Spermatogenesis in Mature and Regressed Testes of the Vole (Microtus Agrestis)

Seasonal variation in the histology of the testis of the red deer, Cervus elaphus

“…The two types of stem spermatogonia are nearly identical to those observed in the adult bull (Hochereau-de Reviers, 1970) and ram (Hochereau-de Reviers, Ortavant & Courot, 1976 (Ortavant, 1958 ;Hochereau-de Reviers, Loir & Pelletier, 1976) and vole (Grocock & Clarke, 1975). The seasonal changes in the stem spermatogonia are of special interest because they differ from those described for the ram in which the total number of both A0 and spermatogonia per testis increase in the sexual season .…”

Photoperiodic Regulation of Neuroendocrine-Gonadal Activity

“…Testicular atrophy, induced in many species by an exposure to a nonstimulatory photoperiod, is accompanied by a cessation of spermatogenesis and a decline in serum androgen levels (Lodge and Salisbury, 1970;Desjardins et al, 1971;Berndtson and Desjardins, 1974;Grocock and Clarke, 1975;Lincoln et al, 1977). In many female mammals, an exposure to a nonstimulatory light cycle induces acyclicity which is accompanied by a cessation of ovulation and marked changes in serum estrogen and progesterone levels (Seegal and Goldman, 1975;Sharp and Ginther, 1975;Van Horn, 1975;Van Horn and Resko, 1977;Legan et al, 1977;Oxender et al, 1977).…”

Seasonal Changes in Spermatogenesis (Including Germ Cell Degeneration) and Plasma Testosterone Concentration in the Grey-headed Fruit Bat, Pteropus poliocephalus

“…Adult males show seasonal changes in testis size with maximal testis size occurring during autumn just prior to the time of mating (Nelson 1963). Spermatogenic dynamics and germcell degeneration have been examined in laboratory animals, such as the rabbit (Swiestra and Foote 1963) and the rat (Russell and Clermont 1977), domestic species (sheep, Ortavant 1956) and in some wild species (vole, Grocock and Clarke 1975). Although qualitative descriptions of spermatogenesis in chiropterans are available (Krutzsch 1961(Krutzsch , 1975Bradshaw 1962;Racey 1974;Racey and Tam 1974;and Singwi and Lall 1983) no spermatogenic kinetic studies have been performed on this large order of mammals.…”