in the proportion of seminiferous tissue (Lü pold et al 2009b, Rowe & Pruett-Jones 2011.…”

Unique features of spermiogenesis in the Musky Rat‐kangaroo: reflection of a basal lineage or a distinct fertilization process?

“…Spermatogenesis was categorized into eight stages, though these differed slightly from those reported in other mammals analysed using the Roosen-Runge & Giesel (1950) method (Roosen-Runge & Giesel, 1950;Setchell & Carrick, 1973;Tait & Johnson, 1982;Peirce & Breed, 1987;Wrobel et al 1993;Kerlin, 1999).…”

“…Spermatogenesis occurs in a regular pattern in each mammalian species, with the same cellular associations occurring sequentially and repeatedly. Again, though spermatogenesis is really continuous, for convenience it is classified into identifiable 'stages' by most authors (Roosen-Runge & Giesel, 1950;Leblond & Clermont, 1952a;Setchell & Carrick, 1973;Orsi & Ferreira, 1978;Tait & Johnson, 1982;Peirce & Breed, 1987;Patil & Saidapur, 1991;Saidapur & Patil, 1992;Bilaspuri & Kaur, 1994;Lin et al 2004). Although few marsupial species have been studied, stages appear broadly consistent with eutherians (Setchell & Carrick, 1973;Orsi & Ferreira, 1978;Lin et al 2004;Ricci & Breed, 2005).…”

Unusual germ cell organization in the seminiferous epithelium of a murid rodent from southern Asia, the greater bandicoot rat,Bandicota Indica

“…, 1999), lesser bandicoot rats (Sinha Hikim et al. , 1985), plains rats (Peirce & Breed, 1987) and hopping mice (Peirce & Breed, 1987). In all of these species, with the exception of the hopping mouse Notomys alexis (Peirce & Breed, 1987), a similar germ cell organization to that of the laboratory rat and mouse was found to occur.…”

“…Cell associations within the testes have been described for various rodent species besides common laboratory mice and rats, including hamsters (Clermont & Trott, 1969;Oud & de Rooij, 1977), prairie voles (Schuler & Gier, 1976), field voles (Grocock & Clarke, 1975, bank voles (Grocock & Clarke, 1976), grey squirrels (Tait & Johnson, 1982), mole rats (Redi et al, 1986), Asian gerbils (Bilaspuri & Kaur, 1994), viscachas (Munoz et al, 1998), capybaras (Paula et al, 1999), lesser bandicoot rats (Sinha Hikim et al, 1985), plains rats (Peirce & Breed, 1987) and hopping mice (Peirce & Breed, 1987). In all of these species, with the exception of the hopping mouse Notomys alexis (Peirce & Breed, 1987), a similar germ cell organization to that of the laboratory rat and mouse was found to occur.…”