Studies on circaannual changes in reproduction of Rainbow trout (Oncorhynchus mykiss), an economically important fish of Kashmir have been carried out. The variations in testicular structure and function of rainbow trout were studied during the present investigation. Morphometric and gravimetric data revealed four distinct reproductive phases viz. (I) Resting or Spent stage (II) Maturation stag...

The spermatogenic lineage is established after birth when gonocytes migrate to the basement membrane of seminiferous tubules and give rise to spermatogonial stem cells (SSC). In adults, SSCs reside within the population of undifferentiated spermatogonia (A(undiff)) that expands clonally from single cells (A(single)) to form pairs (A(paired)) and chains of 4, 8 and 16 A(aligned) spermatogonia. A...

Many salmonid species have recently become at risk of extinction. For fish species where eggs cannot be cryopreserved, establishment of techniques to preserve genetic resources other than egg and embryo cryopreservation is imperative. In the present study, spermatogonia from male trout were transplanted into the peritoneal cavity of newly hatched sterile triploid salmon. Transplanted trout sper...

BACKGROUND Spermatogonia are highly tolerant to reactive oxygen species (ROS) attack while advanced-stage germ cells such as spermatozoa are much more susceptible, but the precise reason for this variation in ROS tolerance remains unknown. METHODOLOGY/PRINCIPAL FINDINGS Using the Japanese eel testicular culture system that enables a complete spermatogenesis in vitro, we report that advanced-s...

H-Y antigen negative XOSxr mice, like their H-Y positive XOSxr" counterparts, have testes; but, in contrast to XOSxr" males, XOSxr" testes almost totally lack meiotic and postmeiotic stages of spermatogenesis. The quantitative analysis of the testes of XOSxr males and their XY±Sxr sibs, described in. the present study, identified two distinct steps in this spermatogenic failure. First, there wa...

H-Y antigen negative XOSxrb mice, like their H-Y positive XOSxra counterparts, have testes; but, in contrast to XOSxra males, XOSxrb testes almost totally lack meiotic and postmeiotic stages of spermatogenesis. The quantitative analysis of the testes of XOSxrb males and their XY +/- Sxrb sibs, described in the present study, identified two distinct steps in this spermatogenic failure. First, th...