The origin and nature of cortical vacuoles in the Amphioxus egg

Summary The origin and nature of cortical vacuoles have been studied in the Amphioxus egg. They originate adjacent to the plasma membrane of the growing oocyte and are finally arranged in the cortical ooplasm of the egg. The cortical vacuoles do not contain any material demonstrable with cytochemical techniques for lipids, carbohydrates, proteins, or nucleic acids. The cortical vacuoles of the Amphioxus egg are comparable to those of the fish egg.     

Effect of uterine fluid on in vitro acrosome reaction of buffalo (Bubalus bubalis ) spermatozoa

The present study was undertaken to examine in vitro acrosome reaction in the uterine fluid of estrous buffalo. Successful acrosome reaction was achieved by incubating buffalo spermatozoa in 2% detoxified uterine fluid in Biggers Whitten Whittingham (BWW) medium, pH 7.4 at 37 degrees C and a sperm concentration of 36 x 10/ml. Neat uterine fluid has been found to be toxic to spermatozoa, hence we detoxified the uterine fluid at 56 degrees C for 30 min, which resulted in higher percentage of sperm motility, viability, and acrosome reaction. All the three stages of acrosome reaction i.e., acrosome swelling, vesiculation and shedding, were observed and they reached an apparent maximum at 4, 7 and 8 h of incubation, respectively. The significance of the findings in relation to the role of female reproductive tract in acrosome reaction is discussed.     

Induction of buffalo (Bubalus bubalis ) sperm capacitation and acrosome reaction in the excised reproductive tract of hamsters

A study was conducted on the induction of buffalo sperm capacitation and acrosome reaction in the excised reproductive tract of hamsters at the estrogen- and progesterone-dominated stages of estrus. The percentages of the maximum capacitation and acrosome reaction were significatly (P < 0.01) higher for spermatozoa incubated in the uterus with oviducts of estrogen dominated hamsters compared with those incubated in BWW medium in a test tube (64.6%, 60.2%; 16.2%, 14.7%). Buffalo spermatozoa incubated in the uterus and oviducts of progesterone-dominated hamsters showed significantly (P < 0.01) lower capacitation and acrosome reaction rates than those incubated in the uterus and oviducts of estrogen-dominated hamsters (34.8%, 34.3%: 64.6%, 60.2%). The percentage of capacitation and acrosome reaction in spermatozoa were significantly (P < 0.01) more when incubated in the uterus plus oviducts than without the oviduct irrespective of whether the reproduct tract of hamster was estrogen- or progesterone-dominated. The time for the onset of maximum capacitation and acrosome reaction was reduced from 12 to 10 h when the spermatozoa were incubated in the hamster reproductive tract rather than in BWW medium in test tubes. The significance of the results in relation to hormonal regulation of sperm capaciation and acrosome reaction are also discussed.     

A Simple Staining Procedure for Detecting the true Acrosome Reaction in Buffalo (Bubalus bubalis) Spermatozoa

A simple dual staining procedure for detecting the true acrosome reaction in dried smears of buffalo spermatozoa is described. Trypan blue is used first to differentiate live from dead spermatozoa and the dried smears which have been prepared are stained with Giemsa for acrosome evaluation. Four categories of spermatozoa were recognized: A) live, intact acrosome (acrosome pink, postnuclear cap clear); B) dead, intact acrosome (acrosome pink, postnuclear cap blue); C) live, detached acrosome (acrosome clear, postnuclear cap clear); and D) dead, detached acrosome (acrosome clear, postnuclear cap blue). The procedure is simple, rapid and convenient for assessing true acrosome reaction in buffalo spermatozoa. Simultaneous assessment of sperm viability and its acrosomal status in dried smears makes this procedure attractive because the true acrosome reaction can be studied thoroughly at a later state after the incubation period.     

Effect of long photoperiod on the maturation of ovary of the catfish, Mystus tengara (Ham.)

A study has been made of the effect of photoperiodism on the ovarian maturation of fresh water teleost, Mystus tengara (Ham.). The magnitude of ovarian recrudescence is more during maturing virgin phase as compared to during immature virgin and preparatory virgin phases in long photoperiod (14 hours/day) treated fish. Thus, the response of the ovary to long photoperiod increases with the approach of natural spawning period. The mature eggs are more in long photoperiod treated fish than in controls exposed to 12 hours/day photoperiod. In long photoperiod treated fish, prespawning period is reduced considerably. During spawning and post-spawning periods, the ovaries are refractory, since long photoperiod is ineffective in maintaining gravid ovaries beyond spawning period and the ovarian regression during post spawning period sets in regardless of nature of photoperiod treatment.